Biocatalytic conversion systems and methods of producing and using same that have improved yields are disclosed. The systems and methods involve co-fermentation of sugars and gaseous substrates for alcohol, ketone, and/or organic acid production. The systems and methods may include biocatalytically converting at least one sugar substrate into at least one of alcohol, at least one ketone, and/or at least one organic acid. The systems and methods may further include biocatalytically converting gases that comprise CO.sub.2 and H.sub.2 to at least one alcohol and/or at least one organic acid, thereby adding extra revenue to biorefineries.

Microbial cell lines suitable for industrial-scale production of organic acids and methods of making and isolating such cell lines, and using the cell lines for production of organic acids.

Microbial cell lines suitable for industrial-scale production of organic acids and methods of making and isolating such cell lines, and using the cell lines for production of organic acids.

A method of producing higher alkanones, preferably 6-undecanone, from ethanol and/or acetate, may include: (a) contacting the ethanol and/or acetate with at least one microorganism capable of carrying out carbon chain elongation to produce hexanoic acid and/or an ester thereof from the ethanol and/or acetate; (b) extracting the hexanoic acid and/or ester thereof from the contacting (a) using at least one extractant in an aqueous medium, the extractant including at least one alkyl-phosphine oxide and at least one C12+ alkane; or at least one trialkylamine and at least one C12+ alkane; and (c) contacting the extracted hexanoic acid and/or ester thereof from (b) with at least one ketonization catalyst and eventually a further C1 to C22 alkanoic acid under suitable reaction conditions for chemical ketonization of hexanoic acid and eventually the further alkanoic acid to a higher alkanone, preferably 6-undecanone.

A method of producing higher alkanones, preferably 6-undecanone, from ethanol and/or acetate, may include: (a) contacting the ethanol and/or acetate with at least one microorganism capable of carrying out carbon chain elongation to produce hexanoic acid and/or an ester thereof from the ethanol and/or acetate; (b) extracting the hexanoic acid and/or ester thereof from the contacting (a) using at least one extractant in an aqueous medium, the extractant including at least one alkyl-phosphine oxide and at least one C12+ alkane; or at least one trialkylamine and at least one C12+ alkane; and (c) contacting the extracted hexanoic acid and/or ester thereof from (b) with at least one ketonization catalyst and eventually a further C1 to C22 alkanoic acid under suitable reaction conditions for chemical ketonization of hexanoic acid and eventually the further alkanoic acid to a higher alkanone, preferably 6-undecanone.

Disclosed in the present invention is a fluoroacetate dehalogenase mutant, a sequence of the fluoroacetate dehalogenase mutant comprising a mutated sequence having an amino acid residue H at position 155 and/or an amino acid residue W at position 156, as shown in SEQ ID NO: 1; the fluoroacetate dehalogenase mutant has activity catalyzing bromination of a substrate, particularly a 2-bromobutyric acid substrate. Also provided in the present invention is an application of said fluoroacetate dehalogenase mutant in the preparation of (R)-2-bromobutyric acid and/or (R)-2-hydroxybutyric acid. When using the fluoroacetate dehalogenase mutant of the present invention to prepare (R)-2-bromobutyric acid, production costs are low and stereoselectivity is high, facilitating industrialized production.

Disclosed in the present invention is a fluoroacetate dehalogenase mutant, a sequence of the fluoroacetate dehalogenase mutant comprising a mutated sequence having an amino acid residue H at position 155 and/or an amino acid residue W at position 156, as shown in SEQ ID NO: 1; the fluoroacetate dehalogenase mutant has activity catalyzing bromination of a substrate, particularly a 2-bromobutyric acid substrate. Also provided in the present invention is an application of said fluoroacetate dehalogenase mutant in the preparation of (R)-2-bromobutyric acid and/or (R)-2-hydroxybutyric acid. When using the fluoroacetate dehalogenase mutant of the present invention to prepare (R)-2-bromobutyric acid, production costs are low and stereoselectivity is high, facilitating industrialized production.

Compositions and methods for the production of L-glufosinate are provided. The method involves converting racemic glufosinate to the L-glufosinate enantiomer or converting PPO to L-glufosinate in an efficient manner. In particular, the method involves the specific amination of PPO to L-glufosinate, using L-glutamate, racemic glutamate, or another amine source as an amine donor. PPO can be obtained by the oxidative deamination of D-glufosinate to PRO (2-oxo-4-(hydroxy (methyl) phosphinoyl) butyric acid) or generated via chemical synthesis. PPO is then converted to L-glufosinate using a transaminase in the presence of an amine donor. When the amine donor donates an amine to PPO. L-glufosinate and a reaction by product are formed. Because the PPO remaining represents a yield loss of L-glufosinate, it is desirable to minimize the amount of PPO remaining in the reaction mixture. Degradation, other chemical modification, extraction, sequestration, binding, or other methods to reduce the effective concentration of the by-product. i.e., the corresponding alpha ketoacid or ketone to the chosen amine donor will shift the reaction equilibrium toward L-glufosinate, thereby reducing the amount of PPO and increasing the yield of L-glufosinate. Therefore, the methods described herein involve the conversion or elimination of the alpha ketoacid or ketone by-product to another product to shift the equilibrium towards L-glufosinate.

Compositions and methods for the production of L-glufosinate are provided. The method involves converting racemic glufosinate to the L-glufosinate enantiomer or converting PPO to L-glufosinate in an efficient manner. In particular, the method involves the specific amination of PPO to L-glufosinate, using L-glutamate, racemic glutamate, or another amine source as an amine donor. PPO can be obtained by the oxidative deamination of D-glufosinate to PRO (2-oxo-4-(hydroxy (methyl) phosphinoyl) butyric acid) or generated via chemical synthesis. PPO is then converted to L-glufosinate using a transaminase in the presence of an amine donor. When the amine donor donates an amine to PPO. L-glufosinate and a reaction by product are formed. Because the PPO remaining represents a yield loss of L-glufosinate, it is desirable to minimize the amount of PPO remaining in the reaction mixture. Degradation, other chemical modification, extraction, sequestration, binding, or other methods to reduce the effective concentration of the by-product. i.e., the corresponding alpha ketoacid or ketone to the chosen amine donor will shift the reaction equilibrium toward L-glufosinate, thereby reducing the amount of PPO and increasing the yield of L-glufosinate. Therefore, the methods described herein involve the conversion or elimination of the alpha ketoacid or ketone by-product to another product to shift the equilibrium towards L-glufosinate.

A biomass processing system is disclosed whereby a counter flow path is provided for recovering yielded product from at least two fermentation stages. In certain configurations, the counter flow path is associated with respective extraction stages that correspond to each respective fermentation stages. To enhance product recovery, certain configurations also disclose mechanical grinding of biomass between fermentation stage to enhance a surface area for further subsequent processing of the biomass. To yet further enhance the system, certain configurations discloses a cell recovery sub-system that agitates processed biomass to separate cells from undigested residues. The recovered cells may be recycled to fermentation stages in the system.