MEANS AND METHODS FOR VITAMIN B12 PRODUCTION IN DUCKWEED

Abstract

The present invention is directed to a system and method for producing vitamin B12 enriched Duckweed Bacterial Culture (DBC) composition. The aforementioned method comprises steps of inoculating at least one Lemnoideae species and at least one vitamin B12 producing bacteria species in a volume of growth media; incubating said at least one Lemnoideae species and said at least one vitamin B12 producing bacteria species under predetermined conditions to provide a Duckweed-Bacterial Culture (DBC); determining time intervals within said plots characterized by DBC with highest vitamin B12 content; and harvesting said DBC at said predetermined time intervals, thereby providing vitamin B12 enriched DBC composition. The present invention further discloses a composition comprising a vitamin B12 enriched Duckweed-Bacterial Culture (DBC), wherein said composition comprises at least one Lemnoideae species and at least one B12 producing bacteria species, further wherein said vitamin B12 content in said composition is in the range of between about 0.01 and about 100 g per 100 g of said DBC.

Claims

1-46. (canceled)

47. A method for producing vitamin B12 enriched Duckweed Bacterial Culture (DBC) composition, wherein said method comprises steps of: a. inoculating at least one Lemnoideae species and at least one vitamin B12 producing bacteria species in a volume of growth media; b. incubating said at least one Lemnoideae species and said at least one vitamin B12 producing bacteria species under predetermined conditions to provide a Duckweed-Bacterial Culture (DBC); c. plotting Lemnoideae plant biomass at said predetermined conditions against time; d. plotting bacterial count of said at least one B12 producing bacteria species at said predetermined conditions against time; e. plotting vitamin B12 content in said DBC at said predetermined conditions against time; f. determining time intervals within said plots characterized by DBC with highest vitamin B12 content; and g. harvesting said DBC at said predetermined time intervals, thereby providing vitamin B12 enriched DBC composition.

48. The method according to claim 47, wherein said step of incubating additionally comprises at least one step of: a. selecting said predetermined conditions designed for (i) optimal growth of said at least one Lemnoideae species plant, and (ii) optimal fermentation of said vitamin B12 synthesizing bacteria associated therewith; b. growing said at least one Lemnoideae species and said at least one vitamin B12 producing bacteria species under predetermined conditions to provide association between said at least one bacterial species and said at least one Lemnoideae species; c. selecting said predetermined conditions for growth of said Lemnoideae species biomass from the group consisting of: mineral composition of the growth media, mineral concentration of the growing media, urea concentration, nitrites and nitrates concentration, total ammonia concentration, temperature range of the growing media, temperature range of the atmosphere, water treatment procedure, illumination intensity, aeration, oxygen concentration, pH and any combination thereof; and d. selecting said predetermined conditions for symbiotic fermentation and vitamin B12 synthesis of said bacterial species from the group consisting of: sugar concentration in the range of about 0.01-3.0% w/v, amino acids and/or peptides and/or vitamins sources in a concentration range of about 0.01-3.0% w/v thereof, amino acids or mixes thereof in a concentration range of about 0.0001-0.3 g/l, microelements in a concentration range of about 0.0001-0.3 g/l, vitamins and any combination thereof.

49. The method according to claim 48, additionally comprises steps of selecting said association from the group consisting of: symbiotic interaction, persistent mutualism, persistent biological interaction, mutualism, interspecies reciprocal altruism, commensalistic interaction, parasitic symbiosis, obligate interaction, facultative interaction, obligate for both species, obligate for one but facultative for the other, facultative for both species, ectosymbiosis, endosymbiosis, commensal ectosymbiosis, mutualist ectosymbiosis, ectoparasitism, conjunctive symbiosis, disjunctive symbiosis, antagonistic or antipathetic symbiosis or relationship, necrotrophic interaction, biotrophic interaction, amensalism, competition relationship, antibiosis relationship, synnecrosis and any combination thereof.

50. The method according to claim 47, wherein said step of inoculating comprises at least one step of: a. growing said at least one Lemnoideae species and said at least one B12 producing bacteria species as a batch or as a continuous culture; b. selecting said volume of growth media from the group consisting of: an aqueous plant growing facility and a microbial growing facility; and c. selecting said volume of growth media from the group consisting of: a pool, a channel, an aquarium, a fermenter, a bioreactor, cobbles and any other substrate.

51. The method according to claim 48, additionally comprising at least one step of a. selecting said mineral from the group consisting of: Mg.sup.2+, Mn, Zn, Fe.sup.2+, Zn.sup.2+, Mn.sup.2+, CaCl.sub.2 and any combination thereof; b. selecting said water treatment procedure from the group consisting of: de-nitrification, mechanical, filtration and any combination thereof; c. selecting said sugar from the group consisting of dextrose, glucose, lactose and any combination thereof; d. selecting said amino acids and/or peptides and/or vitamins sources from the group consisting of Yeast extract, Enzymatic Digest of Casein, Enzymatic Digest of Gelatin and any combination thereof; e. selecting said amino acids or mixes thereof from the group consisting of L-ArginineoHCl, L-Cysteine, L-Glutamine, Glycine, L-HistidineoHCloH.sub.2O, L-Isoleucine, L-Leucine, L-LysineoHCl, L-Methionine, L-Phenylalanine, L-Serine, L-Threonine, L-Tryptophan, L-Tyrosine 2Nao2H2O, L-Valine and any combination thereof; and f. selecting said microelements from the group consisting of: Choline Chloride, Folic Acid, myo-Inositol, Niacinamide, D-Pantothenic Acid hemicalcium, Calcium Chloride, Ferric Nitrate, Magnesium Sulfate, Potassium Chloride, Sodium Chloride, Sodium Phosphate and any combination thereof.

52. The method according to claim 47, additionally comprising steps of selecting said bacteria from the group consisting of: Pseudomonas species such as P. aeruginosa, P. florescenza, P. murina, Bacillus species, Methanobacterium species, Propionibacterium species, Acetobacterium, Aerobacter, Agrobacterium, Alcaligenes, Azotobacter, Clostridium, Flavobacterium, Lactobacillus, Micromonospora, Mycobacterium, Nocardia, Propionibacterium, Protaminobacter, Proteus, Pseudomonas, Rhizobium, Salmonella, Serratia, Streptomyces, Streptococcus, Xanthomonas and any combination thereof.

53. The method according to claim 47, wherein said step of determining additionally comprises steps of determining the growth curves of said at least one Lemnoideae species and said at least one B12 producing bacteria species against time and identifying time intervals characterized by highest biomass of said at least one Lemnoideae species and highest bacterial cell count of said at least one bacteria species.

54. The method according to claim 47, additionally comprising steps of selecting said biomass from the group consisting of: whole Lemnoideae biomass, fresh Lemnoideae biomass, dry Lemnoideae biomass and any combination thereof.

