PROCESS FOR REDUCING BIOCHEMICAL OXYGEN DEMAND OF FOOD AND BEVERAGE PROCESSING EFFLUENT
20200165643 ยท 2020-05-28
Inventors
Cpc classification
C02F2103/327
CHEMISTRY; METALLURGY
C02F11/04
CHEMISTRY; METALLURGY
C12P7/40
CHEMISTRY; METALLURGY
C02F3/348
CHEMISTRY; METALLURGY
Y02W10/10
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
C12P17/06
CHEMISTRY; METALLURGY
Y02E50/30
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
International classification
C02F11/04
CHEMISTRY; METALLURGY
C12P7/40
CHEMISTRY; METALLURGY
Abstract
A process and system for reducing biochemical oxygen demand (BOD) of food and beverage processing effluents.
Claims
1. A process for reducing biochemical oxygen demand (BOD) of a food or beverage processing effluent with a BOD greater than 750 mg/L comprising: (i) contacting the process effluent with one or more microorganisms that have been genetically engineered to produce secondary metabolites wherein the secondary metabolites are selected from the group consisting of terpenoids, cannabinoids, cannabinoid producing enzymes, alkaloids or combinations thereof; (ii) allowing the process effluent and microorganisms to react or ferment creating a reaction mass comprising the process effluent with a BOD less than 500 mg/L, the microorganisms and the secondary metabolites; and (iii) removing the secondary metabolites from the reaction mass.
2. The process according to claim 1 wherein the process effluent is whey or whey permeate.
3. The process according to claim 1 wherein the microorganisms have been genetically engineered to produce a cannabinoid.
4. The process according to claim 1 wherein the secondary metabolites are removed with a supercritical CO.sub.2 extraction using CO.sub.2 obtained from step (ii).
5. The process according to claim 3 wherein hexanoic acid is added to step (ii).
6. The process according to claim 5 wherein the hexanoic acid is obtained from a process wherein a first a food or beverage processing effluent with a BOD greater than 750 mg/L is contacted with a genetically engineered microorganism that has been engineered to produce hexanoic acid.
7. The process according to claim 1 further comprising the step of separating the process effluent with a BOD less than 500 mg/L from the reaction mass.
8. The process according to claim 1 further comprising the step of separating the microorganisms from the reaction mass to create a biomass.
9. The process according to claim 8 comprising the steps of treating the biomass to anaerobic digestion to create a biogas and capturing the biogas to supply energy to the process equipment.
Description
BRIEF DESCRIPTION OF THE DRAWING
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DETAILED DESCRIPTION OF THE INVENTION
[0031] Before the present invention is further described, it is to be understood that this invention is not limited to the particular embodiments described. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.
[0032] It should be noted that as used herein, the singular forms a, an, and the include plural referents unless the context clearly dictates otherwise.
[0033] Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges, and are also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the invention.
[0034] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, the preferred methods and materials are now described. All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and/or materials in connection with which the publications are cited.
[0035] As used herein the term food and beverage processing effluent and processing effluent and effluent may be used interchangeably unless specifically indicated to the contrary. These terms encompass a liquid by-product or co-product generated during the manufacturing or processing of a food or beverage. In certain aspects of the invention, the food and beverage processing effluent with a high BOD concentration will exhibit a BOD of greater than 750 mg/L, greater than 1,000 mg/L greater than 2,500 mg/L, greater than 5,000 nm/L, greater than 7,500 mg/L, greater than 10,000 mg/L; greater than 12,500 mg/L, greater than 15,000 mg/L, greater than 17,500 mg/L, greater than 20,000 mg/L and greater than 25,000 mg/L. The processes and systems of the present invention should reduce the BOD of the processing effluent by at least 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% or 95% or more. In certain embodiments the processed effluent discharged from the process and systems of the present invention should have a BOD concentration of less than 500 mg/L, less than 400 mg/L, less than 300 mg/L, less than 200 mg/L or less than 100 mg/L.
[0036] As used herein the term whey refers a liquid by-product or co-product generate during the production of cheese and dairy products. Unless specifically stated, whey includes all types and classifications of why including sweet whey and acid whey. The term whey permeate includes whey that has been filtered or processed to remove specific components, typically proteins and fat.
[0037] As used herein the term secondary metabolite refers to one or more of the products produced when a microorganism such as a bacteria, cyanobacteris, filamentous fungi, algae or yeast contacts a carbon source, particularly a sugar such as dextrose, fructose, glactose, glucose, lactose, maltose, sucrose, xylose etc. and the microorganism metabolizes the carbon source, particularly a sugar, into new compounds such as terpenoids, cannabinoids, cannabinoid producing enzymes and alkaloids. This process is sometime referred to as fermentative production. Secondary metabolites do not include the well-known fermentative production products such as CO.sub.2 and ethanol although these well-known fermentative products may also be produced during the production of the desired or target secondary metabolites of the present invention.
