Abstract: A method for preparing a feedstuff comprising butyric acid and/or butyrate, comprising: adding a microorganism into a light corn steepwater to provide a mixture, wherein the microorganism comprises a first strain and the first strain is able to metabolize saccharides and/or organic compounds in a fermentation to produce butyric acid; keeping the mixture under an anaerobic atmosphere to conduct the fermentation to provide a fermentation broth; and optionally condensing the fermentation broth. Optionally, the microorganism further comprises a second strain, wherein the second strain is able to fix a carbon oxide.

Abstract: A method of producing butyric acid, comprising: (a) providing a microorganism co-culture system comprising an air-tight container and the following (1) to (3) contained in the air-tight container: (1) a substrate, comprising a saccharide; (2) at least one of a first strain and a second strain, wherein the first strain is able to fix a carbon oxide and the second strain is able to fermentatively metabolize an amino acid, and wherein the first strain produces a first metabolite in the fermentation, the second strain produces a second metabolite in the fermentation, and each of the first metabolite and the second metabolite comprises acetic acid; and (3) a third strain, being able to metabolize the saccharide, the first metabolite and the second metabolite in the fermentation to produce butyric acid and a metabolic byproduct in fermentation, wherein the metabolic byproduct comprises carbon oxide and hydrogen, wherein, when the second strain is present in the co-culture system, the substrate further comprises

Abstract: A microorganism co-culture system, comprising: (1) a substrate, comprising a saccharide (2) at least one of a first strain and a second strain, wherein the first strain is able to fix a carbon oxide the second strain is able to fermentatively metabolize an amino acid, and wherein the first strain produces a first metabolite in the fermentation, and the second strain produces a second metabolite in the fermentation; and (3) a third strain, being able to metabolize the saccharide, the first metabolite and the second metabolite in the fermentation to produce butyric acid and/or butanol, wherein, when the second strain is present in the co-culture system, the substrate further comprises an amino acid.