55. The method according to claim 47, additionally comprising steps of selecting said at least one Lemnoideae species from a species belonging to the genera group consisting of: Landoltia, Lemna, Spirodela, Wolffia, Wolffiella and any combination thereof.

56. The method according to claim 47, additionally comprising steps of selecting said at least one Lemnoideae species from the group consisting of: Wollfia angusta, Wolffia arrhiza, Wolffia australiana, Wollfia borealis, Wollfia brasiliensis, Wollfia Columbiana, Wolffia cylindracea, Wollfia elongate, Wollfia globose, Wollfia microscopica, Wolffia neglecta and any combination thereof.

57. The method according to claim 47, additionally comprises steps of providing vitamin B12 enriched DBC composition comprising between about 0.01 and about 100 vitamin B12 per 100 g of said DBC.

58. A composition comprising a vitamin B12 enriched Duckweed-Bacterial Culture (DBC), wherein said composition comprises at least one Lemnoideae species and at least one B12 producing bacteria species, further wherein said vitamin B12 content in said composition is in the range of between about 0.01 and about 100 g per 100 g of said DBC.

59. The composition according to claim 58, wherein at least one of the following holds true: a. said vitamin B12 content in said composition is a predetermined percentage of at least 20% of the vitamin B12 recommended Daily Value (DV); b. said vitamin B12 content in said composition complies with the vitamin B12 recommended daily intake (RDI) standard for an adult ranging from about 0.4 g to about 3 g per day; c. said at least one B12 producing bacteria species is in association with said at least one Lemnoideae species; d. said association is selected from the group consisting of: symbiotic interaction, persistent mutualism, persistent biological interaction, mutualism, interspecies reciprocal altruism, commensalistic interaction, parasitic symbiosis, obligate interaction, facultative interaction, obligate for both species, obligate for one but facultative for the other, facultative for both species, ectosymbiosis, endosymbiosis, commensal ectosymbiosis, mutualist ectosymbiosis, ectoparasitism, conjunctive symbiosis, disjunctive symbiosis, antagonistic or antipathetic symbiosis or relationship, necrotrophic interaction, biotrophic interaction, amensalism, competition relationship, antibiosis relationship, synnecrosis and any combination thereof; e. said B12 producing bacteria are selected from the group consisting of: Pseudomonas species such as P. aeruginosa, P. florescenza, P. murina, Bacillus species, Methanobacterium species, Propionibacterium species, Acetobacterium, Aerobacter, Agrobacterium, Alcaligenes, Azotobacter, Clostridium, Flavobacterium, Lactobacillus, Micromonospora, Mycobacterium, Nocardia, Propionibacterium, Protaminobacter, Proteus, Pseudomonas, Rhizobium, Salmonella, Serratia, Streptomyces, Streptococcus, Xanthomonas and any combination thereof; f. said at least one Lemnoideae species is selected from the group consisting of: whole Lemnoideae biomass, fresh Lemnoideae biomass, dry Lemnoideae biomass and any combination thereof; g. said at least one Lemnoideae species belongs to a genera selected from the group consisting of: Landoltia, Lemna, Spirodela, Wolffia, Wolffiella and any combination thereof; and h. said at least one Lemnoideae species is selected from the group consisting of: Wolffia angusta, Wolffia arrhiza, Wolffia australiana, Wolffia borealis, Wolffia brasiliensis, Wolffia Columbiana, Wolffia cylindracea, Wolffia elongate, Wolffia globose, Wolffia microscopica, Wolffia neglecta and any combination thereof.

60. A composition comprising vitamin B12 enriched Duckweed Bacterial Culture (DBC) produced by the method according to claim 47.

61. The composition according to claim 60, wherein at least one of the following holds true: a. said predetermined conditions are selected from the group consisting of conditions for growth of said Lemnoideae species biomass, conditions for fermentation and vitamin B12 synthesis of said bacterial species and a combination thereof; b. said volume of growth media is a batch or a continuous culture; c. said volume of growth media is selected from the group consisting of: an aqueous plant growing facility and a microbial growing facility; and d. said volume of growth media is selected from the group consisting of: a pool, a channel, an aquarium, a fermenter, a bioreactor, cobbles and any other substrate.

62. The composition according to claim 61, wherein at least one of the following holds true: a. said predetermined conditions for growth of said Lemnoideae species biomass are selected from the group consisting of: mineral composition of the growing media, mineral concentration of the growing media, urea concentration, nitrites and nitrates concentration, total ammonia concentration, temperature range of the growing media, temperature range of the atmosphere, water treatment procedure, illumination intensity, aeration, oxygen concentration, pH and any combination thereof; and b. said predetermined conditions for fermentation and vitamin B12 synthesis of said bacterial species are selected from the group consisting of: sugar concentration in the range of about 0.01-3.0% w/v, amino acids and/or peptides and/or vitamins sources in a concentration range of about 0.01-3.0% w/v thereof, amino acids or mixes thereof in a concentration range of about 0.0001-0.3 g/l, microelements in a concentration range of about 0.0001-0.3 g/l, vitamins and any combination thereof.

63. The composition according to claim 62, wherein at least one of the following holds true: a. said mineral is selected from the group consisting of: Mg.sup.2+, Mn, Zn, Fe.sup.2+, Zn.sup.2+, Mn.sup.2+, CaCl.sub.2 and any combination thereof; b. said water treatment procedure is selected from the group consisting of: de-nitrification, mechanical, filtration and any combination thereof; c. said sugars are selected from the group consisting of dextrose, glucose, lactose and any combination thereof; d. said amino acids and/or peptides and/or vitamins sources are selected from the group consisting of Yeast extract, Enzymatic Digest of Casein, Enzymatic Digest of Gelatin and any combination thereof; e. said amino acids or mixes thereof are selected from the group consisting of L-ArginineoHCl, L-Cysteine, L-Glutamine, Glycine, L-HistidineoHCloH.sub.2O, L-Isoleucine, L-Leucine, L-LysineoHCl, L-Methionine, L-Phenylalanine, L-Serine, L-Threonine, L-Tryptophan, L-Tyrosine 2Nao2H2O, L-Valine and any combination thereof; and f. said microelements are selected from the group consisting of: Choline Chloride, Folic Acid, myo-Inositol, Niacinamide, D-Pantothenic Acid hemicalcium, Calcium Chloride, Ferric Nitrate, Magnesium Sulfate, Potassium Chloride, Sodium Chloride, Sodium Phosphate and any combination thereof.

