An improved racemase/acylase biotransformation for the preparation of enantiomerically pure amino acids.

Using directed evolution, a variant N-acetyl amino acid racemase (NAAAR G291D/F323Y) has been developed with up to 6-fold higher activity than the wild-type on a range of N-acetylated amino acids. The variant has been coupled with an enantiospecific acylase to give a preparative scale dynamic kinetic resolution which allows 98% conversion of N-acetyl-DL-allylglycine into D-allylglycine in 18 h at high substrate concentrations (50 g L(-1)). This is the first example of NAAAR operating under conditions which would allow it to be successfully used on an industrial scale for the production of enantiomerically pure α-amino acids.

Directed evolution of a thermostable l-aminoacylase biocatalyst.

Enzymes from extreme environments possess highly desirable traits of activity and stability for application under process conditions. One such example is l-aminoacylase (E.C.

Managing the risk of glyphosate resistance in Australian glyphosate- resistant cotton production systems.

Background: Glyphosate-resistant cotton varieties are an important tool for weed control in Australian cotton production systems. To increase the sustainability of this technology and to minimise the likelihood of resistance evolving through its use, weed scientists, together with herbicide regulators, industry representatives and the technology owners, have developed a framework that guides the use of the technology. Central to this framework is a crop management plan (CMP) and grower accreditation course.

A thermostable L-aminoacylase from Thermococcus litoralis: cloning, overexpression, characterization, and applications in biotransformations.

A thermostable L-aminoacylase from Thermococcus litoralis was cloned, sequenced, and overexpressed in Escherichia coli. The enzyme is a homotetramer of 43 kDa monomers and has an 82% sequence identity to an aminoacylase from Pyrococcus horikoshii and 45% sequence identity to a carboxypeptidase from Sulfolobus solfataricus. It contains one cysteine residue that is highly conserved among aminoacylases.