The present invention relates to the field of microbial production of novel biosurfactants. More specifically, the present invention discloses the usage of a fungal strain such as the yeast Starmerella bombicola having a dysfunctional CYP52M1 cytochrome P450 monooxygenase and a dysfunctional FAO1 fatty alcohol oxidase for producing high amounts of so-called symmetrical bolaform sophorosides where both sophorose moieties are attached through a terminal glycosidic linkage to the hydrophobic linker. In addition, the present invention further discloses that the latter yeast can also be used to produce alkyl sophorosides and symmetrical bolaform glucosides.

The present invention is in the technical field of synthetic biology and metabolic engineering. More particularly, the present invention is in the technical field of metabolically engineered cells and use of said cells in a cultivation, preferably fermentation. The present invention describes a metabolically engineered cell and a method by cultivation, preferably fermentation, with said cell for production of a bioproduct. More specifically, the present invention describes a metabolically engineered cell and a method by cultivation, preferably fermentation, with said cell for production of an N-acetylneuraminic acid (Neu(n)Ac)-containing compound, wherein (n) is 4, 5, 7, 8 or 9 or a combination thereof. The metabolically engineered cell comprises a pathway for production of said Neu(n)Ac-containing compound and is modified in the expression or activity of at least one NeuNAc synthase according to the present invention. Furthermore, the present invention provides for purification of said Neu(n)Ac-containing compound from the cultivation.

The present invention relates to a method for producing 2-O-glyceryl--D-glucopyranoside (GG; FIG. 1) from a glucosyl donor and a glucosyl acceptor comprising the steps: providing a sucrose phosphorylase (EC 2.4.1.7), incubating said sucrose phosphorylase with a mixture comprising a glucosyl donor and glycerol as glucosyl acceptor and isolating and/or purifying 2-O-glyceryl--D-glucopyranoside.

The present invention relates to a method for producing 2-O-glyceryl--D-glucopyranoside (GG; FIG. 1) from a glucosyl donor and a glucosyl acceptor comprising the steps: providing a sucrose phosphorylase (EC 2.4.1.7), incubating said sucrose phosphorylase with a mixture comprising a glucosyl donor and glycerol as glucosyl acceptor and isolating and/or purifying 2-O-glyceryl--D-glucopyranoside.

The present invention relates to a method for producing a glycosylated synthon or a monomer. Said method includes at least one step of placing at least one glycan-saccharase in the presence of at least one hydroxylated synthon and at least one saccharose. The invention also relates to a method for producing a glyco(co)polymer, including polymerizing at least two monomers separately obtained from the enzymatic glycosylation method according to the invention, and to a method for producing a glyco(co)polymer, preferably a block glyco(co)polymer, including coupling at least two monomers separately obtained from the enzymatic glycosylation method according to the invention.

The invention relates to a method for decreasing foam formation as well as maximizing expression of a biosurfactant in a microorganism. The methods encompasses precipitating a biosurfactant from the microorganism which results in decreased form formation.

The invention relates to a method for decreasing foam formation as well as maximizing expression of a biosurfactant in a microorganism. The methods encompasses precipitating a biosurfactant from the microorganism which results in decreased form formation.

There is provided a method of oxidising at least one organic substance in aerobic conditions to produce at least one alcohol, amine, acid, aldehyde, and/or ketone, the method comprising: (a) producing ethanol and/or acetate from a carbon source in aerobic conditions, comprising (i) contacting the carbon source with a reaction mixture comprising a first acetogenic microorganism in an exponential growth phase; free oxygen; and a second acetogenic microorganism in a stationary phase, wherein the first and second acetogenic microorganism is capable of converting the carbon source to the acetate and/or ethanol; and (b) contacting the acetate and/or ethanol from step (a) with the organic substance and with a third microorganism capable of oxidising the organic substance to produce the alcohol, amine, acid, aldehyde, and/or ketone and wherein the acetate is a co-substrate.

There is provided a method of oxidising at least one organic substance in aerobic conditions to produce at least one alcohol, amine, acid, aldehyde, and/or ketone, the method comprising: (a) producing ethanol and/or acetate from a carbon source in aerobic conditions, comprising (i) contacting the carbon source with a reaction mixture comprising a first acetogenic microorganism in an exponential growth phase; free oxygen; and a second acetogenic microorganism in a stationary phase, wherein the first and second acetogenic microorganism is capable of converting the carbon source to the acetate and/or ethanol; and (b) contacting the acetate and/or ethanol from step (a) with the organic substance and with a third microorganism capable of oxidising the organic substance to produce the alcohol, amine, acid, aldehyde, and/or ketone and wherein the acetate is a co-substrate.

The invention provides novel carbohydrate esters, in particular disaccharide esters, and the methods of their preparation. These compounds find use as microbial media components for the induction of gene expression in microbial fermentation processes.