64. A system for producing vitamin B12 enriched Duckweed Bacterial Culture (DBC) composition, wherein said system comprises: a. at least one inoculum of Lemnoideae species and at least one inoculum of vitamin B12 producing bacteria species for cultivation in a volume of growth media; b. an incubation means for incubating said at least one Lemnoideae species inoculum and said at least one vitamin B12 producing bacteria species inoculum under predetermined conditions to provide a Duckweed-Bacterial Culture (DBC); c. means for determining time intervals within said plots characterized by DBC with highest vitamin B12 content; and d. means for harvesting said DBC at said predetermined time intervals, thereby providing vitamin B12 enriched DBC composition.

65. The system according to claim 64, wherein said system additionally comprises at least one plotting means selected from the group consisting of: a. plotting means for plotting Lemnoideae plant biomass at said predetermined conditions against time; b. plotting means for plotting bacterial count of said at least one B12 producing bacteria species at said predetermined conditions against time; and c. plotting means for plotting vitamin B12 content in said DBC at said predetermined conditions against time.

66. A composition comprising a vitamin B12 enriched extract of at least one Lemnoideae species and at least one B12 producing bacteria species, further wherein said vitamin B12 content in said composition is in the range of between about 0.01 and about 100 g per 100 g of said DBC.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0075] The invention will now be described with reference to the drawings, wherein

[0076] FIG. 1 schematically illustrates a typical bacterial growth curve or kinetic curve as is known in the prior art; and

[0077] FIG. 2 schematically illustrates an exemplified Duckweed Bacterial Culture (DBC) growth curve or profile, as an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0078] In the following description, various aspects of the invention will be described. For the purposes of explanation, specific details are set forth in order to provide a thorough understanding of the invention. It will be apparent to one skilled in the art that there are other embodiments of the invention that differ in details without affecting the essential nature thereof. Therefore the invention is not limited by that which is illustrated in the figure and described in the specification, but only as indicated in the accompanying claims, with the proper scope determined only by the broadest interpretation of said claims.

[0079] The essence of the present invention is the provision of vitamin B12 enriched Duckweed Bacterial Culture (DBC) by the establishment of a novel Duckweed-Bacteria symbiotic or associated system and protocol, for the cultivation, growth and maintenance of same. The aforementioned system and protocol are designed for optimal growth of the duckweed biomass combined with productive cultivation of the B12 synthesizing bacteria. It should be emphasized that vitamin B12 cannot be produced by or in duckweed, but it is shown by the present invention that it can be effectively absorbed into the duckweed plant or be associated with the duckweed biomass after synthesis by the aforementioned bacteria. The resultant vitamin B12 enriched DBC is used as a naturally derived vitamin B12 source for human consumption, as a predetermined percentage of vitamin B12 recommended daily intake (RDI) standard. Preferably, the vitamin B12 enriched DBC composition contains between about 0.01 g and about 100 g vitamin B12 per 100 g of the DBC.

[0080] The present invention provides a method for producing vitamin B12 enriched Duckweed Bacterial Culture (DBC) composition, wherein the method comprises steps of: (a) inoculating at least one Lemnoideae species and at least one vitamin B12 producing bacteria species in a volume of growth media; (b) incubating the at least one Lemnoideae species and the at least one vitamin B12 producing bacteria species under predetermined conditions to provide a Duckweed-Bacterial Culture (DBC); (c) plotting Lemnoideae plant biomass at the predetermined conditions against time; (d) plotting bacterial count of the at least one B12 producing bacteria species at the predetermined conditions against time; (e) plotting vitamin B12 content in the DBC at the predetermined conditions against time; (f) determining time intervals within the plots characterized by DBC with highest vitamin B12 content; and (g) harvesting the DBC at the predetermined time intervals, thereby providing vitamin B12 enriched DBC composition.

[0081] As used herein, the term about refers hereinafter to a range of 25% below or above the referred value.

[0082] The term duckweed refers hereinafter to flowering aquatic plants which float on or just beneath the surface of water and wetlands. They belong to the family Araceae) and therefore, often are classified as the subfamily Lemnoideae within the Araceae. According to other classifications they are classified as a separate family, Lemnaceae.

[0083] The most known genera species of duckweeds family are: [0084] LEMNA (e.g. L gibba; L. disperna; L gibba; L japonica; L minima; L minor; L minuscula; L paucicostata; L perpusilla; L polyrrhiza; L turionifera; L. trisulca; L valdiviana) [0085] SPIRODELA (e.g. S. biperforata; S. intermedia; S. oligorrhiza; S. polyrrhiza; S. punctata) [0086] WOLFFIA (e.g. W. arrhiza; W. australiana; W. Columbiana; W. microscopia; W. neglecta, Wolffia angusta, Wolffia borealis, Wolffia brasiliensis, Wolffia cylindracea, [0087] Wolffia elongata, Wolffia globosa and Wolffia microscopica) [0088] WOLFFIELLA (e.g. W. caudate; W. denticulate; W. lingulata; W. oblonga; W. rotunda).

[0089] The term fresh weight refers hereinafter to duckweed plant in the form of the fresh vegetable where water content is included in the range of 93-97% by weight.

[0090] The term dry weight refers hereinafter to duckweed plant in the form of the dried vegetable where water content is included in the range of 2-8% by weight.

[0091] The term vitamin B12 refers hereinafter to the terms B12 or vitamin B-12, also called cobalamin. Vitamin B12 is a water-soluble vitamin which is required for proper red blood cell formation, neurological function, and DNA synthesis. It is normally involved in the metabolism of every cell of the human body, especially affecting DNA synthesis and regulation, but also fatty acid metabolism and amino acid metabolism. Vitamin B12 exists in several forms and contains the mineral cobalt; therefore compounds with vitamin B12 activity are collectively called cobalamins.

[0092] Neither fungi, nor plants or animals, are capable of producing vitamin B12. Only bacteria and archaea have the enzymes required for its synthesis, although many foods are a natural source of B12 because of bacterial symbiosis. The vitamin is the largest and most structurally complicated vitamin and can be produced industrially only through bacterial fermentation-synthesis.

[0093] It is further acknowledged that methylcobalamin and 5-deoxyadenosylcobalamin are the forms of vitamin B12 that are active in human metabolism.

[0094] In dietary supplements, vitamin B12 is usually present as cyanocobalamin, a form that the body readily converts to the active forms methylcobalamin and 5-deoxyadenosylcobalamin. Dietary supplements can also contain methylcobalamin and other forms of vitamin B12. However the body's ability to absorb vitamin B12 from dietary supplements is largely limited by the capacity of intrinsic factor. For example, only about 10 mcg of a 500 mcg oral supplement is actually absorbed in healthy people.

[0095] Pseudovitamin-B12 refers to B12-like analogues that are biologically inactive in humans and yet found to be present alongside B12 in humans, many food sources (including animals), and possibly supplements and fortified foods.

