[A strain of Pseudomonas aeruginosa growing on petroleum hydrocarbons]. / Shtamm Pseudomonas aeruginosa, rastushchii na uglevodorodakh nefti.

The strain Pseudomonas aeruginosa BS313 was used to isolate mutants that are capable to utilize octane as the sole carbon source. By means of conjugation plasmids of camphor (CAM) and naphthalene (pBS2) biodegradation were inserted into one of the mutant strains P. aeruginosa BS316. The resultant strain P. aeruginosa BS315 shows the capacity to degrade aliphatic, aromatic and cyclic oil hydrocarbons.

[20alpha- and 20beta-reduction of steroids by immobilized enzyme preparations and Bacillus megaterium cells]. / Izuchenie 20alpha- i 20beta-vosstanovleniia steroidov immobolizovannymi fermentnymi preparatami i kletkami Bacillus megaterium?

Cells of Bacillus megaterium immobilized due to incorporation into polyacrylamide gel retained their viability. They differed significantly in their enzymic activity from free cells: 20alpha- and 20beta-hydroxysteroid dehydrogenase activites were substantially decreased and they also showed the capacity to synthesize significant quantities of a new derivative and to destruct steroids. Immobolized protein fractions maintained 20alpha-hydroxysteroid dehydrogenase and 20beta-hydroxysteroid dehydrogenase activities but their specific activites were lower than those of native protein fractions. It is suggested that the synthesis of new compounds was induced by acrylamide that was bound during polymerization.

[Microbiological transformation of carbohydrates. Glucose isomerization into fructose by washed cells of Streptomyces sp. strain 29]. / Mikrobiologicheskaia transformatsiia uglevodov. Izomerizatsiia gliukozy vo fruktozu otmytymi kletkami Streptomyces sp. shtamm 29.

Glucose-fructose transformation by washed and packed cells of Streptomyces sp. 29 was studied. The cells grown on the nutrient medium containing xylose and Co and Mg salts were capable to perform glucose-fructose isomerization. The cellular activity depended in a great degree on the temperature, pH and initial glucose concentration; to a lesser extent on Co and Mg ions present in the incubation mixture, and did not depend on the age of the culture (within 8-69 hours). The activity reached its maximum at 70-80 degrees C, pH 7.0 and a low concentration of glucose (10(-3) M). Under these conditions the yield of fructose was 50% from the initial glucose concentration (or 100% from the theoretical value). Washed cells of Streptomyces sp. 29 packed into a thermally controlled column continuously transformed glucose to fructose during 24 days with a yield of 30-44%.

[Hydroxylation of indolyl-3-acetic acid by the fungus aspergillus niger IBFM-F-12]. / O gidroksilirovanii indolil-3-uksusnoi kisloty gribom Aspergillus niger IBFM-F-12

Physiological and biochemical properties of the culture of Aspergillus niger IBPM F 12 carrying out hydroxylation IAA in the 4-, 5-, 6-positions of the indole nucleus were studied. The optimal composition of the medium for the cultivation was established. The transformation was performed by the washed fungal mycelium taken in the middle of the growth log-phase at a substrate concentration of I g/l. The correlation between the hydroxylase activity and pH, temperaure and biomass quantity was shown. The method of isolating 4-, 5- and 6-hydroxyindolyl-3-acetic acids in preparative amounts was developed.

[Purification and properties of two enzymes of meta-cleaving the aromatic ring controlled by the biphenyl biodegradation plasmid pBS 241 from Pseudomonas putida]. / Ochistka i svoistva dvukh fermentov meta-rasshchepleniia aromaticheskogo kol'tsa, kontroliruemykh plazmidoi biodegradatsii bifenila pBS 241, iz bakterii Pseudomonas putida]

It was shown that two metapyrocatechases (EC 1.13.11.2) function in Pseudomonas putida BS893. Biphenyl degradative plasmid pBS241 carries the genes of these enzymes. The basic properties of the both enzymes, i. e., MPC1 and MPC2, were investigated. It was found that MPC1 is an enzyme with a molecular mass of 135 kD and has a heterotetrameric subunit structure (alpha 2 beta 2), being made up of two non-identical polypeptides with Mr of 34 and 22.5 kD; pI is 5.15, the pH optimum is at 8.0, a temperature optimum is at 54 degrees C. MPC2 has a molecular mass of 154 kD and possesses a homotetrameric subunit structure (alpha 4); it consists of identical polypeptides with Mr of 41 kD and has a pI of 4.95, a pH optimum at 7.5 and a temperature optimum at 60 degrees C. The substrate specificity of the enzymes was studied, and the Km and Vmax values for substituted catechols were determined. MPC1 shows a high affinity for 2.3-dihydroxybiphenyl and hydrolyzes 3-methylcatechol and catechol (but not 4-methylcatechol) at a low rate. MPC2 has a moderate affinity for catechol, 3- and 4-methylcatechols, but is incapable of cleaving 2.3-dihydroxybiphenyl. Both enzymes share in common some typical properties of metapyrocatechases. The different role of MPC1 and MPC2 in biphenyl catabolism is discussed.

