Disclosed herein is an endotoxin-free asparaginase enzyme. Also disclosed are methods of using the disclosed enzyme to treat subjects with a disease treatable by depletion of asparagine. For example, the disclosed endotoxin-free asparaginase enzyme is useful in the treatment or the manufacture of a medicament for use in the treatment of acute lymphoblastic leukemia (ALL) in both adults and children, as well as other conditions where asparagine depletion is expected to have a useful effect.

The present disclosure provides compositions and methods for using hydrogenotrophic microorganisms capable of biologically utilizing or converting H.sub.2 and CO and/or CO.sub.2 gas into high-value molecules and biological material, such as essential amino acids (e.g., lysine, threonine, methionine) and animal feed.

The present disclosure provides compositions and methods for using hydrogenotrophic microorganisms capable of biologically utilizing or converting H.sub.2 and CO and/or CO.sub.2 gas into high-value molecules and biological material, such as essential amino acids (e.g., lysine, threonine, methionine) and animal feed.

The present disclosure provides novel bacterial strains with altered expression or start codon modification of one or more RNA degradation/processing genes. The RNA degradation genes of the present disclosure are controlled by heterologous promoters. The present disclosure further describes methods for generating microbial strains comprising heterologous promoter sequences operably linked to RNA degradation/processing genes.

The present disclosure provides novel bacterial strains with altered expression or start codon modification of one or more RNA degradation/processing genes. The RNA degradation genes of the present disclosure are controlled by heterologous promoters. The present disclosure further describes methods for generating microbial strains comprising heterologous promoter sequences operably linked to RNA degradation/processing genes.

The present disclosure discloses a thermophilic L-asparaginase mutant and screening and fermentation methods thereof, and belongs to the field of gene engineering, enzyme engineering and fermentation engineering. In bacillus subtilis 168, a Pyrococcus yayanosii CH1-derived L-asparaginase encoding gene is used as a template, and a mutation library is constructed by an error-prone PCR (epPCR) technology. A mutant strain with improved specific enzyme activity is screened through a high-flux screening method of synchronous cell disruption and enzyme activity measurement. Mutated residues included in a positive mutant are analyzed to construct a composite mutant strain S17G/A90S/R156S/K272A with improved specific enzyme activity and specific enzyme activity of 3108 U/mg. An expression quantity of the composite mutant strain in the bacillus subtilis 168 is increased through measures of a strong promoter P.sub.43 and RBS optimization. Finally, the bacillus subtilis 168 with a gene of the L-asparaginase composite mutant strain is subjected to enzyme production fermentation in a 5 L fermentation tank through culture medium optimization and pH and feeding coupling strategies. The enzyme activity yield of the L-asparaginase is up to 6453+/127 U/mL.

A method for producing an L-amino acid such as L-lysine is provided. An L-amino acid is produced by culturing a bacterium having an L-amino acid-producing ability, which has been modified so that the activity of a carotenoid biosynthesis enzyme is increased, in a medium, and collecting the L-amino acid from the medium.

A method for producing an L-amino acid such as L-lysine is provided. An L-amino acid is produced by culturing a bacterium having an L-amino acid-producing ability, which has been modified so that the activity of a carotenoid biosynthesis enzyme is increased, in a medium, and collecting the L-amino acid from the medium.

The present invention relates to a recombinant nucleic acid molecule, a recombinant micro-organism, to a method for producing alanine and to the use of the recombinant nucleic acid molecule or the recombinant microorganism for the fermentative production of alanine.

The present invention relates to a recombinant nucleic acid molecule, a recombinant micro-organism, to a method for producing alanine and to the use of the recombinant nucleic acid molecule or the recombinant microorganism for the fermentative production of alanine.