[Show abstract][Hide abstract] ABSTRACT: Major metabolites formed by Pseudomonas bacteria bearing various naphthalene degradation plasmids were identified using high performance liquid chromatography and mass spectrometry in combination with electrospray ionization. During the growth of P. aureofaciens BS1393(NPL-41) bacteria bearing the plasmid NPL-41, partial oxidation of naphthalene was shown to occur to form the major exometabolite (salicylate) and minor exometabolite (phenol). The growth of P. aureofaciens BS1393(pOV17) bacteria bearing the plasmid pOV17 was accompanied by complete oxidation of naphthalene and formation of trace amounts of salicylate and epoxybenzene. Based on the data of molecular mass spectrometry, we determined the dynamics of CO2 production and oxygen uptake in the process of bacterial growth. The specific quantity of CO2 per unit of cell amount for P. aureofaciens BS1393(NPL-41) bacteria was shown to exceed fivefold that for P. aureofaciens BS1393(pOV17). The respiratory quotient (RQ) representing the ratio of the molar concentrations of metabolic CO2 to consumed oxygen depends on the type of plasmids that determine naphthalene degradation. The value of RQ during the growth of P. aureofaciens BS1393(pOV17) bacteria was almost 1.5 times greater than in the case of P. aureofaciens BS1393(NPL-41). The ratio of O-2 uptake to CO2 formed by the first culture was 4.5 mol O-2/mol CO2; by the second culture, 6.5 mol O-2/mol CO2.
No preview · Article · Dec 2015 · Journal of Analytical Chemistry
[Show abstract][Hide abstract] ABSTRACT: The growth parameters of Achromobacter sp. Kg 16 (VKM B-2534 D), such as biomass and maximum specific growth rate, depended only on the source of phosphorus in the medium, but not on the carbon source or the presence of growth factors. With glyphosate as a sole phosphorus source, they were still 40-50 % lower than in media supplemented with orthophosphate or other organophosphonate-methylphosphonic acid. At the first time process of glyphosate acetylation and accumulation of acetylglyphosate in culture medium were revealed in this strain. Acetylglyphosate isolated from cultural liquid was identified by mass spectroscopy; its mass spectrum fully corresponded with that of chemically synthesized acetylglyphosate. Even poorer growth was observed in media with acetylglyphosate: although the strain was able to utilize this compound as a sole source of phosphorus, the maximum biomass was still 58-70 % lower than with glyphosate. The presence of acetylglyphosate in culture medium could also hinder the utilization of glyphosate as a phosphorus source. Therefore, the acetylation of glyphosate may be a specific feature of Achromobacter sp. Kg 16 responsible for its poor growth on this compound.
Full-text · Article · Nov 2015 · Applied Microbiology and Biotechnology
[Show abstract][Hide abstract] ABSTRACT: We compared data on the extent of bioremediation in soils polluted with oil. The data were obtained using conventional methods of hydrocarbon determination: extraction gas chromatography-mass spectrometry, extraction IR spectroscopy, and extraction gravimetry. Due to differences in the relative abundances of the stable carbon isotopes (C-13/C-12) in oil and in soil organic matter, these ratios could be used as natural isotopic labels of either substance. Extraction gravimetry in combination with characteristics of the carbon isotope composition of organic products in the soil before and after bioremediation was shown to be the most informative approach to an evaluation of soil bioremediation. At present, it is the only method enabling quantification of the total petroleum hydrocarbons in oil-polluted soil, as well as of the amounts of hydrocarbons remaining after bioremediation and those microbially transformed into organic products and biomass.
[Show abstract][Hide abstract] ABSTRACT: The biodegradation of the polycyclic aromatic hydrocarbon phenantherene by the rhizobacterial strain Ensifer meliloti P221, isolated from the root zone of plant grown in PAH-contaminated soil was studied. Bacterial growth and phenanthrene degradation under the influence of root-exuded organic acids were also investigated. Analysis of the metabolites produced by the strain by using thin-layer chromatography, gas chromatography, high-pressure liquid chromatography, and mass-spectrometry revealed that phenanthrene is bioconverted via two parallel pathways. The first, major pathway is through terminal aromatic ring cleavage (presumably at the C3-C4 bond) producing benzocoumarin and 1-hydroxy-2-naphthoic acid, whose further degradation with the formation of salicylic acid is difficult or is very slow. The second pathway is through the oxidation of the central aromatic ring at the C9-C10 bond, producing 9,10-dihydro-9,10-dihydroxyphenanthrene, 9,10-phenanthrenequinone, and 2,2'-diphenic acid. This is the first time that the dioxygenation of phenanthrene at the C9 and C10 atoms, proven by identification of characteristic metabolites, has been reported for a bacterium of the Ensifer genus.
