The present invention relates to a method for producing C4 bodies, preferably butyric acid and/or butanol, comprising the steps contacting an aqueous medium comprising an acetogenic bacterial cell in an aqueous medium with syngas and incubating the mixture obtained in step a) at a temperature between 0 and 100° C. for at least 30 minutes, wherein the aqueous medium comprises, in step b), ethanol and/or acetate at a total combined concentration is at least 0.1 gL.sup.−1.

There is provided a mixed culture of a first and second microorganism in an aqueous medium, wherein the first microorganism is an acetogenic microorganism capable of converting a carbon source comprising CO and/or CO.sub.2 to acetate and/or ethanol, the second microorganism is a non-acetogenic microorganism capable of metabolising acetate and/or ethanol and the first and second microorganisms are in a homogenous mixture and wherein the aqueous medium comprises oxygen. There is also provided a method of producing substituted and/or unsubstituted organic compounds using the mixed culture.

There is provided a mixed culture of a first and second microorganism in an aqueous medium, wherein the first microorganism is an acetogenic microorganism capable of converting a carbon source comprising CO and/or CO.sub.2 to acetate and/or ethanol, the second microorganism is a non-acetogenic microorganism capable of metabolising acetate and/or ethanol and the first and second microorganisms are in a homogenous mixture and wherein the aqueous medium comprises oxygen. There is also provided a method of producing substituted and/or unsubstituted organic compounds using the mixed culture.

Described is a method for the conversion of 3-methylcrotonyl-CoA into 3-hydroxy-3-methylbutyric acid comprising the steps of:

(a) enzymatically converting 3-methylcrotonyl-CoA into 3-hydroxy-3-methylbutyryl-CoA; and
(b) further enzymatically converting the thus produced 3-hydroxy-3-methylbutyryl-CoA into 3-hydroxy-3-methylbutyric acid
wherein the enzymatic conversion of 3-hydroxy-3-methylbutyryl-CoA into 3-hydroxy-3-methylbutyric acid according to step (b) is achieved by first converting 3-hydroxy-3-methylbutyryl-CoA into 3-hydroxy-3-methylbutyryl phosphate and then subsequently converting the thus produced 3-hydroxy-3-methylbutyryl phosphate into 3-hydroxy-3-methylbutyric acid.

Described is a method for the conversion of 3-methylcrotonyl-CoA into 3-hydroxy-3-methylbutyric acid comprising the steps of:

(a) enzymatically converting 3-methylcrotonyl-CoA into 3-hydroxy-3-methylbutyryl-CoA; and
(b) further enzymatically converting the thus produced 3-hydroxy-3-methylbutyryl-CoA into 3-hydroxy-3-methylbutyric acid
wherein the enzymatic conversion of 3-hydroxy-3-methylbutyryl-CoA into 3-hydroxy-3-methylbutyric acid according to step (b) is achieved by first converting 3-hydroxy-3-methylbutyryl-CoA into 3-hydroxy-3-methylbutyryl phosphate and then subsequently converting the thus produced 3-hydroxy-3-methylbutyryl phosphate into 3-hydroxy-3-methylbutyric acid.

The present invention provides a method of reducing and controlling a hazardous substance in a process of high-value biological conversion of an urban organic waste. The method includes: 1) mixing a sludge, a first urban organic waste and an organic acid with water for acclimation to obtain an acclimatized sludge; 2) stage 1 of biological conversion: mixing the acclimatized sludge with a second urban organic waste to perform anaerobic culture; 3) stage 2 of biological conversion: adding nitrate and bacteria to continue anaerobic culture so as to obtain an organic acid. In the present invention, sludge microbes are acclimatized and then added to high-value chemicals such as acetic acid, propanoic acid and lactic acid prepared in biological conversion of the urban organic waste and then added with bacteria. Thus, by controlling pH value, microbe addition amount and nitrate concentration, the unfavorable effect of the antibiotics and heavy metal ions.

The invention is concerned with a bacterium comprising a inositol to propionic acid pathway gene set that allows said bacterium to convert inositol to propionic acid or a salt or ester thereof. The bacterium can be used as a probiotic or supplement to promote production of propionic acid in the GI tract, thereby preventing and/or treating conditions or diseases that benefit from the production of propionic acid, for example metabolic disease, metabolic syndrome, insulin resistance or insulin resistance-related conditions, particularly dyslipidemia, type 2 diabetes mellitus and insulin-resistance in endocrine diseases.

Yeast cells having a reductive TCA pathway from pyruvate or phosphoenolpyruvate to succinate, and which include at least one exogenous gene overexpressing an enzyme in that pathway, further contain an exogenous transhydrogenase gene.

Yeast cells having a reductive TCA pathway from pyruvate or phosphoenolpyruvate to succinate, and which include at least one exogenous gene overexpressing an enzyme in that pathway, further contain an exogenous transhydrogenase gene.

Provided is a composition comprising a) butyrate and b) a by-product of fermentation of a carbon source-containing feedstock with a Clostridia class bacterium which natively produces butyric acid. Further provided are a feed ingredient, an animal feed and an anti-icing product comprising the composition, methods of manufacturing and uses thereof.