[0038] The term reaction mass is used to described the contents of a reaction vessel and may include process effluent, microorganisms for reacting with or fermenting the process effluent, and any other materials such a pH adjusting agents, or incubation materials need to assist in the growth and propagation of the microorganisms. The reaction mass may also include the well-known metabolites of the fermentation process and the secondary metabolites. The term biomass as used herein refers to material produced by microorganisms as well as the microorganisms, essentially the solids of the fermentation process. Biomass can contain cells, microbes, viruses and/or intracellular contents as well as extracellular material including, for example, compounds that are secreted by a cell, such as secreted secondary metabolites. The biomass may be part of the reaction mass.
[0039] The genetically engineered microorganisms that produce the desired or target secondary metabolites of the present invention are known in the art or can be prepared a person of ordinary skill in the art of microbial engineering using known techniques. Some examples of the genetically engineered microorganisms that can be used in the present invention are described in U.S. Pat. No. 9,822,384 which describes genetically engineered microorganisms that can produce cannabinoids including genetically modified S. cerevisiae and K. marxianus; U.S. Patent Application Publication No. 2017/0233778 which describes genetically engineered microorganisms that can produce cannabinoid producing enzymes including genetically modified Pichia Pastoris; U.S. Patent Application Publication Nos. 2018/0080035 and 2018/014697 which describe genetically engineered microorganisms that can produce terpenoids; U.S. Patent Application Publication No. 2018/0334692 which describes genetically engineered microorganisms that can produce cannabinoid producing enzymes and cannabinoids; International Patent Application Publication Nos. WO 2017/139496 and WO 2019/014490 which describe genetically engineered microorganisms that can produce cannabinoid producing enzymes, cannabinoid precursor such as hexanoic acid and olivetolic acid and cannabinoids; Luo X, et. al., Complete Biosynthesis of Cannabinoids and Their Unnatural Analogues in Yeast, Nature, March 2019; 567(7746):123-6 (http://www.nature.com/articles/s41586-019-0978-9) which describes genetically engineered microorganisms that can produce cannabinoid producing enzymes, cannabinoid precursor and cannabinoids; Cheon Y, e.t al., A Biosynthetic Pathway for Hexanoic Acid Production in Kluyveromyces Marxianus, J Biotechnol, July 2014 63(3): 223-24 (http://www.ncbi.nlm.nih.gov/pubmed/24768798) which describe genetically engineered microorganisms that can produce hexanoic acid; Yang J, et. al., Metabolic Engineering of Escherichia Coli for the Biosynthesis of Alpha-Pinene, Biotechnol Biofuels, April 2013; 6(1):60 (http://biotechnologyforbiofuels.biomedcentral.com/articles/10.1186/1754-6834-6-60) which describe genetically engineered microorganisms that can produce -pinene; Ehrenworth A M, et. al., Accelerating the Semisynthesis of Alkaloid-Based Drugs Through Metabolic Engineering, Nat Chem Biol., March 2017; 13 (3): 249-58 (http://www.nature.com/articles/nchembio 0.2308) which describes genetically engineerd microoganisms that can produce the N-demethylnarwedine which can be converted to the alkaloid galantamine; Zhuang et al., Monoterpene Production by the Carotenogenic Yeast Rhodosporidium Toruloides, Microbial Cell Factories 2019; 18(1):1-(https://microbialcellfactories.biomedcentral.com/track/pdf/10.1186/s12934-019-1099-8) which describes microorganisms which produce terpenoids; Kang et. al., Biosynthesis of Pinene From Glucose Using Metabolically-Engineered Corynebacterium Glutamicum, Biotechnol. Lett. 2014, 36:2069-2077 which describes the production of terpenoids; Xie et, al., Mining Terpenoids Production and Biosynthetic Pathway in Thraustochytrids Bioresource Technology 2017; 244: 1269-1280; which describes the microalgae/protists production of terpenes. The contents of the foregoing patents, patent applications and publications are incorporated herein by reference.