[Show abstract][Hide abstract] ABSTRACT: Antibiotic activity was compared for Cryptococcus humicola cellobiose lipids, the mixture of 2,3,4-О-triacetyl-β-D-glucopyranosyl-(1→4)-(6-О-acetyl-β-D-glucopyranosyl-(1→16)-2,16-dihydroxyhexodecanoic acid and 2,3,4-О-triacetyl-β-D-glucopyranosyl-(1→4)-(6-О-acetyl-β-D-glucopyranosyl-(1→16)-2,17,18-trihydroxyoctotodecanoic acid, and the commercial sophorose lipid mixture of a mono-acetylated acidic sophorose lipid and a di-acetylated acidic sophorose lipid, both containing the C18:1 fatty acid residue. The MIC values of cellobiose lipids were 0.005 and 0.04 mg/mL for Filobasidiella neoformans and Candida tropicalis, respectively. The MIC values of sophorose lipids were 1 and 15 mg/mL for F. neoformans and C. tropicalis, respectively. MIC values for some bacteria were in the range of 10-30 mg/mL for both glycolipid preparations. Both sophorose lipids and cellobiose lipids displayed a membranedamaging activity against F. neoformans. The treatment with these glycolipids reduces the content of ATP in the cells of test cultures and results in their staining with ethidium bromide.
No preview · Article · Jul 2014 · Journal of oleo science
[Show abstract][Hide abstract] ABSTRACT: Distribution of 13C/12C isotopes in vegetative (roots, grapevine, leaves) and generative (berries) parts of vine plants of the West European genetically different varieties Cabernet Sauvignon and Aligoté growing on soils of Krasnodar krai and Rostov oblast, as well as autochthonous varieties Sibirkovy and Krasnostop Zolotovsky growing in Rostov oblast, has been studied using isotopic mass spectrometry methods. It has been shown that the variations of δ13C values in plant tissues and berries are related to the climatic conditions of plant growth: moisture (a sum of annual precipitation) and temperature (a sum of annual effective temperatures). The carbon isotope ratios of vegetative and generative parts of vine plants have been found to be noticeably affected by vine varieties. The different 13C contents in ethanol produced from wine of the Aligoté and Cabernet Sauvignon varieties grown in two Russian vineyard regions are due to vine growth conditions, variety attribution and wine production techniques. An analytically significant parameter determined as exemplified by the Aligoté and Cabernet Sauvignon varieties in fermentation of vine harvested in different seasons and in both vineyard regions was an increased 13C content in ethanol with respect to dry (non-volatile) residue in wine after distillation of ethanol. This characteristic has been determined by a systematic difference of about 1–2‰ between the δ13C value of ethanol and the dry residue. A relative constancy in the carbon isotope composition of ethanol and of the dry residue in the final product is the basis for determining the authenticity of grape wines by means of isotopic mass spectrometry irrespective of natural factors.
Full-text · Article · Dec 2013 · Journal of Analytical Chemistry
[Show abstract][Hide abstract] ABSTRACT: Using molecular and isotopic mass spectrometry, we investigated the toxic effect of naphthalene as a representative of polycyclic aromatic hydrocarbons (PAHs) on plants growing under sterile conditions and plants inoculated with microorganisms capable and incapable of naphthalene degradation. Tobacco plants of the Samsun variety were grown in a closed gas-nutrient system on a mineral medium with sucrose as a carbon source. Naphthalene used as a toxicant at a concentration of 5.2 × 10−4% contained 13C isotope whose amount was characterized by the value δ13C = +281.4 ± 0.6‰ relative to the PDB standard and differed from that of sucrose, the main source of carbon (δ13C = −12.0 ± 0.1‰). Degradation of naphthalene was determined by the inclusion of its carbon in metabolic CO2 and plant tissues (the root, stem, leaves). The effect of naphthalene on plants was indicated by the rates of O2 production and CO2 uptake during the light period as compared with the dark period of exposure. A decrease of the toxic effect of naphthalene on plants was observed only at the inoculation of plants with Pseudomonas aureofaciens BS1393 rhizosphere bacteria bearing plasmid pBS216, which controls the naphthalene biodegradation ability. The occurrence of other heterotrophic microorganisms incapable of naphthalene degradation had no similar protective effect.
Full-text · Article · Dec 2013 · Journal of Analytical Chemistry
[Show abstract][Hide abstract] ABSTRACT: We obtained data on the species composition of mycelial fungi isolated from the air of workrooms and production premises in cheese-making and meat-processing plants. The strains studied were shown to be capable of producing various low-molecular compounds. Many of them are mycotoxins such as α-cyclopiazonic acid (CPA), mycophenolic acid (MPA), citrinin, cladosporin, roquefortine and ergot alkaloids. The profiles of the secondary metabolites were used to elucidate the species names of the isolated strains.
