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Applied Biochemistry and Microbiology (v.46, #4)
Biodiesel-fuel: Content, production, producers, contemporary biotechnology (Review) by E. P. Feofilova; Ya. E. Sergeeva; A. A. Ivashechkin (pp. 369-378).
The necessity of expanding studies on producing renewable biofuel is reviewed. Special attention is given to biodiesel, the history of its creation, and its advantages and disadvantages in comparison with diesel-fuel. The main part of the review is devoted to an analysis of diesel biofuel on the basis of bacterial lipids, filamentous fungi, yeasts, plants, photo- and heterotrophic algae. Biodiesel on the basis of filamentous fungi is studied in detail and the possibility of creation of the most perspective biotechnology using these producers is grounded. The contemporary state of biotechnology in Russia is discussed in connection with the development of energetics based on renewable biofuels.
A study of the catalytic properties of the nitrile hydratase immobilized on aluminum oxides and carbon-containing adsorbents by Yu. G. Maksimova; V. A. Demakov; A. Yu. Maksimov; G. V. Ovechkina; G. A. Kovalenko (pp. 379-384).
The nitrile hydratase isolated from Rhodococcus ruber strain gt1, displaying a high nitrile hydratase activity, was immobilized on unmodified aluminum oxides and carbon-containing adsorbents, including the carbon support Sibunit. The activity and operational stability of the immobilized nitrile hydratase were studied in the reaction of acrylonitrile transformation into acrylamide. It was demonstrated that an increase in the carbon content in the support led to an increase in the amount of adsorbed enzyme and, concurrently, to a decrease in its activity. The nitrile hydratase immobilized on Sibunit and carbon-containing aluminum α-oxide having a “crust” structure displayed the highest operational stability in acrylonitrile hydration. It was shown that the thermostability of adsorbed nitrile hydratase increased by one order of magnitude.
Thermal inactivation of free and immobilized inulinase by V. G. Artyukhov; T. A. Kovaleva; M. G. Kholyavka; L. A. Bityutskaya; M. V. Grechkina (pp. 385-389).
Thermal inactivation of the Kluyveromyces marxianus inulinase in a free form and immobilized on VION KN-1 cation exchange fiber was studied. Atomic force microscopy demonstrated an oligomeric structure of this enzyme, composed of two subunits differing in their size. It was assumed that the intersubunit contacts were destroyed at 60°C, and the inulinase molecule dissociated into two monomers located separately.
Activity dynamics of potential marker enzymes of Serratia marcescens cytoplasm and periplasm by L. M. Bogomol’naya; M. N. Filimonova (pp. 390-394).
Activity dynamics of glucose-6-phosphate dehydrogenase, alkaline phosphatase, β-galactosidase and β-lactamase in the course of growth and development of Gram-negative bacteria Serratia marcescens was studied. Glucose-6-phosphate dehydrogenase can serve as a marker of cytoplasm and be also used as a marker of plasma membrane continuity. Alkaline phosphatase is a marker of periplasm. Glucose-6-phosphate dehydrogenase, β-lactamase and β-galactosidase can be additionally used as markers of the outer membrane continuity of microbial cells.
Genetic improvement of technological characteristics of starters for fermented milk products by H. G. Hovhannisyan; A. A. Barseghyan; N. G. Grigoryan; A. V. Topchyan (pp. 395-399).
Possibility for improvement of technological characteristics of lactobacilli using mutations of resistance to rifampicin (rif r ) and streptomycin (str r ) was studied. Using starter model of Narine Lactobacillus acidophilus INMIA-9602 Armenian diet milk product, it was showed that a possibility for selecting strains with increased rate of milk fermentation and acid production is higher in Rifr and Strr mutants induced by nitrosoguanidine than in cultures sensitive to antibiotics. The milk products obtained using Rifr and Strr strains had high viscosity, improved texture, increased amount of alive cells and good organoleptic features.
Some aspects of xylose isomerase constitutive biosynthesis in Arthrobacter nicotianae by L. I. Sapunova; I. O. Tamkovich; A. G. Lobanok (pp. 400-404).
The specific features of biosynthesis of the cell-bound xylose isomerase by the actinobacterium Arthrobacter nicotianae BIM V-5 were studied. It was demonstrated that the constitutive synthesis of this enzyme in the studied bacteria, not subject to catabolite repression, was inhibited by xylulose, an intermediate product of xylose utilization and the final product of its enzymatic isomerization. Short-term experiments demonstrated that xylulose at a concentration of 0.005% almost completely repressed the xylose isomerase synthesis in A. nicotianae. This effect was independent of the time moment when the repressor was added to the cultivation medium and was not associated with its influence on the catalytic activity of the enzyme.
