The present disclosure provides methods for preparing β-substituted tryptophan compounds. The methods include: combining i) an unsubstituted indole or a substituted indole, ii) a β-substituted serine, and iii) a tryptophan synthase β-subunit (i.e., a TrpB); and maintaining the resulting mixture under conditions sufficient to form the β-substituted tryptophan. The TrpB contains at least one amino acid mutation which promotes formation of an amino-acrylate intermediate. New TrpB variants and new β-substituted tryptophan analogs are also described.

The present disclosure relates to an L-amino acid-producing E. coli mutant strain or Corynebacterium glutamicum mutant strain having enhanced L-amino acid productivity, and a method of producing L-amino acid using the same. The L-amino acid-producing E. coli mutant strain and Corynebacterium glutamicum mutant strain according to the present disclosure exhibit an enhanced ability to produce L-amino acid, such as L-tryptophan, L-phenylalanine, L-tyrosine, L-glutamine, L-lysine, L-arginine, L-valine, L-leucine, L-isoleucine, L-threonine, L-histidine, L-serine, or L-citrulline, compared to parent strains thereof, and are capable of producing a high concentration of L-amino acid in high yield.

Provided are a cAMP receptor protein variant, a microorganism including the same, and a method of producing an L-amino acid using the same.

This invention involves to Bacillus licheniformis JSC-69 for producing the 5-HTP, deposited as CGMCC NO: 13533; and a method for the producing 5-HTP using Bacillus licheniformis. Bacillus licheniformis JSC-69 said in this invention produces 5-HTP using tryptophan as the substrate, and the transformation efficiency is 95%˜100%.

Provided herein are biocatalysts and systems thereof for pterin-dependent enzymes and pathways and methods of making and using the same. Provided herein in some embodiments are biocatalysts having a pterin source and a pterin-dependent enzymatic pathway biologically coupled to the pterin source. Tetrahydrobiopterin (referred to herein as BH4 or BH 4) can be the pterin source. The BH4 can be synthesized by a tetrahydrobiopterin synthesis pathway. The tetrahydrobiopterin synthesis pathway can include a GTP cyclohydrase; a pyruvoyl tetrahydropterin synthase; a sepiapterin reductase, and/or any combination thereof. The biocatalyst can further contain a pterin-dependent enzymatic pathway. The pterin-dependent enzymatic pathway can be amino acid mono-oxygenase, phenylalanine hydroxylase, tryptophan hydroxylase, tyrosine hydroxylase, nitric oxide synthase, alkylglycerol monooxygenase, and/or any combination thereof.

The disclosure relates, in some aspects, to compositions and methods useful for production of nitrated aromatic molecules. The disclosure is based, in part, on whole cell systems expressing artificial fusion proteins comprising cytochrome P450 enzymes linked to reductase enzymes. In some aspects, the disclosure relates to methods of producing nitrated aromatic molecules in whole cell systems having artificial fusion proteins comprising cytochrome P450 enzymes linked to reductase enzymes.

The present disclosure relates to a microorganism producing L-tryptophan in which the microorganism is modified such that a protein having an L-tryptophan-exporting activity comprising the amino acid sequence of SEQ ID NO: 1 is expressed, and a method for producing L-tryptophan using the microorganism.

Described herein are recombinant microbial host cells comprising biosynthetic pathways and their use in producing oxidation products and downstream products, e.g., melatonin and related compounds, as well as enzyme variants, nucleic acids, vectors and methods useful for preparing and using such cells. In specific aspects, the present invention relates to monooxygenases, e.g., amino acid hydroxylases, with a modified cofactor-dependency, and to enzyme variants and microbial cells providing for an improved supply of cofactors.

A biotechnological production of tryptophan and derivatives thereof, as well as a method for an enhanced microbial L-tryptophan synthesis. In one aspect the invention provides a bacterial cell being genetically modified to express anindole-3-glycerol phosphate synthase, IGPs, the IGPs being less sensitive to inhibition or even being activated by anthranilate compared to the wild type IGPs of the bacterial cell.

The invention relates to a recombinant, L-amino acid-secreting microorganism of the Enterobacteriaceae family, comprising an DNA fragment having promoter activity that is functionally linked to a polynucleotide coding for a membrane protein, characterized in that the DNA fragment having promoter activity comprises the SEQ ID NO: 8.