[Detoxification of high concentrations of trinitrotoluene by bacteria].

The ability of the strains-destructors of various aromatic compounds to utilize trinitrotoluene (TNT) up to concentration of 70 mg/1 was shown. An increase in the TNT concentration from 100 to 150 mg/1 did not inhibit its conversion rate by the Kocuria palustris RS32 strain. The Acinetobacter sp. VT 11 strain utilized TNT as a sole substrate for growth; 3,5-dinitro-4-methyl anilide acetate and 2,6-dinitro-4-aminotoluene were identified as intermediates of TNT degradation by active strains of Pseudomonas sp. VT-7W and Kocuria rosea RS51. At the same time, 4-methyl-3,5-dinitroformamide was discovered for the first time upon the TNT destruction by the bacteria strains of Rhodococcus opacus 1G and Rhodococcus sp. VT-7. The active bacterial strains achieved an 82-90% destruction of TNT when they were introduced into the soil.

[The microbial transformation of phenanthrene and anthracene].

The transformation of phenanthrene and anthracene by Rhodococcus rhodnii 135, Pseudomonas fluorescens 26K, and Arthrobacter sp. K3 is studied. Twenty-one intermediates of phenanthrene and anthracene transformation are identified by HPLC, mass spectrometry, and NMR spectroscopy. P. fluorescens 26K and Arthrobacter sp. K3 are found to produce a wide range of intermediates, whereas R. rhodnii 135 oxidizes phenanthrene, resulting in the formation of a sole product, 3-hydroxyphenanthrene. Putative transformation pathways of phenanthrene and anthracene are proposed for the three bacterial strains studied. These strains can be used to obtain valuable compounds (such as hydroxylated polycyclic aromatic hydrocarbons) that are difficult to produce by chemical synthesis.

[Fluorene cometabolism by Rhodococcus rhodochrous and Pseudomonas fluorescens]. / Kometabolizm fluorena kul'turami Rhodococcus rhodochrous i Pseudomonas fluorescens.

The transformation of fluorene by Rhodococcus rhodochrous strain 172 grown on sucrose and Pseudomonas fluorescens strain 26K grown on glycerol was studied as a function of the substrate concentration and the growth phase. Under certain cultivation conditions, fluorene was completely consumed from the medium. The specific transformation rate of fluorene was considerably higher when it was transformed in the presence of the cosubstrates than when it served as the sole carbon source. An approach to the evaluation of the specific transformation rate of fluorene during batch cultivations is proposed.

[Fluorene degradation by bacteria of the genus Rhodococcus]. / Prevrashchenie fluorena bakteriiami roda Rhodococcus.

Of the four investigated Rhodococcus strains (R. rhodochrous 172, R. opacus 4a and 557, and R. rhodnii 135), the first three strains were found to be able to completely transform fluorene when it was present in the medium as the sole source of carbon at a concentration of 12-25 mg/l. At a fluorene concentration of 50-100 mg/l in the medium, the rhodococci transformed 50% of the substrate in 14 days. The addition of casamino acids and sucrose (1-5 g/l) stimulated fluorene transformation, so that R. rhodochrous 172 could completely transform it in 2-5 days. Nine intermediates of fluorene transformation were isolated, purified, and structurally characterized. It was found that R. rhodnii 135 and R. opacus strains 4a and 557 hydroxylated fluorene with the formation of 2-hydroxyfluorene and 2,7-dihydroxyfluorene. R. rhodochrous 172 transformed fluorene via two independent pathways to a greater degree than did the other rhodococci studied.