Features of biosynthesis of chitinolytic enzymes by Streptomyces griseus var. streptomycini by S. V. Avramenko; V. A. Galynkin (pp. 405-408).
The previously selected strain Streptomyces griseus var. streptomycini is able to hydrolyze colloid as well as crystal forms of chitin. During the submerged cultivation in the medium with crystal chitin, the chitinase activity achieved the maximal value after 46–50 h of culturing. Use of colloid chitin as an inductor allowed increasing the chitinolytic activity by 33%. Adding of mannose to the medium increased the chitinase activity of the producer by two times. It has been shown that the chitinase biosynthesis bears an inducible nature.
Heterologous interferons synthesis in yeast Pichia pastoris by M. V. Padkina; L. V. Parfenova; A. E. Gradoboeva; E. V. Sambuk (pp. 409-414).
The HuIFNA16, HuIFNB1, and BoIFNG genes encoding human α16, β-interferons and bovine γ-interferon were cloned under the control of the yeast Pichia pastoris AOX1 gene promoter. The yeast strains producing heterologous interferons intracellularly and extracellularly were constructed. There was no effect of high level of heterologous protein synthesis on the yeast P. pastoris cell growth, unlike yeast Saccharomyces cerevisiae. The considerable part of the heterologous interferons was detected in the yeast P. pastoris soluble protein fraction but not in the “inclusion bodies.” The treatment of human β-interferon with endoglycosidase H showed that protein was expressed in glycosylated and unglycosylated forms. On the strength of these data, the hypothesis was suggested that the more effective heterologous gene expression in yeast P. pastoris and enhanced resistance of the methylotrophic yeast to negative effects of recombinant proteins was due to the special features of its metabolism.
Co-expression of xylose reductase gene from Candida shehatae and endogenous xylitol dehydrogenase gene in Saccharomyces cerevisiae and the effect of metabolizing xylose to ethanol by Jinxin Zhang; Min Yang; Shen Tian; Yazhen Zhang; Xiushan Yang (pp. 415-420).
The inability oft Saccharomyces cerevisiae to utilize xylose is attributed to its inability to convert xylose to xylulose. Low xylose reductase (XR) and xylitol dehydrogenase (XDH) activities in S. cerevisiae are regarded as the reason of blocking the pathway from xylose to xylulose. We had found that Candida shehatae could also be another source for XR gene except Pichia stipitis in the previous study. In this study, we tried to investigate if the expressed XR from C. shehatae could work with the over-expressed endogenous XDH together to achieve the same goal of converting xylose to ethanol in S. cerevisiae. The XR gene (XYL1) from C. shehatae and endogenous XDH gene (XYL2) were both cloned and over-expressed in host S. cerevisiae cell. The specific enzyme activities of XR and XDH were measured and the result of fermentation revealed that the new combination of two enzymes from different sources other than P. stipitis could also coordinate and work with each other and confer xylose utilization ability to S. cerevisiae.
Bioconversion of glycyrrhizinic acid in liquorice into 18-β-glycyrrhetinic acid by Aspergillus parasiticus Speare BGB by J. Wang; Q. Sun; P. Gao; J. F. Wang; C. Xu; Q. L. Sun (pp. 421-425).
A filamentous fungi strain, Aspergillus parasiticus Speare BGB, producing (β-glucuronidase was screened to transform glycyrrhizinic acid (GL) in liquorice into 18-β-glycyrrhetinic acid (GA). Under the following cultivate conditions in shake flask, 1% GL (purity 30%), medium capacity 40% of flask, the initial pH value at 4.5, cultivate temperature of 32°C, inoculum size of 5% and culturing time for 96 hs. The bioconversion ratio of GL into GA could reach 95%. A variety of parameters of submerged state fermentation, including the growth characteristics of A. parasiticus Speare BGB, the change amount of GL and GA, and the activity of β-glucuronidase, were monitored simultaneously. GA was separated and purified by macroporous resin, silica gel column chromatography followed by recrystalization with the final purity over 98%. Purified product was identified as GA by the infrared absorption spectrum, molecular weight, and nuclear magnetic resonance. This study provided a new and efficient approach of obtaining GA by microbial transformation.
Antimicrobic and hemolytic activity of low-molecular metabolits of brown seaweed Laminaria cichorioides (Miyabe) by N. I. Gerasimenko; E. L. Chaykina; N. G. Busarova; M. M. Anisimov (pp. 426-430).
