Enhancing a Sphaerobacter thermophilus ω-transaminase for kinetic resolution of β- and γ-amino acids.

Sphaerobacter thermophilus synthesizes an ω-transaminase (ω-TA) that allows the production of enantiomerically pure β-amino acids. To obtain ω-TA variants with a higher activity and more favorable properties for industrial use, we modified critical amino acid residues either in the catalytic center or in a previously proposed signature motif critical for aromatic β-amino acid ω-TAs. Seventeen different variants of this enzyme were generated and their activity was examined with four β-amino acids and one γ-amino acid, and compared with the wildtype's activity.

A transaminase with β-activity from for the production of enantiopure β-amino acids.

Enantioselective transamination of amino acids is a great challenge in biotechnology as suitable enzymes with wide substrate spectrum are rare. Here, we present a new transaminase from (VboTA, ω-transaminase) which is specific for β-amino acids. The amino acid sequence of VboTA is similar to an ω-transaminase from , for which a crystal-structure is available.

Characterization of Catechol-1,2-Dioxygenase (Acdo1p) From and Investigation of Its Role in the Catabolism of Aromatic Compounds.

Gallic acid, protocatechuic acid, catechol, and pyrogallol are only a few examples of industrially relevant aromatics. Today much attention is paid to the development of new microbial factories for the environmentally friendly biosynthesis of industrially relevant chemicals with renewable resources or organic pollutants as the starting material. The non-conventional yeast, , possesses attractive properties for industrial bio-production processes such as thermo- and osmotolerance.

Characterization of recombinant laccase from Trametes versicolor synthesized by Arxula adeninivorans and its application in the degradation of pharmaceuticals.

Recent years have seen an increasing interest in laccase enzymes. Due to their ability of oxidizing various substrates, they are nowadays applied in multiple industrial fields including pulp delignification, textile dye bleaching, and bioremediation. In contrast to laccase production from native sources, with its generally low yield and high cost, heterologous laccase expression is far better suited to meet the growing industrial demands.

Selection of the Optimal Yeast Host for the Synthesis of Recombinant Enzymes.

Yeasts, like Arxula adeninivorans, Hansenula polymorpha, Pichia pastoris, Debaryomyces hansenii, Debaryomyces polymorphus, Schwanniomyces occidentalis, Yarrowia lipolytica, and Saccharomyces cerevisiae are frequently used producers of recombinant enzymes, particularly when posttranslational modifications are mandatory to obtain full functionality. The wide-range transformation/expression platform presented in this chapter can be used to select the optimal yeast host for high-level synthesis of the desired enzyme with favorable biochemical properties. This platform is composed of a selection marker and up to four expression modules in a linearized cassette.