[0096] The term vitamin B12 producing bacteria species refers hereinafter to bacterial species that that are capable of producing vitamin B12 intracellularly or extracellularly by fermentation. It is herein acknowledged that species of the following genera are known to synthesize B12: Acetobacterium, Aerobacter, Agrobacterium, Alcaligenes, Azotobacter, Bacillus, Clostridium, Corynebacterium, Flavobacterium, Lactobacillus, Methanobacterium, Micromonospora, Mycobacterium, Nocardia, Propionibacterium, Protaminobacter, Proteus, Pseudomonas, Rhizobium, Salmonella, Serratia, Streptomyces, Streptococcus and Xanthomonas.

[0097] It is within the scope of the present invention that non limiting examples of vitamin B12 producing bacteria species include Pseudomonas species such as P. aeruginosa, P. florescenza, P. murina, Bacillus species, Methanobacterium species, Propionibacterium species, Acetobacterium, Aerobacter, Agrobacterium, Alcaligenes, Azotobacter, Clostridium, Flavobacterium, Lactobacillus, Micromonospora, Mycobacterium, Nocardia, Propionibacterium, Protaminobacter, Proteus, Pseudomonas, Rhizobium, Salmonella, Serratia, Streptomyces, Streptococcus, Xanthomonas and any combination thereof.

[0098] The term Duckweed Bacterial Culture or DBC refers hereinafter to any type of growth of at least one Lemnoideae species and at least one vitamin B12 producing bacteria species in a volume of growth media. The aforementioned co-culture includes any type of interaction, association or associated interaction between the at least one Lemnoideae species and the at least one vitamin B12 producing bacteria, as disclosed herein.

[0099] The term associated interaction or in association or symbiotic used herein generally refers hereinafter to close and often long-term interaction between two or more different biological species. The term refers to any type of species interaction including but not limited to, symbiosis, persistent mutualisms and persistent biological interaction such as mutualistic, commensalistic, or parasitic symbiosis.

[0100] In certain aspects, the relationships between the species are obligate, meaning that both symbionts entirely depend on each other for survival. Alternatively, they are facultative, meaning that they can, but do not have to, live with the other organism. It is further within the scope that relationships between the species include those associations in which one organism lives on another, i.e. ectosymbiosis, or where one partner lives inside the other, i.e. endosymbiosis. More specifically, endosymbiosis is any symbiotic relationship in which one symbiont lives within the tissues of the other, either within the cells or extracellularly. While, ectosymbiosis, is any symbiotic relationship in which the symbiont lives on the body surface of the host, including the inner surface of the digestive tract or the ducts of exocrine glands.

[0101] Reference is now made to mutualism or interspecies reciprocal altruism which refers to a relationship between individuals of different species where both individuals benefit. Mutualistic relationships may be either obligate for both species, obligate for one but facultative for the other, or facultative for both. According to certain aspects, during mutualistic symbioses, the host cell lacks some of the nutrients, which are provided by the endosymbiont. As a result, the host may favor the endosymbiont's growth processes within itself by producing some specialized cells. These cells may affect the genetic composition of the host in order to regulate the increasing population of the endosymbionts and ensuring that these genetic changes are passed onto the offspring via vertical transmission.

[0102] Reference is now made to commensalism, which describes a relationship between two living organisms where one benefits and the other is not significantly harmed or helped.

[0103] Reference is now made to a parasitic relationship, in which one member of the association benefits while the other is harmed. This term is also known as antagonistic or antipathetic symbiosis. It is further within the scope that parasitic symbioses includes many forms, from endoparasites that live within the host's body, to ectoparasites that live on its surface. In addition, it is within the scope of the present invention that parasites may be necrotrophic, meaning that they kill their host, or biotrophic, meaning they rely on their host's surviving.

[0104] Reference is now made to amensalism, which is the type of relationship that exists where one species is inhibited or completely obliterated and one is unaffected. It is within the scope that there are two types of amensalism, competition and antibiosis. Competition is where a larger or stronger organism deprives a smaller or weaker one from a resource. Antibiosis occurs when one organism is damaged or killed by another through a chemical secretion.

[0105] Reference is now made to synnecrosis, in which the interaction between species is detrimental to both organisms involved. It is a short-lived condition, as the interaction eventually causes death.

[0106] It is further within the scope that the interaction or association between the species may be also classified by physical attachment of the organisms. Interaction in which the organisms have bodily union is referred to as conjunctive, and interaction in which they are not in union is referred to as disjunctive symbiosis.

[0107] The term biomass refers hereinafter to the total mass of organisms, i.e. the at least one Lemnoideae species in a given area or volume, and might refer to the volume, fresh weight, dry weight, or any conventional measurement pertaining to the growth of the duckweed plants.

[0108] The term bacterial count refers hereinafter to any quantitative determination of bacterial populations or index of bacterial growth and cell numbers (biomass). This includes, but is not limited to the two widely used methods for determining bacterial numbers, namely the standard, or viable, plate count method and spectrophotometric (turbidimetric) analysis. A non limiting example of plate count is the colony-forming units (CFUs) technique. Spectrophotometric (turbidimetric) analysis may refer to increased turbidity in a culture. By using a spectrophotometer, the amount of transmitted light decreases as the cell population increases. The transmitted light is converted to electrical energy, and this is indicated on a galvanometer. The reading, called absorbance or optical density, indirectly reflects the number of bacteria.

[0109] The term growth medium or growth media refers hereinafter to water supplemented with components such as, but not limited to nitrogen, phosphorus, potassium, calcium, iron, zinc, copper, manganese, magnesium, urea, nitrites, nitrates, ammonia, sugars (such as dextrose, glucose, lactose) concentration in the range of about 0.01-3.0% w/v, amino acids and/or peptides and/or vitamins sources (such as yeast extract, enzymatic digest of casein, enzymatic digest of gelatin) in a concentration range of about 0.01-3.0% w/v thereof, amino acids or mixes thereof (such as L-ArginineoHCl, L-Cysteine, L-Glutamine, Glycine, L-HistidineoHCloH2O, L-Isoleucine, L-Leucine, L-LysineoHCl, L-Methionine, L-Phenylalanine, L-Serine, L-Threonine, L-Tryptophan, L-Tyrosine 2Nao2H2O, L-Valine) in a concentration range of about 0.0001-0.3 g/l, microelements (such as Choline Chloride, Folic Acid, myo-Inositol, Niacinamide, D-Pantothenic Acid hemicalcium, Calcium Chloride, Ferric Nitrate, Magnesium Sulfate, Potassium Chloride, Sodium Chloride, Sodium Phosphate) in a concentration range of about 0.0001-0.3 g/l, vitamins, (NH.sub.4).sub.2S0.sub.4; Ca(NO.sub.3).sub.2.4H2O; CaCl.sub.2.6H2O; CoCl.sub.2.6H2O; CoSO.sub.4.7H2O; CuCl.sub.2.2H2O; CuSO.sub.4.5H2O; FeCitrat; FeCl.sub.3.6H20; FeSO.sub.4.7H2O; FeTartrat; H2MoO.sub.4.4H2O; H.sub.3BO.sub.3; H.sub.3PO.sub.4; KI; K.sub.2HPO.sub.4; K.sub.2SO.sub.4; KCl; KH.sub.2PO.sub.4; KNO.sub.3; Mg(NO.sub.3).sub.2; MgSO.sub.4.7H2O; MnCl.sub.2.4H2O; MnSO.sub.4.H2O; Na.sub.2MoO.sub.4.2H2O; NaCl; NH.sub.4H.sub.2PO.sub.4; NH.sub.4NO.sub.3; ZnSO.sub.4.7H2O; inorganic (NH.sub.4).sub.2SO.sub.4; Ca(NO.sub.3).sub.2.4H2O; CaCl.sub.2.6H2O; H.sub.3BO.sub.3; H.sub.3PO.sub.4; KCl; K.sub.2SO.sub.4; K.sub.2CO.sub.3; MgSO.sub.4.7H2O; Na.sub.2MoO.sub.4.2H2O; NaCl; NaHCO3; Fe-EDTA; Zn-EDTA; Cu-EDTA, manure; urea; Na2EDTA; Hutner; Hoagland-A; Hoagland-B; Pirson; Hoagland-C; Steinberg; Schenk and Hildebrandt, Murashige, and any combination thereof.

