Isoformes of Malate Dehydrogenase from <Emphasis Type="Italic">Rhodovulum Steppense</Emphasis> A-20s Grown Chemotrophically under Aerobic Conditions

Three malate dehydrogenase isoforms (65-, 60-, and 71-fold purifications) with specific activities of 4.23, 3.88, and 4.56 U/mg protein were obtained in an electrophoretically homogenous state from Rhodоvulum steppense bacteria strain A-20s chemotrophically grown under aerobic conditions. The physicochemical and kinetic properties of malate dehydrogenase isoforms were determined. The molecular weight and the Michaelis constants were determined; the effect of hydrogen ions on the forward and reverse MDH reaction was studied. The results of the study demonstrated that the enzyme consists of subunits; the molecular weight of subunits was determined by SDS-PAGE.     

Isolation,Purification, and Properties of Peroxisomal Malate Dehydrogenase from Maize Mesophyll

Peroxisomal malate dehydrogenase (EC 1.1.1.37) with a specific activity of 533 U/mg (144-fold purification) and a yield of 5% was obtained in a homogeneous state by a purification scheme including sucrose gradient centrifugation from maize mesophyll. The Michaelis constants for the forward and reverse reactions were determined to be 11.6 mM and 256 μM, and the pH optimum was 9.5 and 9.0, respectively. Analysis of the molecular weight of the native enzyme and its subunits showed that the peroxisomal malate dehydrogenase was a homodimer. It was established that the isolated and purified isoform of the enzyme had a higher affinity for malate and NAD⁺ in comparison with the mitochondrial and cytoplasmic isoforms.     

A New Oil-Oxidizing Micromycete Fusarium sp.

The strain Fusarium sp. no. 56 isolated from natural oil-containing soil samples taken near the city of Oktyabr'skii, Republic of Bashkortostan, displayed a pronounced capability of biotransforming oil and its light and heavy fractions. This micromycete is nonpathogenic and can grow at 5–10°C. The latter property is of practical significance for its uses in soil and water bioremediation under the cold climatic conditions of Bashkortostan and other regions.     

Physicochemical and catalytic properties of NAD<Superscript>+</Superscript>- dependent malate dehydrogenase isoforms from maize mesophyll

Malate dehyrogenase isoforms (46- and 70-fold purifications) with specific activities of the 640 and 990 U/mg protein were obtained in an electrophoretically homogeneous state from maize mesophyll. The physicochemical and catalytic properties of these isoforms were studied. The molecular weight and the Michaelis constants were determined; the effect of hydrogen ions on the forward and reverse MDH reaction was studied. The results of SDS-PAGE demonstrated that malate dehydrogenase isoforms have an oligomeric structure comprised of identical subunits. The first isoform with a molecular weight of 126.58 kDa is tetramer, and the second isoform with a molecular weight of 63.3 is dimer.     

A new oil-oxidizing micromycete Fusarium sp

The strain Fusarium sp. No. 56 isolated from natural oil-containing soil samples taken near the city of Oktyabr'skii, Republic of Bashkortostan, displayed a pronounced capability of biotransforming oil and its light and heavy fractions. This micromycete is nonpathogenic and can grow at 10 degrees C. The latter property is of practical significance for its uses in soil and water bioremediation under cold climatic conditions of Bashkortostan and other regions.