[Study of the initial reaction of enzymatic oxidation of 1,8-dimethylnaphthalene]. / Izuchenie nachal'noi reaktsii fermentativnogo okisleniia 1,8-dimetilnaftalina

Crude enzymatic preparation has been obtained from Pseudomonas bacteria which oxidises 1,8-DMN during 10-hour incubation with the following formation of the same products which are formed when this compound is oxidized by the intact cells. The first product of the oxidation is 1-methyl-8-oxymethylnaphtalene (compound I), obtained as a result of hydroxylation of one methyl group. Probably hydroxylase of 1,8-DMN may be referred to the class of oxigenases of the basis of the absence of 18O incorporation from H218O to compound I, and also resulting from the data on absorption of molecular oxygen during the reaction. The enzyme is completely inhibited by chelating agents of Fe2+ NAD(P)H and Fe2+ stimulates the reaction of 1.8 DMN oxidation.

[Role of cosubstrates in the microbiologic oxidation of xylene isomers by a culture of Pseudomonas aeruginosa]. / Rol' kosubstratov pri mikrobiologicheskom okislenii izomernykh ksilolov kul'turoi Pseudomonas aeruginosa

Cosubstrates (additional substrates) produced different effect on transformation of isomeric xylenes of Pseudomonas aeruginosa 7. The cosubstrates manifested the highest stimulating effect on transformation of o-xylene, on which the culture did not grow, and p-xylene, in the presence of which only a weak growth was detected. The most effective cosubstrates were xylose and maltose which were actively oxidized by the culture but could not serve as carbon sources. One of mechanisms of the cosubstrate action is inhibition (or repression of synthesis) of the enzymes responsible for oxidation of toluic acids by the cosubstrates or their metabolites, which results in their accumulation in the medium. Addition of cosubstrates can regulate transformation stimulating accumulation of different products.

[Degradation of herbicide Alvison-8 by microorganisms]. / Degradatsiia gerbitsida alvison-8 mikroorganizmami

Microbial degradation of a new herbicide, Alvison-8, was studied. No strains capable of growth at the account of this compound as a source of carbon have been found among microorganisms isolated from soil treated with the herbicide and among collection cultures. Some strains can degrade Alvison-8 at a concentration of 100-300 mg/litre in cooxidative conditions. Effective cosubstrates are such compounds which are actively metabolized by microorganisms but cannot maintain intensive growth. In some cases, the cultures grew at the account of cosubstrates and the process consisted of two stages, i. e. degradation occured at the beginning prior to the phase of active growth.

[Naphthalene oxidation by a Pseudomonas putida strain carrying a mutant plasmid]. / Okislenie naftalina shtammom Pseduomonas putida, nesushchim mutantnuiu plazmidu.

Naphthalene oxidation by a parent and a mutant strain of Pseudomonas putida was studied. The parent strain contained a plasmid NPL-1 which controlled oxidation of naphthalene to salicylic acid and was capable of oxidizing salicylate. The mutant strain did not oxidize salicylate because of a mutation in salicylate hydroxylase; it contained also a mutant plasmid NPL-41 which determined constitutive synthesis of naphthalene oxygenase. Salicylic acid which accumulated as a product of naphthalene catabolism in the cultural broth of the wild strain was found to undergo further oxidation by the population of growing cells. The content of salicylic acid in the cultural broth of the mutant strain reached maximum and then remained constant. An anion-exchange resin was tested in order to prevent the inhibition of naphthalene oxygenase by salicylate and to increase the yield of salicylic acid. The transmissible character of the mutant plasmid NPL-41 makes it possible, with the aid of conjugation, to construct Pseudomonas strains which would oxidize naphthalene to salicylic acid without further degradation of this compound.

[Plasmid participation in the degradation of alpha-methylstyrene]. / Uchastie plazmid v degradatsii al'fa-metilstirola.

Pseudomonas acidovorans 9 transforming alpha-methylstyrene into acetophenone contains four types of plasmid DNA with molecular masses of 130, 110, 36 and 54 MD. The loss of the "growth on alpha-methylstyrene" property by this strain correlates with the absence of plasmids with the molecular masses of 130 and 110 MD from the cells. All the types of plasmid DNA are found in transconjugants growing on alpha-methylstyrene and produced by crossing the parent P. acidovorans strain with the plasmidless variant of this strain incapable of alpha-methylstyrene transformation. Apparently, plasmids with the molecular masses of 130 and 110 MD participate in the genetic control of alpha-methylstyrene transformation into acetophenone by P. acidovorans 9.

[Peripheral metabolism of isomeric xylenes by Pseudomonas aeruginosa]. / Periferiinyimetabolizm izomernykh ksilolov kul'turoi Pseudomonas aeruginosa

Microbiological oxidation of xylenes was studied with Pseudomonas aeruginosa, strain 7. The culture grows on m-xylene and, at a lower rate, on p-xylene, but does not grow on o-xylene though partly oxidizes it. Pathways of primary enzymatic oxidation of xylenes by the culture were established. Oxidation of m-xylene follows the pathway described earlier but methylsalicylic acid formed is not accumulated in the medium and is transformed into 3-methylcatechol. The aromatic ring is splitted according to the meta pathway. It has been demonstrated for the first time that o-xylene is oxidized to o-hydroxymethylbenzoic acid.