[0110] According to some embodiments, the growth media is controlled and manipulated to achieve predetermined conditions and parameters such as temperature range of the growth media, temperature range of the atmosphere, water content and treatment procedure (such as de-nitrification, mechanical, filtration), illumination intensity, aeration, oxygen concentration, pH and any combination thereof.

[0111] The term Dietary Reference Intake or DRI or recommended daily intake or RDI refers hereinafter to any standard which pertains to the daily intake level of a nutrient that is considered to be sufficient to meet the requirements to sustain healthy individuals. RDI standards may include, in a non-limiting example, Recommended Dietary Allowance (RDA), Estimated Average Requirement (EAR), Adequate Intake (AI) and Upper Intake Level (UL) standards.

[0112] It is herein acknowledged that the vitamin B12 dietary reference intake ranges from 0.4 to about 3 g per day. In specific embodiments, the vitamin B12 dietary reference intake for an adult ranges from about 2 to about 3 g per day according to the US health authorities, and about 1.5 g per day according to the UK health authorities. According to a relatively new study, the DRI should be about 4 to about 7 g per day.

[0113] Reference is now made to Table 1, listing the current RDAs for vitamin B12 in micrograms (mcg). For infants aged 0 to 12 months, the Food and Nutrition Board (FNB) at the Institute of Medicine (IOM) of the National Academies (formerly National Academy of Sciences) established an Adequate Intake (AI) for vitamin B12 that is equivalent to the mean intake of vitamin B12 in healthy, breastfed infants.

TABLE-US-00001 TABLE 1 Recommended Dietary Allowances (RDAs) for Vitamin B12 Age Male Female Pregnancy Lactation 0-6 months* 0.4 mcg 0.4 mcg 7-12 months* 0.5 mcg 0.5 mcg 1-3 years 0.9 mcg 0.9 mcg 4-8 years 1.2 mcg 1.2 mcg 9-13 years 1.8 mcg 1.8 mcg 14+ years 2.4 mcg 2.4 mcg 2.6 mcg 2.8 mc

[0114] It is according to one embodiment of the present invention to disclose a method for producing vitamin B12 enriched Duckweed Bacterial Culture (DBC) composition, wherein the method comprises steps of: (a) inoculating at least one Lemnoideae species and at least one vitamin B12 producing bacteria species in a volume of growth media; (b) incubating the at least one Lemnoideae species and the at least one vitamin B12 producing bacteria species under predetermined conditions to provide a Duckweed-Bacterial Culture (DBC); (c) plotting Lemnoideae plant biomass at the predetermined conditions against time; (d) plotting bacterial count of the at least one B12 producing bacteria species at the predetermined conditions against time; (e) plotting vitamin B12 content in the DBC at the predetermined conditions against time; (f) determining time intervals within the plots characterized by DBC with highest vitamin B12 content; and (g) harvesting the DBC at the predetermined time intervals, thereby providing vitamin B12 enriched DBC composition.

[0115] It is further within the scope to disclose the method as defined in any of the above, wherein the step of incubating additionally comprises steps of selecting the predetermined conditions designed for (i) optimal growth of the at least one Lemnoideae species plant, and (ii) optimal fermentation of the vitamin B12 synthesizing bacteria associated therewith.

[0116] It is further within the scope to disclose the method as defined in any of the above, wherein the step of incubating additionally comprises steps of growing the at least one Lemnoideae species and the at least one vitamin B12 producing bacteria species under predetermined conditions to provide association between the at least one bacterial species and the at least one Lemnoideae species.

[0117] It is further within the scope to disclose the method as defined in any of the above, additionally comprises steps of selecting the association from the group consisting of: symbiotic interaction, persistent mutualism, persistent biological interaction, mutualism, interspecies reciprocal altruism, commensalistic interaction, parasitic symbiosis, obligate interaction, facultative interaction, obligate for both species, obligate for one but facultative for the other, facultative for both species, ectosymbiosis, endosymbiosis, commensal ectosymbiosis, mutualist ectosymbiosis, ectoparasitism, conjunctive symbiosis, disjunctive symbiosis, antagonistic or antipathetic symbiosis or relationship, necrotrophic interaction, biotrophic interaction, amensalism, competition relationship, antibiosis relationship, synnecrosis and any combination thereof.

[0118] It is further within the scope to disclose the method as defined in any of the above, wherein the step of inoculating comprises steps of growing the at least one Lemnoideae species and the at least one B12 producing bacteria species as a batch or as a continuous culture.

[0119] It is further within the scope to disclose the method as defined in any of the above, wherein the step of inoculating comprises steps of selecting the volume of growth media from the group consisting of: an aqueous plant growing facility and a microbial growing facility.

[0120] It is further within the scope to disclose the method as defined in any of the above, wherein the step of inoculating comprises steps of selecting the volume of growth media from the group consisting of: a pool, a channel, an aquarium, a fermenter, a bioreactor, cobbles and any other substrate.

[0121] It is further within the scope to disclose the method as defined in any of the above, wherein the step of incubating additionally comprising steps of selecting the predetermined conditions for growth of the Lemnoideae species biomass from the group consisting of: mineral composition of the growth media, mineral concentration of the growing media, urea concentration, nitrites and nitrates concentration, total ammonia concentration, temperature range of the growing media, temperature range of the atmosphere, water treatment procedure, illumination intensity, aeration, oxygen concentration, pH and any combination thereof.

