Forgot your password?
New user?
New Window Opens on the Secret Life of Microbes: Scientists Develop First Microbial Profiles of Ecosystems
CAS announces the release of SciFinder Scholar for Mac OS X
Press Releases
Press Releases
| Check out our New Publishers' Select for Free Articles |
Applied Biochemistry and Microbiology (v.47, #6)
Use of basidiomycetes in industrial waste processing and utilization technologies: Fundamental and applied aspects (review) by N. A. Kulikova; O. I. Klein; E. V. Stepanova; O. V. Koroleva (pp. 565-579).
This review provides an analysis of recent data on the mechanisms of degradation of lignocellulosic materials and xenobiotics by basidiomycetes. Special attention is given to the analysis of the current state of research of ligninolytic enzymes and their involvement in the degradation of xenobiotics. Data on the practical use of basidiomycetes for bioconversion of industrial wastes are systematized. The most promising areas of bioconversion technologies are considered, such as contaminated water purification (including wastewater), cleanup of soils contaminated with heavy metals and xenobiotics, and degradation of difficult-to-degrade substrates (lignin and lignocellulose wastes, low-energy coal, and synthetic polymers).
Histone-like proteins of bacteria (review) by A. M. Anuchin; A. V. Goncharenko; O. I. Demidenok; A. S. Kaprelyants (pp. 580-585).
Four major families of bacterial histone-like proteins (HU, IHF, H-NS, FIS), united on the basis of structural similarity and performing specific structural and regulatory functions in the cell, are discussed. Histone-like proteins perform topological modification of the chromosome (twisting, bending, and folding) and directly regulate the functioning of promoters of individual operons. Histone-like proteins are critical for the regulation of cell metabolism, are involved in the response to environmental changes, and play a key role in the transition to and maintenance of the resting cells of bacteria.
Cloning and sequence analysis of complete gene encoding an alkaline lipase from Penicillium cyclopium by H. M. Zhang; M. C. Wu; J. Guo; J. F. Li (pp. 586-593).
The complete gene (PG37 lip) encoding an alkaline lipase (PG37 LipI) was cloned from the genomic DNA of Penicillium cyclopium PG37. The cloned PG37 lipI is 2.020 bp in length, consisting of 632 bp of the 5′ flanking promoter region and 1.388 bp of the downstream fragment that contains 6 exons and 5 short introns. The promoter region harbors putative TATA box, CAAT box and several transcription factor binding sites. The open reading frame (ORF) encodes a PG37 LipI of 285 amino acid residues, which was predicted to contain a 20-aa signal peptide, a 7-aa propeptide and a 258-aa mature peptide with a conserved motif Gly-X-Ser-X-Gly. However, PG37 Lip shows only 32%, 30%, 28% and 26% identity with lipases of Aspergillus parasiticus, Penicillium camembertii, Thermomyces lanuginosus and Rhizomucor miehei, respectively. It was predicted that the main secondary structures of PG37 Lip are α-helix and random coil. Three amino acid residues, Ser132-Asp188-His241, compose the enzymatic active center in the tertiary structure.
Construction of Streptomyces nogalater Lv65 strains with enhanced nogalamicin biosynthesis using regulatory genes by D. A. Klimishin; M. V. Rabyk; T. P. Gren’; O. Ya. Nimets’; M. A. Gonchar; A. N. Gromyko; V. A. Fedorenko (pp. 594-598).
Influence of cloned regulatory genes on nogalamycin biosynthesis by Streptomyces nogalater LV65 strain has been studied. Gene snorA from the S. nogalater genome was cloned in multicopy replicative plasmid pSOKA and integrative plasmid pR3A. Introduction of these plasmids into S. nogalater wild type cells resulted in enhanced nogalamicin biosynthesis. A similar effect was observed at heterologous expression of gene (p)ppGpp-synthetase gene relA cloned from Streptomyces coelicolor A3(2). Heterologous expression of genes absA2 from Streptomyces ghanaensis ATCC14672 and lndYR from genome Streptomyces globisporus 1912 decreased synthesis of antibiotic. The study results indicate the presence of homologs of these genes in chromosome of S. nogalater, their possible participation in regulation of nogalamicin biosynthesis, and provide us with a possibility for genetic design of the strains with higher synthesis of this antibiotic.
Destruction of mixture of tri-hexa-chlorinated biphenyls by Rhodococcus genus strains by D. O. Egorova; V. A. Demakov; E. G. Plotnikova (pp. 599-606).
Destruction of polychlorinated biphenyls (PCBs) by strain-destructors Rhodococcus sp. B7a and Rhodococcus sp. G12a has been studied. It was shown that these strains destruct 78–95% of PCB mixture containing tri-hexa-chlorinated biphenyls. Rhodococcus destruct all components of the mixture of tri-, tetra-, penta-, and hexa-chlorinated biphenyls without accumulation of toxic chlorinated metabolites. The studied bacteria destruct PCB that are the most stable for oxidation, such as 2,5,2′,5′-CB; 3,4,3′,4′-CB; and 2,4,5,2′,4′,5′-CB. The most perspective strains are R. rubber P25, Rhodococcus sp. B7a and Rhodococcus sp. G12a whose metabolic potential can be used for biotechnological refinement of the environment from highly toxic pollutants.
