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Applied Biochemistry and Microbiology (v.43, #2)
2-C-methylerythritol phosphate pathway of isoprenoid biosynthesis as a target in identifying new antibiotics, herbicides, and immunomodulators: A review by Yu. V. Ershov (pp. 115-138).
Specific inhibitors of 2-C-methylerythritol phosphate pathway (MEP-pathway), including compounds obtained based on its metabolites, may compose a new class of antibiotics combining high efficiency and low toxicity. MEP-pathway of isoprenoid biosynthesis is a promising target in identifying new herbicides, immunomodulators, and other physiologically active compounds.
Flavonoids: Efficient protectors of glucose-6-phosphate dehydrogenase from ultrasonic cavitation-induced inactivation by E. I. Karasyova; V. P. Kurchenko; D. I. Metelitza (pp. 139-149).
Seven structurally diverse flavonoids have been shown to decrease glucose-6-phosphate dehydrogenase (G6PDH) inactivation in 0.1 M phosphate buffer (pH 7.4), induced by exposure to a high temperature (44°C), or by a low-frequency ultrasound (27 kHz, 60 Wt/cm2). The activity of the compounds was assessed by their ability to change effective first-order rate constants characterizing the total (thermal and ultrasonic), thermal, and ultrasonic inactivation of 2.5 nM G6PDH (k in, k*in, and k in(us), respectively). The value dependences of these constants on flavonoid concentrations (0.01–50 μM) were obtained. Rank order of potency exhibited by the compounds in protecting G6PDH appeared as follows: hesperidin > morin > silibin > naringin = quercetin > kampferol ≫ astragalin. The data obtained confirm the crucial role of free radicals formed in the field of ultrasonic cavitation (HO· and O 2 ·− in G6PDH inactivation in solutions.
Immobilization of ovomucoid on chitosan by I. M. Shanazarova; L. I. Valuev; I. L. Valuev; T. A. Valueva; I. V. Obydennova (pp. 150-152).
The inhibitory activity of ovomucoid from duck egg white, immobilized on chitosan with the use of glutaraldehyde or carbodiimide as cross-linking agents, was studied. Glutaraldehyde proved to be a more preferable cross-linking agent than carbodiimide. When chitosan is used as a protein carrier, the possibility of shifting the pH optimum of these compounds should be taken into account.
Properties of cotton inorganic pyrophosphatase by B. O. Beknazarov; M. N. Valikhanov (pp. 153-158).
The activity of inorganic pyrophosphatase and pyrophosphate content were studied in developing and germinating cotton seeds. It was shown that the content of pyrophosphate in germinating seeds reached its maximum value after two days of their development, and the activity of inorganic pyrophosphatase, one day after the beginning of seed bud formation. The low pyrophosphatase activity of dormant seeds increased during their germination under open-ground conditions, reaching its maximum on day 6–7. Properties of partly purified pyrophosphatase from three-day-old cotton seedlings grown under laboratory conditions were studied.
Properties of chitinolytic enzymes from the hepatopancreas of the red king crab (Paralithodes camtschaticus) by V. Yu. Novikov; V. A. Mukhin; K. S. Rysakova (pp. 159-163).
Our study confirms the presence of chitinolytic, chitosanolytic, and deacetylase activities in the hepatopancreas of the red king crab, related to the specific diet of this species. The maximum rate of chitin/chitosan hydrolysis by an enzyme preparation from crab hepatopancreas occurs at 36.5–37.0°C. Two pH optimums have been found for the enzymatic reaction under mildly alkaline and acidic conditions for both exo-and endochitinase activities. The enzyme preparation is most affine to partly deacetylated chitin with an acetylation degree within 40–50%.
Production of hydrolases by lactic acid bacteria and bifidobacteria and their antibiotic resistance by G. I. Novik; N. I. Astapovich; N. E. Ryabaya (pp. 164-172).
