[Transformation of amides by adherent rhodococcus cells possessing amidase activity].

We report the development of a heterogeneous biocatalyst for the hydrolysis of amides that is based on cell adhesion ofamidase-containing Rhodococci on activated birch carbon (ABC) and crude carbon. We investigated the properties of the obtained biocatalyst in the hydrolysis reaction of acrylamide to acrylic acid and nicotinamide to nicotinic acid, as well as in a model reaction of racemic lactamide hydrolysis to a mixture of D- and L-isomers of lactic acid. We show that a six- and threefold increase in the concentrations of adherent and suspended cells, respectively, results in a reduction of amidase activity by 3 and 30 times, respectively.

[Change in the concentration of intracellular ATP during adhesion of Rhodococcus ruber gt1 and pseudomonas fluorescens C2 cells on carbon supports].

The effect of immobilization of nitrile-utilizing bacteria Rhodococcus ruber gt1 and Pseudomonasfluorescens C2 by adhesion on carbon supports on the content of the intracellular ATP immediately after adsorption and after 2 h and 24-48 h after transfer of the adhered cells into a fresh nutrient medium was studied. Adhesion was shown to lead to a decreased concentration ofATP in a cell by one order of magnitude or more in the first hours in a fresh nutrient medium that'can be attributed to energetic consumption upon the initiation of biofilm formation. A gradual rise in the quantity of ATP, which was calculated per 1 mg of adsorbed cells, was reported to take place in daily and two-daily biofilms, which confirms the cells remain viable.

[Transformation of 2- and 4-cyanopyridines by free and immobilized cells of nitrile-hydrolyzing bacteria].

The transformation dynamics of 2- and 4-cyanopyridines by cells suspended and adsorbed on inorganic carriers has been studied in the Rhodococcus ruber gt 1 strain possessing nitrile hydratase activity and the Pseudomonas fluorescens C2 strain containing nitrilase. It was shown that both nitrile hydratase and nitrilase activities of immobilized cells against 2-cyanopyridine were 1.5-4 times lower compared to 4-cyanopyridine and 1.

[Catalytic properties of a nitrile hydratase immobilized on activated chitosan].

The catalytic properties of a nitrile hydratase, isolated from a strain of Rhodococcus ruber gt1 and immobilized by covalent cross-linking with chitosan activated with 0.1% benzoquinone solution, have been investigated. The kinetic parameters ofacrylonitrile hydration catalyzed by immobilized nitrile hydratase and the enzyme in a solution have been determined.

[A study of the catalytic properties of the nitrile hydratase immobilized on aluminum oxides and carbon-containing adsorbents].

The nitrile hydratase isolated from Rhodococcus ruber strain gt1, displaying a high nitrile hydratase activity, was immobilized on unmodified aluminum oxides and carbon-containing adsorbents, including the carbon carrier Sibunit. The activity and operational stability of the immobilized nitrile hydratase were studied in the reaction of acrylonitrile transformation into acrylamide. It was demonstrated that an increase in the carbon content in the carrier led to an increase in the amount of adsorbed enzyme and, concurrently, to a decrease in its activity.

[Immobilization of Rhodococcus ruber strain gt1, possessing nitrile hydratase activity, on carbon sorbents].

Rhodococcus ruber strain gtl, possessing nitrile hydratase activity, was immobilized by adsorption on carbon supports differing in structure and porosity. The adsorption capacity of the supports towards cells, the substrate of the nitrile hydratase reaction (acrylonitrile), and the product (acrylamide) was studied. Also, the effect of immobilization and nitrile hydratase activity of bacteria was investigated, and the operational stability of the immobilized biocatalyst was determined.

[Effects of nitriles and amides on the growth and the nitrile hydratase activity of the Rhodococcus sp. strain gt1].

Effects of some nitriles and amides, as well as glucose and ammonium, on the growth and the nitrile hydratase (EC 4.2.1.