Biohydrometallurgical technology of copper recovery from a complex copper concentrate by M. I. Muravyov; N. V. Fomchenko; T. F. Kondrat’eva (pp. 607-614).
Leaching of sulfide-oxidized copper concentrate of the Udokan deposit ore with a copper content of 37.4% was studied. In the course of treatment in a sulfuric acid solution with pH 1.2, a copper leaching rate was 6.9 g/kg h for 22 hours, which allowed extraction of 40.6% of copper. At subsequent chemical leaching at 80°C during 7 hours with a solution of ferric sulfate obtained after biooxidation by an association of micro-organisms, the rate of copper recovery was 52.7 g/kg h. The total copper recovery was 94.5% (over 29 hours). Regeneration of the Fe3+ ions was carried out by an association of moderately thermophilic microorganisms, including bacteria of genus Sulfobacillus and archaea Ferroplasma acidiphilum, at 1.0 g/L h at 40°C in the presence of 3% solids obtained by chemical leaching of copper concentrate. A flowsheet scheme of a complex copper concentrate process with the use of bacterial-chemical leaching is proposed.
Corrosive activity of natural microbial associations at various conditions of cultivation by V. B. Rodin; S. K. Zhigletsova; N. A. Zhirkova; N. V. Aleksandrova; V. A. Chugunov; V. P. Kholodenko (pp. 615-620).
Influence of microbial associations isolated from different ecological niches on corrosion of mild steel was changed depending on composition of medium and aeration regime. Both decrease and increase in corrosion losses were observed, which indicated that the subdivision of microorganisms into destructors and passivators of corrosion is merely conventional.
Metabolic changes in wheat (Triticum aestivum L.) plants under action of bioregulator stifun by O. I. Yakhin; A. A. Lubyanov; I. A. Yakhin; V. A. Vakhitov; R. I. Ibragimov; M. S. Yumaguzhin; Z. F. Kalimullina (pp. 621-626).
Under action of growth-stimulating concentrations of bioregulator stifun on wheat plants, an increase of functional activity of nucleoli of meristematic cells; contents of lectin (wheat germ agglutinin); and activity of proteinases, tripsin inhibitors, and ATPase activity was established. The pool of free amino acids was increased under bioregulator use. Levels of methionine, phenylalanine, cysteine, lysine, leucine and tyrosine were increased. It is likely that stifun could activate protein biosynthesis in wheat plants.
Immunochromatographic technique for express determination of ampicillin in milk and dairy products by N. A. Byzova; E. A. Zvereva; A. V. Zherdev; B. B. Dzantiev (pp. 627-634).
An immunochromatographic method for determination of β-lactam antibiotic ampicillin has been developed. The method is based on the competitive interaction between antibiotic molecules contained in the sample and protein conjugate of penicillin immobilized on a membrane for binding with specific antibodies labeled with colloidal gold, which occurs during movement of the sample to be tested and reagents along the membrane. The completion of the test system ensures control of exceeding the maximum permissible content of the antibiotic in milk and dairy products (10 ng/mL). The possibility of testing milk, raw milk, and dairy products for 10 minutes at room temperature without sample pretreatment has been demonstrated.
Keywords: ampicillin; immunoassay; immunochromatography; colloidal gold; milk; dairy products
Molecularly imprinted hydrophilic polymer sorbents for selective sorption of erythromycin by N. M. Ezhova; I. S. Garkushina; O. A. Pisarev (pp. 635-639).
New hydrophilic polymer sorbents comprising reactionary sites which are complementary to a molecule of antibiotic erythromycin were synthesized by the method of molecular imprinting. A series of similar sorbents without reactionary sites was used for comparison of sorption characteristics. Sorption of erythromycin on both types of polymer sorbents synthesized was studied in a wide range of pH and ionic strength. Selectivity of erythromycin sorption on molecularly imprinted cross-linked polymers was shown to depend on the specific interaction of target molecule with polymer matrix. This type of sorbent is perspective for the development of antibiotic purification directly from a culture medium Saccharopolyspora erythreus.
Effect of polysaccharides on biological activity of human lactoferrin by N. M. Mestechkina; O. A. Bezborodova; A. V. Il’ina; A. N. Levov; S. Yu. Kleimenov; E. R. Nemtsova; R. I. Yakubovskaya; V. D. Shcherbukhin; V. P. Varlamov (pp. 640-647).
The influence of neutral and ionic polysaccharides on the antioxidant (AOA) and detoxifying activities of lactoferrin (LF) and the duration of its circulation in the body was studied. In addition to natural polymers, we studied chitosan synthetic derivatives with different functional groups. On the basis of AOA test, five polysaccharides were selected. The study of the detoxifying effect of LF in two models of induced toxicity revealed polysaccharides that maintained or increased the detoxifying activity of LF. We established that the formation of a complex of lactoferrin with two galactomannans and succinyl chitosan caused positive changes in LF properties: the detoxifying activity of the protein remained unchanged or increased, whereas its elimination from the body was decelerated.