[0122] It is further within the scope to disclose the method as defined in any of the above, additionally comprising steps of selecting the mineral from the group consisting of: Mg.sup.2+, Mn, Zn, Fe.sup.2+, Zn.sup.2+, Mn.sup.2+, CaCl.sub.2 and any combination thereof.

[0123] It is further within the scope to disclose the method as defined in any of the above, additionally comprising steps of selecting the water treatment procedure from the group consisting of: de-nitrification, mechanical, filtration and any combination thereof.

[0124] It is further within the scope to disclose the method as defined in any of the above, wherein the step of incubating additionally comprising steps of selecting the predetermined conditions for symbiotic fermentation and vitamin B12 synthesis of the bacterial species from the group consisting of: sugar concentration in the range of about 0.01-3.0% w/v, amino acids and/or peptides and/or vitamins sources in a concentration range of about 0.01-3.0% w/v thereof, amino acids or mixes thereof in a concentration range of about 0.0001-0.3 g/l, microelements in a concentration range of about 0.0001-0.3 g/l, vitamins and any combination thereof.

[0125] It is further within the scope to disclose the method as defined in any of the above, additionally comprising steps of selecting the sugar from the group consisting of dextrose, glucose, lactose and any combination thereof.

[0126] It is further within the scope to disclose the method as defined in any of the above, additionally comprising steps of selecting the amino acids and/or peptides and/or vitamins sources from the group consisting of Yeast extract, Enzymatic Digest of Casein, Enzymatic Digest of Gelatin and any combination thereof.

[0127] It is further within the scope to disclose the method as defined in any of the above, additionally comprising steps of selecting the amino acids or mixes thereof from the group consisting of L-ArginineoHCl, L-Cysteine, L-Glutamine, Glycine, L-HistidineoHCloH.sub.2O, L-Isoleucine, L-Leucine, L-LysineoHCl, L-Methionine, L-Phenylalanine, L-Serine, L-Threonine, L-Tryptophan, L-Tyrosine 2Nao2H2O, L-Valine and any combination thereof.

[0128] It is further within the scope to disclose the method as defined in any of the above, additionally comprising steps of selecting the microelements from the group consisting of: Choline Chloride, Folic Acid, myo-Inositol, Niacinamide, D-Pantothenic Acid hemicalcium, Calcium Chloride, Ferric Nitrate, Magnesium Sulfate, Potassium Chloride, Sodium Chloride, Sodium Phosphate and any combination thereof.

[0129] It is further within the scope to disclose the method as defined in any of the above, additionally comprising steps of selecting the bacteria from the group consisting of: Pseudomonas species such as P. aeruginosa, P. florescenza, P. murina, Bacillus species, Methanobacterium species, Propionibacterium species, Acetobacterium, Aerobacter, Agrobacterium, Alcaligenes, Azotobacter, Clostridium, Flavobacterium, Lactobacillus, Micromonospora, Mycobacterium, Nocardia, Propionibacterium, Protaminobacter, Proteus, Pseudomonas, Rhizobium, Salmonella, Serratia, Streptomyces, Streptococcus, Xanthomonas and any combination thereof.

[0130] It is further within the scope to disclose the method as defined in any of the above, wherein the step of determining additionally comprises steps of determining the growth curves of the at least one Lemnoideae species and the at least one B12 producing bacteria species against time and identifying time intervals characterized by highest biomass of the at least one Lemnoideae species and highest bacterial cell count of the at least one bacteria species.

[0131] It is further within the scope to disclose the method as defined in any of the above, additionally comprising steps of selecting the biomass from the group consisting of: whole Lemnoideae biomass, fresh Lemnoideae biomass, dry Lemnoideae biomass and any combination thereof.

[0132] It is further within the scope to disclose the method as defined in any of the above additionally comprising steps of selecting the at least one Lemnoideae species from a species belonging to the genera group consisting of: Landoltia, Lemna, Spirodela, Wolffia, Wolffiella and any combination thereof.

[0133] It is further within the scope to disclose the method as defined in any of the above, additionally comprising steps of selecting the at least one Lemnoideae species from the group consisting of: Wolffia angusta, Wolffia arrhiza, Wolffia australiana, Wolffia borealis, Wolffia brasiliensis, Wolffia Columbiana, Wolffia cylindracea, Wolffia elongate, Wolffia globose, Wolffia microscopica, Wolffia neglecta and any combination thereof.

[0134] It is further within the scope to disclose the method as defined in any of the above, additionally comprises steps of providing vitamin B12 enriched DBC composition comprising between about 0.01 and about 100 g vitamin B12 per 100 g of the DBC.

[0135] The present invention further provides a composition comprising a vitamin B12 enriched Duckweed-Bacterial Culture (DBC), wherein the composition comprises at least one Lemnoideae species and at least one B12 producing bacteria species, further wherein the vitamin B12 content in the composition is in the range of between about 0.01 g and about 100 g per 100 g of the DBC.

[0136] It is according to one embodiment to disclose the composition as defined in any of the above, wherein the vitamin B12 content in the composition is a predetermined percentage of at least 20% of the vitamin B12 recommended Daily Value (DV).

[0137] It is according to another embodiment to disclose the composition as defined in any of the above, wherein the vitamin B12 content in the composition complies with the vitamin B12 recommended daily intake (RDI) standard for an adult ranging from about 0.4 g to about 3 g per day.

[0138] It is according to another embodiment to disclose the composition as defined in any of the above, wherein the at least one B12 producing bacteria species is in association with the at least one Lemnoideae species.

[0139] It is according to another embodiment to disclose the composition as defined in any of the above, wherein the association is selected from the group consisting of: symbiotic interaction, persistent mutualism, persistent biological interaction, mutualism, interspecies reciprocal altruism, commensalistic interaction, parasitic symbiosis, obligate interaction, facultative interaction, obligate for both species, obligate for one but facultative for the other, facultative for both species, ectosymbiosis, endosymbiosis, commensal ectosymbiosis, mutualist ectosymbiosis, ectoparasitism, conjunctive symbiosis, disjunctive symbiosis, antagonistic or antipathetic symbiosis or relationship, necrotrophic interaction, biotrophic interaction, amensalism, competition relationship, antibiosis relationship, synnecrosis and any combination thereof.

[0140] It is according to another embodiment to disclose the composition as defined in any of the above, wherein the B12 producing bacteria are selected from the group consisting of: Pseudomonas species such as P. aeruginosa, P. florescenza, P. murina, Bacillus species, Methanobacterium species, Propionibacterium species, Acetobacterium, Aerobacter, Agrobacterium, Alcaligenes, Azotobacter, Clostridium, Flavobacterium, Lactobacillus, Micromonospora, Mycobacterium, Nocardia, Propionibacterium, Protaminobacter, Proteus, Pseudomonas, Rhizobium, Salmonella, Serratia, Streptomyces, Streptococcus, Xanthomonas and any combination thereof.

