Directed evolution toward improved production of L-ribose from ribitol.

Improvement of the one-step production of L-ribose from ribitol using a recombinant Escherichia coli is described. The gene encoding the enzyme mannitol-1-dehydrogenase (MDH) from Apium graveolens has previously been codon-optimized, cloned into the constitutive pZuc10 vector, and expressed in E. coli.

Single-step bioconversion for the preparation of L-gulose and L-galactose.

Both carbohydrate monomers L-gulose and L-galactose are rarely found in nature, but are of great importance in pharmacy R&D and manufacturing. A method for the production of L-gulose and L-galactose is described that utilizes recombinant Escherichia coli harboring a unique mannitol dehydrogenase. The recombinant E.

Efficient production of L-ribose with a recombinant Escherichia coli biocatalyst.

A new synthetic platform with potential for the production of several rare sugars, with l-ribose as the model target, is described. The gene encoding the unique NAD-dependent mannitol-1-dehydrogenase (MDH) from Apium graveolens (garden celery) was synthetically constructed for optimal expression in Escherichia coli. This MDH enzyme catalyzes the interconversion of several polyols and their l-sugar counterparts, including the conversion of ribitol to l-ribose.

New insight into the mechanism of methyl transfer during the biosynthesis of fosfomycin.

Hydroxyethylphosphonate is a required intermediate in fosfomycin biosynthesis.

Heterologous production of fosfomycin and identification of the minimal biosynthetic gene cluster.

Fosfomycin is a clinically utilized, highly effective antibiotic, which is active against methicillin- and vancomycin-resistant pathogens. Here we report the cloning and characterization of a complete fosfomycin biosynthetic cluster from Streptomyces fradiae and heterologous production of fosfomycin in S. lividans.

Efficient regeneration of NADPH using an engineered phosphite dehydrogenase.

The in situ regeneration of reduced nicotinamide cofactors (NAD(P)H) is necessary for practical synthesis of many important chemicals. Here, we report the engineering of a highly stable and active mutant phosphite dehydrogenase (12x-A176R PTDH) from Pseudomonas stutzeri and evaluation of its potential as an effective NADPH regeneration system in an enzyme membrane reactor. Two practically important enzymatic reactions including xylose reductase-catalyzed xylitol synthesis and alcohol dehydrogenase-catalyzed (R)-phenylethanol synthesis were used as model systems, and the mutant PTDH was directly compared to the commercially available NADP(+)-specific Pseudomonas sp.

Directed evolution of a thermostable phosphite dehydrogenase for NAD(P)H regeneration.

NAD(P)H-dependent oxidoreductases are valuable tools for synthesis of chiral compounds. The expense of the cofactors, however, requires in situ cofactor regeneration for preparative applications. We have attempted to develop an enzymatic system based on phosphite dehydrogenase (PTDH) from Pseudomonas stutzeri to regenerate the reduced nicotinamide cofactors NADH and NADPH.