It was demonstrated that bifidobacteria and lactic acid bacteria B. adolescentis and Lactobacillus sp. synthesized extracellular enzymes cleaving glycoside bonds in the molecules of dextran, pectic acid, and soluble starch. The maximal production of extracellular β-galactosidase by B. adolescentis 91-BIM and 94-BIM at a rate of 0.08 and 0.03 U/mg per h was observed during the exponential growth phase at 5 and 12 h of cultivation, respectively. The cultures of bifidobacteria retained 60–70% of β-galactosidase and α-amylase activities after six months of storage. The bifidobacterium strains studied were resistant to amphotericin and aminoglycosides (gentamicin, kanamycin, and netromycin). The lactam antibiotics (ampicillin, benzylpenicillin, bicillin 3, bicillin 5, and carbenicillin), the preparations inhibiting protein synthesis at the level of ribosomes (lincomycin), RNA polymerase inhibitors (rifampin), cephalosporin, and Maxipime inhibited the growth of bifidobacteria. Rifampin, erythromycin, amphotericin, Maxipime, Fortum, doxycycline, levomycetin, streptomycin, and the aminoglycosides netromycin, gentamicin, and kanamycin did not have an effect on the growth of Lactobacillus sp., whereas semisynthetic derivatives of penicillin, carbenicillin and ampicillin, inhibited its growth as well as Oxamp and lincomycin. The lactam antibiotics benzylpenicillin, bicillin 3, and bicillin 5 inhibited the growth of lactic acid bacilli by 30–90%.
Immobilization of Rhodococcus ruber strain gt1, possessing nitrile hydratase activity, on carbon supports by A. Yu. Maksimov; Yu. G. Maksimova; M. V. Kuznetsova; V. F. Olontsev; V. A. Demakov (pp. 173-177).
Rhodococcus ruber strain gt1, possessing nitrile hydratase activity, was immobilized by adsorption on carbon supports differing in structure and porosity. The adsorption capacity of the supports towards cells, the substrate of the nitrile hydratase reaction (acrylonitrile), and the product (acrylamide) was studied. Also, the effect of immobilization on nitrile hydratase activity of bacteria was investigated, and the operational stability of the immobilized biocatalyst was determined. It was shown that crushed and granulated active coals were more appropriate for immobilization than fibrous carbon adsorbents.
Search for lactate oxidase producer microorganisms by M. B. Kupletskaya; M. V. Sukacheva; A. V. Kurakov; A. I. Netrusov (pp. 178-181).
Using the method of enrichment cultures, eight lactate oxidase producer strains of the fungus Geotrichum candidum were identified. The microorganisms were isolated from diverse specimens of fermented vegetables and manure. Variation in (1) the content of glucose and lactate and (2) the degree of aeration made it possible to attain lactate oxidase activities of up to 130–140 U per 11 grown medium containing microbial cells.
A study of the competitive properties of the aluminum-tolerant strain Rhizobium leguminosarum bv. trifolii 9-4A by the antibiotic resistance method by A. A. Shirokikh; I. G. Shirokikh (pp. 182-186).
The virulence, competitive ability, and symbiotic efficiency of 2 Rhizobium leguminosarum bv. trifolii strains—the wild aluminum tolerant strain 9-4A and the commercial strain 348a—were compared when introducting their variants marked with antibiotic resistance into the rhizosphere of red clover (Trifolium pratense L.) plants. High virulence and competitive ability of the strain tolerant to aluminum was demonstrated by a concurrent inoculation of the seeds with these two strains. The resistance acquisition by the commercial strain was accompanied by a decrease in its symbiotic efficiency. Presumably, the resistant variant of aluminum-tolerant isolate retains its symbiotic properties due to its adaptation to acidity factors at the level of membrane function.
Synthesis of bacteriochlorophyll a by the purple nonsulfur bacterium Rhodobacter capsulatus by E. V. Patrusheva; A. S. Fedorov; V. V. Belera; I. G. Minkevich; A. A. Tsygankov (pp. 187-192).
The ability of purple nonsulfur bacteria Rhodobacter capsulatus B10 to synthesize bacteriochlorophyll under phototrophic and dark conditions was studied. The modes for cultivation in the dark with oxygen limitation in a continuous culture at D = 0.1 h−1 were selected. The yield of biomass reached 20 g/l; the bacteriochlorophyll a output of the process amounted to 16.6 mg/l h−1.
Measurement of the content of the osmoprotectant ectoine in methylotrophic bacteria by means of normal-phase high performance liquid chromatography by B. Ts. Eshinimaev; I. S. Tsyrenzhapova; V. N. Khmelenina; Yu. A. Trotsenko (pp. 193-196).