[0141] It is according to another embodiment to disclose the composition as defined in any of the above, wherein the at least one Lemnoideae species is selected from the group consisting of: whole Lemnoideae biomass, fresh Lemnoideae biomass, dry Lemnoideae biomass and any combination thereof.

[0142] It is according to another embodiment to disclose the composition as defined in any of the above, wherein the at least one Lemnoideae species belongs to a genera selected from the group consisting of: Landoltia, Lemna, Spirodela, Wolffia, Wolffiella and any combination thereof.

[0143] It is according to another embodiment to disclose the composition as defined in any of the above, wherein the at least one Lemnoideae species is selected from the group consisting of: Wolffia angusta, Wolffia arrhiza, Wolffia australiana, Wolffia borealis, Wolffia brasiliensis, Wolffia Columbiana, Wolffia cylindracea, Wolffia elongate, Wolffia globose, Wolffia microscopica, Wolffia neglecta and any combination thereof.

[0144] It is further within the scope to disclose a composition comprising vitamin B12 enriched Duckweed Bacterial Culture (DBC) produced by the method as defined in any of the above.

[0145] It is further within the scope to disclose the composition produced by the method as defined in any of the above, wherein the predetermined conditions are selected from the group consisting of conditions for growth of the Lemnoideae species biomass, conditions for fermentation and vitamin B12 synthesis of the bacterial species and a combination thereof.

[0146] It is further within the scope to disclose the composition produced by the method as defined in any of the above, wherein the volume of growth media is a batch or a continuous culture.

[0147] It is further within the scope to disclose the composition produced by the method as defined in any of the above, wherein the volume of growth media is selected from the group consisting of: an aqueous plant growing facility and a microbial growing facility.

[0148] It is further within the scope to disclose the composition produced by the method as defined in any of the above, wherein the volume of growth media is selected from the group consisting of: a pool, a channel, an aquarium, a fermenter, a bioreactor, cobbles and any other substrate.

[0149] It is further within the scope to disclose the composition produced by the method as defined in any of the above, wherein the predetermined conditions for growth of the Lemnoideae species biomass are selected from the group consisting of: mineral composition of the growing media, mineral concentration of the growing media, urea concentration, nitrites and nitrates concentration, total ammonia concentration, temperature range of the growing media, temperature range of the atmosphere, water treatment procedure, illumination intensity, aeration, oxygen concentration, pH and any combination thereof.

[0150] It is further within the scope to disclose the composition produced by the method as defined in any of the above, wherein the mineral is selected from the group consisting of: Mg.sup.2+, Mn, Zn, Fe.sup.2+, Zn.sup.2+, Mn.sup.2+, CaCl.sub.2 and any combination thereof.

[0151] It is further within the scope to disclose the composition produced by the method as defined in any of the above, wherein the water treatment procedure is selected from the group consisting of: de-nitrification, mechanical, filtration and any combination thereof.

[0152] It is further within the scope to disclose the composition produced by the method as defined in any of the above, wherein the predetermined conditions for fermentation and vitamin B12 synthesis of the bacterial species are selected from the group consisting of: sugar concentration in the range of about 0.01-3.0% w/v, amino acids and/or peptides and/or vitamins sources in a concentration range of about 0.01-3.0% w/v thereof, amino acids or mixes thereof in a concentration range of about 0.0001-0.3 g/l, microelements in a concentration range of about 0.0001-0.3 g/l, vitamins and any combination thereof.

[0153] It is further within the scope to disclose the composition produced by the method as defined in any of the above, wherein the sugars are selected from the group consisting of dextrose, glucose, lactose and any combination thereof.

[0154] It is further within the scope to disclose the composition produced by the method as defined in any of the above, wherein the amino acids and/or peptides and/or vitamins sources are selected from the group consisting of Yeast extract, Enzymatic Digest of Casein, Enzymatic Digest of Gelatin and any combination thereof.

[0155] It is further within the scope to disclose the composition produced by the method as defined in any of the above, wherein the amino acids or mixes thereof are selected from the group consisting of L-ArginineoHCl, L-Cysteine, L-Glutamine, Glycine, L-HistidineoHCloH.sub.2O, L-Isoleucine, L-Leucine, L-LysineoHCl, L-Methionine, L-Phenylalanine, L-Serine, L-Threonine, L-Tryptophan, L-Tyrosine 2Nao2H2O, L-Valine and any combination thereof.

[0156] It is further within the scope to disclose the composition produced by the method as defined in any of the above, wherein the microelements are selected from the group consisting of: Choline Chloride, Folic Acid, myo-Inositol, Niacinamide, D-Pantothenic Acid hemicalcium, Calcium Chloride, Ferric Nitrate, Magnesium Sulfate, Potassium Chloride, Sodium Chloride, Sodium Phosphate and any combination thereof.

[0157] It is further within the scope of the present invention to disclose a system for producing vitamin B12 enriched Duckweed Bacterial Culture (DBC) composition, wherein the system comprises: (a) at least one inoculum of Lemnoideae species and at least one inoculum of vitamin B12 producing bacteria species for cultivation in a volume of growth media; (b) an incubation means for incubating the at least one Lemnoideae species inoculum and the at least one vitamin B12 producing bacteria species inoculum under predetermined conditions to provide a Duckweed-Bacterial Culture (DBC); (c) means for determining time intervals within the plots characterized by DBC with highest vitamin B12 content; and (d) means for harvesting the DBC at the predetermined time intervals, thereby providing vitamin B12 enriched DBC composition.

[0158] It is further within the scope of the present invention to disclose the system as defined above, wherein the system additionally comprises at least one plotting means selected from the group consisting of: (a) plotting means for plotting Lemnoideae plant biomass at the predetermined conditions against time; (b) plotting means for plotting bacterial count of the at least one B12 producing bacteria species at the predetermined conditions against time; and (c) plotting means for plotting vitamin B12 content in the DBC at the predetermined conditions against time.

[0159] It is further within the scope of the present invention to disclose a composition comprising a vitamin B12 enriched extract of at least one Lemnoideae species and at least one B12 producing bacteria species, further wherein the vitamin B12 content in the composition is in the range of between about 0.01 and about 100 g per 100 g of the DBC.

[0160] Reference is now made to FIG. 1, illustrating a typical bacterial growth curve or kinetic curve as known in the prior art. This curve generally describes the phases of bacterial growth versus time, after inoculating the bacteria into a selected growth medium. As can be seen, the first stage in the growth curve is a period of adaptation, called the lag phase. During the lag phase, bacteria adapt themselves to growth conditions. It is the period where the individual bacteria are maturing and not yet able to divide. During the lag phase of the bacterial growth cycle, synthesis of RNA, enzymes and other molecules occurs.