[0040] The reaction or fermentation of the processing effluent with a high BOD concentration and genetically engineered microorganisms may occur in an appropriate reaction vessel or bioreactor. In some embodiments, the genetically engineered microorganism can be added to the reaction vessel or bioreactor as spores and/or any kind of dormant cell type of any isolated microorganism described herein, for example, in a dry state. In some embodiments, the addition of the process effluent to the reaction vessel can lead to activation of the dormant cells, for example, to the germination of a yeast spore, and subsequent conversion of the sugar source in the process effluent to one or more of the desired or targeted secondary metabolites such as a cannabinoid, cannabinoid precursor or a cannabinoid producing enzyme. In some embodiments, the genetically engineered microorganisms are activated prior to the addition of the processing effluent with the high BOD concentration. The prior activation of the genetically engineered microorganisms may occur in the reaction vessel wherein the reaction or fermentation process occurs or alternatively the prior activation may in a separate reaction vessel prior to the addition to the reaction vessel wherein the reaction or fermentation process occurs.
[0041] In some embodiments, the genetically engineered microorganisms described are contacted with the aqueous process effluent such as whey or whey permeate in a bioreactor, and the generated/secreted fermentation products including the secondary metabolites, form an organic phase that can be separated from the aqueous phase. The term organic phase can refer to a liquid phase comprising a non-polar, organic compound, including, for example, a cannabinoid, a cannabinoid precursor, and/or a non-polar lipid. An organic phase described herein can further contain microorganisms or other compounds also found in aqueous phase.
[0042] Methods useful for removing or separating the organic phase and/or secondary metabolites from the reaction mass are well known to those of ordinary skill in the art. In some embodiments, the organic phase is continuously or semi-continuously siphoned off. In some embodiments, a reaction vessel or bioreactor can comprise a separator that can be used, to continuously or semi-continuously extract the organic phase from the inorganic phase. In certain embodiments the separation employs supercritical CO.sub.2 extraction, preferably a counter current supercritical CO.sub.2 extraction step wherein at least a portion of the CO.sub.2 used in the supercritical CO.sub.2 extraction has been obtained from the CO.sub.2 generated by the reaction of the genetically engineered microorganisms and the process effluent with the high BOD concentration or generated by an earlier reaction/batch of the genetically engineered microorganisms and the process effluent with the high BOD concentration.
[0043] In some embodiments, the desired or target secondary metabolites of the present invention can accumulate in a cell according to aspects described herein. In some embodiments, a cell that accumulates a desirable amount of the desired or target secondary metabolites can be separated continuously or semi-continuously from a bioreactor. Non-limiting chemical separation methods include centrifugation, sedimentation, and filtration. Cell separation can further be affected based on a change in physical cell characteristic, such as cell size and cell density, by methods well known to those skilled in the art. The accumulated desired or target secondary metabolites can subsequently be extracted from the respective cells using standard methods of extraction well known to those skilled in the art. Non-limiting extraction methods include liquid-liquid solvent extraction. Additional non-limiting examples of cell extraction methods include the application of enzymes, detergents, heat, pressure, and mechanical action some of which are described in WO 2017/139496 which are incorporated herein by reference. In some embodiments, the extracted desired or target secondary metabolite can be further refined using additional purification methods well known in the art such as fractional distillation, crystallization, solvent extractions, salt formation or chromatographic techniques.
[0044] Typically the genetically engineered microorganisms used in the present invention are grown at a temperature in the range of about 25 C. to about 70 C., preferably about 25 C. to about 40 C. in an appropriate medium. Suitable growth media that may be used in the present invention are common commercially prepared media such as Luria Bertani (LB) broth, M9 minimal media, Sabouraud Dextrose (SD) broth, Yeast medium (YM) broth, (Ymin) yeast synthetic minimal media, and minimal media as described herein, such as M9 minimal media. Other defined or synthetic growth media may also be used, and the appropriate medium for growth of the particular microorganism will be known by one skilled in the art of microbiology or bio-production science. In various embodiments a minimal media may be developed and used that does not comprise, or that has a low level of addition of various components, for example less than 10, 5, 2 or 1 g/L of a complex nitrogen source including but not limited to yeast extract, peptone, tryptone, soy flour, corn steep liquor, or casein. These minimal medias may also have limited supplementation of vitamin mixtures including biotin, vitamin B12 and derivatives of vitamin B12, thiamin, pantothenate and other vitamins. Minimal medias may also have limited simple inorganic nutrient sources containing less than 28, 17, or 2.5 mM phosphate, less than 25 or 4 mM sulfate, and less than 130 or 50 mM total nitrogen. The foregoing temperatures and additional growth media nutrients may be employed during the reaction or fermentation of the high BOD concentration processing effluent with the genetically modified microorganisms, or in the activation and/or propagation of the genetically engineered microorganisms prior to contact with the process effluent with a high BOD concentration.
