Provided are methods for conferring and/or enhancing herbicide resistance on plants or algae including agricultural crops by introducing prokaryote-derived protoporphynnogen oxidase variants.

The disclosure discloses an Aspergillus niger engineered strain for reducing byproduct succinic acid in a fermentation process of L-malic acid. The Aspergillus niger engineered strain is an Aspergillus niger engineered strain in which fumaric acid reductase frdA and fumaric acid reductase flavoprotein subunit frdB are simultaneously knocked out. The disclosure provides an frdA and frdB gene double-knockout Aspergillus niger strain, and a method for greatly reducing byproduct succinic acid in a fermentation process of L-malic acid. By the disclosure, the byproduct succinic acid accumulated in a production process of malic acid through fermentation of Aspergillus niger is significantly reduced, a cost in a downstream separation and purification process of malic acid is decreased, and good strains are provided for producing malic acid via industrial fermentation.

The disclosure discloses an Aspergillus niger engineered strain for reducing byproduct succinic acid in a fermentation process of L-malic acid. The Aspergillus niger engineered strain is an Aspergillus niger engineered strain in which fumaric acid reductase frdA and fumaric acid reductase flavoprotein subunit frdB are simultaneously knocked out. The disclosure provides an frdA and frdB gene double-knockout Aspergillus niger strain, and a method for greatly reducing byproduct succinic acid in a fermentation process of L-malic acid. By the disclosure, the byproduct succinic acid accumulated in a production process of malic acid through fermentation of Aspergillus niger is significantly reduced, a cost in a downstream separation and purification process of malic acid is decreased, and good strains are provided for producing malic acid via industrial fermentation.

Provided are methods for conferring and/or enhancing herbicide resistance on plants or algae including agricultural crops by introducing prokaryote-derived protoporphyrinogen oxidase variants.

The present invention relates to biocatalysts catalyzing the formation of α-olefins. In particular, the invention provides polypeptides with improved decarboxylase activity on C.sub.10-C.sub.16 free fatty acids, more particularly on C.sub.10 or C.sub.12 free fatty acids, as compared to the P450 fatty acid decarboxylase isolated from the Staphylococcus massiliensis strain S46 (Sm46). The invention further provides recombinant nucleic acids and vectors comprising the coding sequences encoding these polypeptides, genetically engineered host cells expressing said polypeptides and methods for the production of C.sub.9-C.sub.15 α-olefins, more particularly C.sub.9 or C.sub.11 α-olefins, using said polypeptides or said host cells.

Provided are methods for conferring and/or enhancing herbicide resistance on plants or algae including agricultural crops by introducing prokaryote-derived protoporphyrinogen oxidase variants.

Provided are methods for conferring and/or enhancing herbicide resistance on plants or algae including agricultural crops by introducing prokaryote-derived protoporphynnogen oxidase variants.

Live attenuated bacteria vaccines against enteric septicemia of fish, especially catfish, and methods related to the same. Mutant strains of the bacteria Edwardsiella ictaluri (a pathogenic bacterial strain of Enterobacteriaceae) are provided. The mutant Edwardsiella ictaluri bacteria (or other pathogenic bacterial strain of Enterobacteriaceae) contain one or more gene deletions or disruptions that result in less virulent bacterial strains as live attenuated vaccine compositions against virulent wild-type Edwardsiella ictaluri bacteria (or other pathogenic bacterial strain of Enterobacteriaceae). The mutant strains showing the best immunological protection and safety as a vaccine are the triple mutants ESC-NDKL1 (gcvPsdhCfrdA) strain and ESC-NDKL2 (gcvPsdhCmdh) strain, with the ESC-NDKL1 strain providing the greatest safety and efficacy of these two triple mutants.

Disclosed herein are methods of forming chiral 1,2-aminoalcohols and -aminoacids from alkene starting materials by way of an enzymatic cascade reaction sequence that may be accomplished in a single reaction vessel without the need to isolate any intermediates. Also disclosed herein are recombinant nucleic acids, vectors and host cells for use in the methods of the invention.