[0161] Following the lag phase, the rate of growth of the organism steadily increases; this period is the log or exponential phase. The log phase is a period characterized by cell duplication. The duplication rate is proportional to the particular population. If growth is not limited, doubling will continue at a constant rate so both the number of cells and the rate of population increase doubles with each consecutive time period. For this type of exponential growth, plotting the natural logarithm of cell number against time, produces a straight line. The slope of this line is the specific growth rate of the organism, which is a measure of the number of divisions per cell per unit time. The actual rate of this growth (i.e. the slope of the line in the figure) depends upon the growth conditions, which affect the frequency of cell division events and the probability of both daughter cells surviving. Exponential growth cannot continue indefinitely, because the medium is depleted of nutrients and enriched with wastes.

[0162] Thus, after a certain time of exponential phase, the rate of growth slows down, due to the continuously falling concentrations of nutrients and/or continuously increasing (accumulating) concentrations of toxic substances. This phase, where the growth increase ceases is called a stationary phase or a steady state. The biomass remains constant, except when certain accumulated chemicals in the culture lyse the cells (chemolysis). Thus, the stationary phase is often due to a growth-limiting factor such as the depletion of an essential nutrient, and/or the formation of an inhibitory product such as an organic acid. Stationary phase results from a situation in which growth rate and death rate are equal. The number of new cells created is limited by the growth factor and as a result the rate of cell growth matches the rate of cell death. The result is a horizontal linear part of the curve during the stationary phase.

[0163] Unless other micro-organisms contaminate the culture, the chemical constitution remains unchanged. When all of the nutrients in the medium are consumed, or if the concentration of toxins is too high, the cells may become senescent and begin to die. In this death phase, the total amount of biomass may not decrease, but the number of viable organisms will decrease. At death phase, (Decline phase) bacteria die. This could be due to lack of nutrients, a temperature which is too high or low etc.

[0164] It is according to a main aspect of the invention that time intervals of high bacterial vitamin B12 concentration have been identified in accordance with the bacterial growth curve exemplified in FIG. 1. It can be seen that a time period of higher vitamin B12 concentration is identified at the interval between the exponential phase and the stationary phase, where the growth rate slows, due to the continuously falling concentrations of nutrients and/or continuously increasing (accumulating) concentrations of toxic substances. At this interval, the increase of the growth rate is checked. Another period or time interval of higher vitamin B12 concentration is identified between the end of the stationary phase and before the beginning of the death phase.

[0165] Reference is now made to FIG. 2, illustrating an exemplified duckweed-bacteria culture (DBC) growth curve or profile, as an embodiment of the present invention. It is within the scope of the present invention that at least one Lemnoideae species and at least one vitamin B12 producing bacteria species are grown under predetermined conditions for (i) maximal effective growth of said Lemnoideae species biomass, and (ii) maximal and effective fermentation and vitamin B12 synthesis of said bacterial species. As shown in this figure, time intervals or time frames of maximal B12 production and duckweed biomass are identified. These time intervals are characterized by maximal DBC B12 production. In other words, at these time intervals, DBC with enriched vitamin B12 concentration is harvested. This highly nutritional vitamin B12 source may be used as fresh or dry material characterized by high concentrations of natural vitamin B12 for human consumption.

[0166] In some embodiments of the invention, the vitamin B12 content in said DBC is a predetermined percentage of the vitamin B12 Dietary Reference Intakes (DRIs) standard.

[0167] In other embodiments of the invention, the vitamin B12 content in said DBC is a predetermined percentage of the Daily Value (DV) of vitamin B12.

[0168] It is herein acknowledged that intake recommendations for vitamin B12 and other nutrients are provided in the Dietary Reference Intakes (DRIs) developed by the Food and Nutrition Board (FNB) at the Institute of Medicine (IOM) of the National Academies. The term DRI is herein generally refers to a set of reference values used for planning and assessing nutrient intakes of healthy people. These values, which vary by age and gender, include:

[0169] Recommended Dietary Allowance (RDA), defined as the average daily level of intake sufficient to meet the nutrient requirements of nearly all (97%-98%) healthy individuals.

[0170] Adequate Intake (AI) established when evidence is insufficient to develop an RDA and is set at a level assumed to ensure nutritional adequacy.

[0171] Tolerable Upper Intake Level (UL), which is defined as the maximum daily intake unlikely to cause adverse health effects.

[0172] It is further acknowledged that the dietary reference intake (DRI) of vitamin B12 for an adult ranges from 0.4 to 3 g per day in the US and 1.5 g per day in the UK. But according to recent studies, the DRI should be between 4 to 7 g per day. It is noted that the Center for Food Safety and Applied Nutrition recommends 6 g per day, based on a caloric intake of 2,000 calories, for adults and children four or more years of age.

[0173] It is further noted that vitamin B12 is believed to be safe when used orally in amounts that do not exceed the recommended dietary allowance (RDA).

[0174] According to some aspects, the vitamin B12 recommended dietary amounts (RDAs) are 2.4 micrograms daily for ages 14 years and older, 2.6 micrograms daily for pregnant females, and 2.8 micrograms daily for breastfeeding females. Adults over 50 years of age should meet the RDA by eating foods reinforced with B12 or by taking a vitamin B12 supplement. It was reported that supplementation of 25-100 micrograms daily has been used to maintain vitamin B12 levels in older people.

[0175] Reference is now made to Daily Value (DV) of vitamin B12. It is herein acknowledged that DVs were developed by the U.S. Food and Drug Administration (FDA) to help consumers determine the level of various nutrients in a standard serving of food in relation to their approximate requirement for it. The DV for vitamin B12 is 6.0 mcg. However, the FDA does not require food labels to list vitamin B12 content unless a food has been fortified with this nutrient. Foods providing 20% or more of the DV are considered to be high or enriched sources of a nutrient, but foods providing lower percentages of the DV also contribute to a healthful diet.

[0176] The present invention provides means and methods for producing a vitamin B12 enriched duckweed biomass composition comprising at least one Lemnoideae species and at least one vitamin B12 producing bacteria species, which produce Duckweed-Bacterial Culture (DBC) in predesigned conditions. The vitamin B12 enriched composition can be consumed by intake of a predetermined dosage of said composition, one or more times per day so as to meet the recommended vitamin B12 Dietary Reference Intake (DRI) of between about 0.4 mcg and about 3 mcg per day.

[0177] According to certain aspects, the composition of the present invention provides 20% or more of the vitamin B12 DV and thus is considered to be high or enriched source of this important nutrient.

[0178] According to other aspects, the composition of the present invention comprises between about 0.01 and about 100 g vitamin B12 per 100 g of said DBC.

[0179] As discussed above, it is within the scope that the vitamin B12 enriched composition is preferably provided as dry material to achieve high concentrations of vitamin B12 in a single dose of the composition.