[0045] Suitable pH ranges for the reaction or fermentation of the high BOD concentration processing effluent with the genetically modified microorganisms are between pH 3.0 to pH 10.0, preferably between a pH 5.0 to pH 8.0 is a typical pH range for the initial condition. However, the actual culture conditions for a particular embodiment are not meant to be limited by these pH ranges.
[0046] The reaction or fermentation of the high BOD concentration processing effluent with the genetically modified microorganisms may be performed under aerobic, microaerobic, or anaerobic conditions, with or without agitation.
[0047] The various embodiments of the present invention may employ a batch type reaction vessel or bioreactor. A classical batch bioreactor system is considered closed meaning that the composition of the medium is established at the beginning of a respective bio-production event and not subject to artificial alterations and additions during the time period ending substantially with the end of the bio-production event. Thus, at the beginning of the bio-production event the process effluent with high BOD concentration is inoculated with the desired genetically engineered microorganisms, and bio-production is permitted to occur without adding anything to the system. In batch systems the metabolite and biomass compositions of the system change constantly up to the time the bio-production event is stopped, typically when the desired BOD concentration is obtained. Within batch cultures cells moderate through a static lag phase to a high growth log phase and finally to a stationary phase where growth rate is diminished or halted. If untreated, cells in the stationary phase will eventually die as the sugars in the process effluent are depleted.
[0048] A variation on the standard batch system may also be used in embodiments of the present invention wherein additional process effluent with a high BOD concentration is added to the reaction at predetermined times or when predetermined levels of BOD or sugars are obtained in the reaction vessel. Batch and fed-batch approaches are common and well known in the art and examples may be found in Thomas D. Brock in Biotechnology: A Textbook of Industrial Microbiology, Second Edition (1989) Sinauer Associates, Inc., Sunderland, Mass., Deshpande, Mukund V., Appl. Biochem. Biotechnol., 36:227, (1992), and Biochemical Engineering Fundamentals, 2.sup.nd Ed. J. E. Bailey and D. F. Ollis, McGraw Hill, New York, 1986, herein incorporated by reference for general instruction on bio-production.
[0049] Although embodiments of the present invention may be performed in batch mode, or in fed-batch mode, it is contemplated that the invention would be adaptable to continuous bio-production methods. Continuous bio-production is considered an open system where a defined amount of the process effluent with the high BOD concentration is added continuously to a bioreactor and an equal amount of conditioned media is removed simultaneously for processing. Continuous bio-production generally maintains the cultures within a controlled density range where cells are primarily in log phase growth. Continuous bio-production is particularly advantageous for because it has less down time associated with draining, cleaning and preparing the equipment for the next bio-production event. Furthermore, it is typically more economical to continuously operate downstream unit operations, such as distillation, than to run them in batch mode.
[0050] The various embodiments of the present invention comprise a system for reducing the BOD concentration of process effluent and particularly whey and whey permeates comprising: a fermentation tank suitable for microorganism cell culture; a line for discharging contents from the fermentation tank to an extraction and/or separation vessel; and an extraction and/or separation vessel suitable for removal of the desired or target secondary metabolites from cell culture waste. In various embodiments, the system may include one or more pre-fermentation tanks, distillation columns, centrifuge vessels, back extraction columns, mixing vessels, or combinations thereof.
[0051] The present invention will be further described by reference to
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[0054] As shown in
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[0057] As shown in
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[0060] The anaerobic digestion can be added to the processes and systems described in
[0061] The processes and systems of the present invention may be further modified. For example, the process effluent with the high BOD concentration may be pretreated prior to incorporation in the bioreactors with the genetically engineered microorganisms. Such pretreatment may comprise adjusting the pH to an acceptable or optimal level for microbial growth. Similarly, the temperature of the process effluent with the high BOD concentration may be adjusted to a temperature for acceptable or optimal level for microbial growth. In certain embodiments, when the process effluent comprises a large amount of lactose such as whey or whey permeate, the process effluent may be pretreated with microorganisms or enzymes such as -galactosidases that cleave lactose into glucose and galactose prior to the addition of the genetically engineered microorganisms that produce the desired or target secondary metabolites selected from the group consisting of terpenoids, cannabinoids, cannabinoid producing enzymes, alkaloids or combinations thereof. This pretreatment to cleave lactose will allow genetically engineered microorganisms such as Saccharomyces cerevisiae to be used to produce secondary metabolites from high lactose containing process effluents such as whey and whey permeate.
[0062] The invention illustratively described herein suitably may be practiced in the absence of any element or elements, limitation or limitations which is not specifically disclosed herein. Thus, for example, in each instance herein, any of the terms comprising, consisting essentially of and consisting of may be replaced with either of the other two terms. The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention as defined by the appended claims.