Full-text · Article · Nov 2013 · Food Additives and Contaminants - Part A Chemistry, Analysis, Control, Exposure and Risk Assessment
[Show abstract][Hide abstract] ABSTRACT: By the example of glucose uptake by the soil bacteria Pseudomonas aureofaciens BS1393(pBS216) and Rhodococcus sp. 3–30 immobilized on a solid-phase surface (quartz sand), their growth parameters were determined: growth rate (doubling time), total CO2 production, CO2 production per cell, lag period with respect to substrate uptake, respiratory quotient. The growth of P. aureofaciens and Rhodococcus sp. on glucose revealed (1) differences of the lag period with respect to substrate (lag time of ∼4 h for P. aureofaciens and ∼26 h for Rhodococcus sp.); (2) differences between the maximal rates of CO2 production (∼50 μg C-CO2 g−1 sand h−1 for P. aureofaciens and ∼8.5 μg C-CO2 g−1 sand h−1 for Rhodococcus sp.); (3) differences in CO2 production per cell (∼1.94 × 10−9 μM CO2/CFU for P. aureofaciens and more than ∼3.4 × 10−9 μM CO2/CFU for Rhodococcus sp.). The kinetics of the metabolic CO2 isotopic composition was shown to be determined by the difference in the carbon isotopic characteristics of products in the cell. Upon introduction of glucose into the medium (the preparatory stage of the metabolism), the uptake of intracellular 13C-depleted products (lipids) is noted; at the stage of the maximal cell growth rate, introduced glucose is mainly metabolized; and at the final stage, upon exhaustion of substrate, the “stored” products—the lipid fraction—get involved in the metabolism. At the maximal rate of glucose uptake, the CO2 carbon isotopic fractionation coefficient relative to organic products of microbial biosynthesis was determined to be α = 1.009 ± 0.002.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Wastes generated in production of caprolactam (2-oxohexamethylenimine, ε-caprolactam) and caprolactam-based polymers contain the unreacted monomer and its low-molecular linear and cyclic oligomers. Application of microorganisms for biological treatment of caprolactam- and oligomer-containing wastes can become an alternative to existing waste utilization methods. This work investigated the transformation of caprolactam low-molecular linear oligomers by caprolactam-degrading bacteria bearing degradative plasmids (CAP plasmids).
RESULTS Based on mass spectrometry data, a scheme for the biotransformation of caprolactam linear oligomers is proposed. Oxidative transamination to corresponding dicarboxylic acids can be one of the transformation mechanisms. Oxidative transamination occurs due to a broad substrate specificity of the caprolactam catabolism key enzymes 2-oxoglutarate-6-aminohexanoate transaminase (EC.2.6.1-) and 6-oxohexanoate dehydrogenase (EC.184.108.40.206) whose synthesis is determined by CAP plasmids. Incubation of cells 2.0–3.0 × 109 CFU mL−1 of strains with various plasmid-bacterial host combinations in 2 mmol L−1 solution of a dimer for 96 h leads to its almost complete transformation to a corresponding dicarboxylic acid. The dynamics of the process largely depends on the host strain.
CONCLUSION: Deamination of oligomers in their transformation by the enzyme systems of caprolactam-degrading bacteria can substitute the chemical methods of pretreating caprolactam- and oligomer-containing wastes for their subsequent biological purification.
Full-text · Article · Sep 2012 · Journal of Chemical Technology & Biotechnology
[Show abstract][Hide abstract] ABSTRACT: The secondary metabolite profiles of the fungi of the subgenus Penicillium of the genus Penicillium isolated from permafrost were studied. Most of the tested strains synthesized biologically active alkaloids and polyketides. A novel producer of fumiquinazolines F and G was found. Species names of the strains were defined more exactly on the basis of their secondary metabolite profiles and micro- and macromorphological characteristics.
[Show abstract][Hide abstract] ABSTRACT: The hydrocarbon-oxidizing potential of soil microbiota and hydrocarbon-oxidizing microorganisms introduced into soil was studied based on the quantitative and isotopic characteristics of carbon in products formed in microbial degradation of oil hydrocarbons. Comparison of CO2 production rates in native soil and that polluted with crude oil showed the intensity of microbial mineralization of soil organic matter (SOM) in the presence of oil hydrocarbons to be higher as compared with non-polluted soil, that is, revealed a priming effect ofoil. The amount of carbon of newly synthesized organic products (cell biomass and exometabolites) due to consumed petroleum was shown to significantly exceed that of SOM consumed for production of CO2. The result of microbial processes in oil-polluted soil was found to be a potent release of carbon dioxide to the atmosphere.
No preview · Article · Mar 2012 · Prikladnaia biokhimiia i mikrobiologiia
[Show abstract][Hide abstract] ABSTRACT: 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.
No preview · Article · Jan 2012 · Prikladnaia biokhimiia i mikrobiologiia