Antimicrobial and hemolytic activity of ethanol extract of brown seaweed Laminaria cichorioides (Miyabe), its lipophilic fractions, various classes of substances of lipophilic fraction, such as chlorophylls, fucoxanthin, monogalactosyldiacylglycerols, digalactosyldiacylglycerols, sulfoquinovosyldiacylglycerols, and fatty acids were investigated. The antimicrobial activity was studied by means of yeast cells Safale S-04 and Candida albicans KMM 455, fungi Aspergillus niger KMM 4634 and Fusarium oxysporum KMM 4639, bacteria Staphylococcus aureus ATCC 21027 (gram-positive) and Escherichia coli ATCC 15034 (gram-negative) which demonstrated selective sensitivity to the studied substances. Hemolytic activity was investigated at concentrations of substances in the range of 0.2–200 μg/ml at different pH of erythrocyte suspension. All investigated substances caused hemolysis. The dependence of hemolytic activity of substances on pH of media was determined.
Activation of extracellular peroxidase of wheat roots under the action of xenobiotics by A. V. Chasov; V. Ya. Alekseeva; O. P. Kolesnikov; F. V. Minibayeva (pp. 431-437).
We studied the influence of xenobiotics of various chemical natures, including N,N’-dicyclohexylcarbodiimide, diethylstilbestrol, and chlorpromazine, on the activity of peroxidase, a redox-enzyme that participates in defense reactions of plants. It was shown that the influence of the studied xenobiotics on excised roots of wheat seedlings caused an increase in the permeability of plasmalemma for K+ and H+ and stimulated the activity of the extracellular peroxidase that forms the superoxide radical anion. It is assumed that the extracellular peroxidase can initiate the transformation of alien compounds on the cell surface, before their entrance into the cells.
The NADPH oxidase activity of pea seedling roots in rhizobial infection depending on abiotic and biotic factors by A. K. Glyan’ko; G. G. Vasil’eva; A. A. Ischenko; N. V. Mironova; A. L. Alekseenko (pp. 438-443).
The changes in NADPH activity was studied in the roots of 3–4-day-old etiolated pea (cultivar Aksaiskii usatyi) seedlings depending on plant inoculation with Rhizobium leguminosarum bv. viceae (strain CIAM 1026), adverse environmental factors (low temperature and high dose of a mineral nitrogen fertilizer), chemical substances (sodium nitroprusside and methyl viologen, or paraquat), and a biotic factor—the bacterium Escherichia coli (strain XL-1Blue). It was demonstrated that all exogenous factors increased the activity of microsomal NADPH oxidase. Rhizobial infection removed the activation caused by exogenous factors only in the case of high nitrogen content in the medium, thereby displaying an antagonistic effect. A synergistic action on the enzyme activity was observed in the variants with combined action of rhizobia + paraquat and rhizobia + E. coli. An increased NADPH oxidase activity coincided with a growth inhibition of pea seedling roots. The results are discussed from the standpoint of the roles of NADPH oxidase and reactive oxygen species in the legume-rhizobium symbiosis.
Galactomannan of the locoweed (Oxytropis lanata (Pallas) DC) seeds by D. N. Olennikov; A. V. Rokhin (pp. 444-448).
Galactomannan with a molecular weight of 1976 kDa was isolated by hot water extraction from the locoweed (Oxytropis lanata (Pallas) DC) seeds (yield, 3.68% of the seed weight); its solutions display high viscosity: [η] = 1697.7 ml/g and optical activity αD + 76.8°. The polysaccharide consists of mannose and galactose residues at a molar ratio of 1.36: 1. The backbone of galactomannan macromolecule is formed by 1,4-β-D-mannopyranose residues, 73.5% of which are substituted with single α-D-galactopyranose residues at C-6.
Preparation of magnetic latexes and their use for the immunodetection of microbial antigens by S. M. Kal’noi; I. V. Zharnikova; A. A. Zaitsev; A. I. Bondarenko; I. Yu. Borzdova; V. V. Ostapovich; A. A. Kurilova (pp. 449-457).
The possibility of detecting antigens of plague, tularemia, and brucellosis microbes with magnetic latex (ML)-based test systems has been demonstrated. MLs were prepared from latexes (polyacroleine microspheres, 1.2–1.8 ± 0.1 μm) by exposing the particles to a 25–35%-solution of ferrous sulfate for 0.5 h and then to a 15–25%-aqueous solution of ammonia for 0.5 h in a 100°C water bath and dehydrating after each operation. The possibility of preparing magnetic latex immunosorbents (MLIS) by ligand immobilization on ML and using them in magnetic latex ELISA (ML-ELISA) for the detection of microbial antigens was demonstrated. The detection limit in ML-ELISA equaled 102–103 microbial cells in 1 ml (cells/ml). Relative experimental error was not higher than 8%.
“Modern Problems of Physiology, Ecology, and Biotechnology of Microorganisms” All-Russia Symposium with International Participation (Moscow State University, Biological Faculty, December 24–27, 2009)
by N. N. Kolotilova; A. I. Netrusov (pp. 458-459).