[Enzymatic synthesis of L-malic acid from fumaric acid using immobilized Escherichia coli cells]. / Enzimaticheskii sintez L-iablochnoi kisloty iz fumarovoi s pomoshch'iu immobilizovannykh kletok Escherichia coli.

Optimal conditions were chosen for cultivation of Escherichia coli 85 cells with a rather high fumarate-hydratase activity on a cheap medium containing no edible raw material. An active biocatalyst for the synthesis of L-malic acid from fumaric acid was obtained based on E. coli 85 cells immobilized in carrageenan. The enzymatic synthesis of L-malic acid from potassium fumarate was kinetically studied and optimized. Some thermodynamic parameters of fumaric acid hydration into malic acid were determined. A technique for assaying the reaction mixture was developed that involved high performance liquid chromatography.

[Use of enzymatic hydrolysates of microorganism biomass in media for culturing Str. lactis, the producer of nisin]. / Primenenie fermentnykh gidrolizatov biomassy mikroorganizmov v sredakh dlia kul'tivirovaniia Str. lactis, produtsenta nizina.

Fermentative hydrolysates (FH) of the protein-vitamin complex (PVC) were used for the first time in media for cultivation of Str. lactis. It was found that the FH may be used in the media for cultivation of streptococci as a source of nitrogen instead of the yeast autolysate from baker's yeast and the level of nisin biosynthesis did not change. The replacement of the yeast autolysate by the FH is possible in both flasks with low volumes of the medium and 401 fermenters with 25 liters of the medium. The BVC FH is not a food raw material and its cost is low, which makes it advantageous.