A method of producing chemicals includes providing fermentative cells; co-feeding any of galacturonate and galacturonate polymers with carbohydrates to the fermentative cells; and producing a chemical from the fermentative cells. The fermentative cells may include any of Clostridium acetobutylicum and Clostridium saccharoperbutylacetonicum. The carbohydrates may include any of glucose, mannose, galactose, fructose, arabinose, xylose, sucrose, lactose, maltose, cellobiose, and starch. The method may include providing a substantially equal proportion of the any of galacturonate and galacturonate polymers and the carbohydrates for co-feeding to the fermentative cells. The method may include altering a proportion of the any of galacturonate and galacturonate polymers to the carbohydrates. The method may include modulating a production of the chemical by altering the proportion of the any of galacturonate and galacturonate polymers to the carbohydrates. The chemical may include any of acetate and butyrate.

A method of producing chemicals includes providing fermentative cells; co-feeding any of galacturonate and galacturonate polymers with carbohydrates to the fermentative cells; and producing a chemical from the fermentative cells. The fermentative cells may include any of Clostridium acetobutylicum and Clostridium saccharoperbutylacetonicum. The carbohydrates may include any of glucose, mannose, galactose, fructose, arabinose, xylose, sucrose, lactose, maltose, cellobiose, and starch. The method may include providing a substantially equal proportion of the any of galacturonate and galacturonate polymers and the carbohydrates for co-feeding to the fermentative cells. The method may include altering a proportion of the any of galacturonate and galacturonate polymers to the carbohydrates. The method may include modulating a production of the chemical by altering the proportion of the any of galacturonate and galacturonate polymers to the carbohydrates. The chemical may include any of acetate and butyrate.

A process includes providing a gaseous substrate comprising CO.sub.2 to a bioreactor; providing acetogenic bacteria and medium to the bioreactor to provide a fermentation broth; providing sodium ions to the bioreactor through one or more sodium ion sources; fermenting the gaseous substrate with the acetogenic bacteria in the fermentation broth to produce one or more organic acids; and controlling a butyric acid to an acetic acid ratio by controlling the pH of the fermentation broth. In one aspect, butyric acid to acetic acid ratio increases when the pH of the fermentation broth decreases, and the ratio of butyric acid to acetic acid concentration decreases when the pH of the fermentation broth increases. The acetogenic bacteria includes a sodium translocating ATPase that is active during fermentation in the bioreactor. The sodium ions are provided so that Na.sup.+ is maintained between 1000 to 11000 ppm (g/g) in culture broth.

A process includes providing a gaseous substrate comprising CO.sub.2 to a bioreactor; providing acetogenic bacteria and medium to the bioreactor to provide a fermentation broth; providing sodium ions to the bioreactor through one or more sodium ion sources; fermenting the gaseous substrate with the acetogenic bacteria in the fermentation broth to produce one or more organic acids; and controlling a butyric acid to an acetic acid ratio by controlling the pH of the fermentation broth. In one aspect, butyric acid to acetic acid ratio increases when the pH of the fermentation broth decreases, and the ratio of butyric acid to acetic acid concentration decreases when the pH of the fermentation broth increases. The acetogenic bacteria includes a sodium translocating ATPase that is active during fermentation in the bioreactor. The sodium ions are provided so that Na.sup.+ is maintained between 1000 to 11000 ppm (g/g) in culture broth.

Provided herein are methods of producing carbon-based compounds from the fermentation of cellulosic feedstocks. In certain embodiments, the cellulosic feedstock and/or source of the cellulosic feedstock is grass, guar gum, leaves, cattails, and/or phragmites.

Described herein are biofilm bioreactors for synthesis at the interface between two liquids, and methods of using such bioreactors for the biotransformation of feedstocks into chemical products. Also contemplated is the extraction of such products.

The present invention relates to glucoamylase variants having improved thermostability. The present invention also relates to polynucleotides encoding the variants; nucleic acid constructs, vectors, and host cells comprising the polynucleotides; and methods of using the variants.

The present invention relates to glucoamylase variants having improved thermostability. The present invention also relates to polynucleotides encoding the variants; nucleic acid constructs, vectors, and host cells comprising the polynucleotides; and methods of using the variants.

The invention provides for the optimal utilization of gas by a fermentation process, whereby the various components within the gas stream are separated to increase the efficiency of the microorganisms. The invention is capable of tailoring the composition of the gas being used by the fermentation process so as to enhance the production of various products. The invention is capable of applying such controlled separation and utilization of gas to produce different products in two fermentation processes in series. The invention is also capable of applying such controlled separation and utilization of gas to produce one product in a first fermentation process, which may be converted to a different product in a second fermentation process. The invention is additionally capable of mitigating culture inhibition.

The invention provides for the optimal utilization of gas by a fermentation process, whereby the various components within the gas stream are separated to increase the efficiency of the microorganisms. The invention is capable of tailoring the composition of the gas being used by the fermentation process so as to enhance the production of various products. The invention is capable of applying such controlled separation and utilization of gas to produce different products in two fermentation processes in series. The invention is also capable of applying such controlled separation and utilization of gas to produce one product in a first fermentation process, which may be converted to a different product in a second fermentation process. The invention is additionally capable of mitigating culture inhibition.