Detection and quantitative analysis of ectoine in bacterial biomass were performed by normal-phase high performance liquid chromatography with ultraviolet detection at 230 nm. Quantitative analysis was not hindered by glutamate and sucrose accumulation in bacteria. Measurement of ectoine concentration in haloalkaliphilic methanotrophs Methylobacter marinus 7C and Methylomicrobium alcaliphilum 5S showed that ectoine accumulation reached maximum (5 and 12% of dry cell weight) in the presence of NaCl at concentrations of 4 and 6%, respectively.
Consumption of volatile organic compounds by alcaliphilic microorganisms by I. V. Ulezlo; A. M. Bezborodov (pp. 197-200).
It has been shown that various microbial species used in bioreactors for purification of air from volatile organic impurities can grow at alkaline pH values consuming the xenobiotics as sole carbon sources. The alkali tolerance depends on the carbon source. The alkaline pH of the medium reduces the foreign microbial population restricting the potential of the bioreactor.
Consumption of hydrocarbons by psychrotolerant degrader strains by I. S. Andreeva; E. K. Emel’yanova; S. E. Ol’kin; I. K. Reznikova; S. N. Zagrebel’nyi; V. E. Repin (pp. 201-206).
Oil-oxidizing microorganisms have been sampled in various regions of Siberia and used in strain associations, which degrade n-alkanes of oil from various fields by 64–92% after 6 days of growth in a wide temperature range. These strains are salt-tolerant and psychrotolerant. They are compatible with aboriginal soil microflora. Promising results have been obtained in experiments on growing plants on oil-polluted soil purified with a biodegrader of this series.
Spontaneous variability of glucose oxidase-producing fungus Penicillium adametzii LF F-2044 by R. V. Mikhailova; L. A. Zhukovskaya; A. G. Lobanok (pp. 207-210).
The glucose oxidase-producing fungus Penicillium adametzii LF F-2044 was studied for natural variability. Four variants of the fungus differed in morphological characteristics and glucose oxidase synthesis. The synthesis of extracellular glucose oxidase and the productivity of morphological variants P. adametzii LF F-2044.1 and P. adametzii LF F-2044.2 were 127–146 and 95–159% higher, respectively, than the control. Highly active morphological variants of the fungus were chosen for further selection experiments.
Operating characteristics of solid-state fermentation bioreactor with air pressure pulsation by J. Liu; D. B. Li; J. C. Yang (pp. 211-216).
The development of solid state fermentation (SSF) technology is very important to the production of cellulase and ultimately to the utilization of natural cellulose. However, inadequate dissipation of heat generated by biological activities has prevented solid-state fermentation from large-scale applications. The paper deals with the development of a novel SSF bioreactor with air pressure pulsation. By developing a measurement and control system under the Virtual Instrument (VI) concept, the performance of the SSF bioreactor with pressure pulsation was studied by cultivating Trichoderma koningii in solid medium made of wheat bran and corncob. The cooling effects of pressure pulsation on solid porous beds are discussed. Experimental results show that pressure pulsation enhances medium moisture evaporation, and hence, heat dissipation. Furthermore, through changing the pressure pulsation directions, it is able to mitigate the temperature gradients in the bioreactor. To sum up, pressure pulsation can provide the microbes with a growing environment at optimal temperature and medium water content.
Active oxygen species in pea seedlings during the interactions with symbiotic and pathogenic microorganisms by G. G. Vasil’eva; A. G. Glyan’ko; N. V. Mironova; T. E. Putilina; G. B. Luzova (pp. 217-221).
The level of active oxygen species (AOS)—superoxide anion radical (O 2 ·− ) and hydrogen peroxide (H2O2)—in pea (Pisum sativum L.) cultivar Marat seedlings was studied upon their inoculation with symbiotic (Rhizobium leguminosarum bv. viceae strain CIAM 1026) and pathogenic (Pseudomonas syringae pv. pisi Sackett) microorganisms. Different patterns of the changes in AOS in pea seedlings during the interactions with the symbiont and the phytopathogen were recorded. It is assumed that O 2 ·− and H2O2 are involved in the defense and regulatory mechanisms of the host plant.
The effect of melamine salt of bis(oxymethyl)phosphinic acid (melafen) on the growth processes and plasma membrane function in potato tuber cells by E. P. Ladyzhenskaya; T. A. Platonova; A. S. Evsyunina; S. G. Fattakhov; N. P. Korableva; V. S. Reznik (pp. 222-226).
The effects of a new synthetic growth regulator, preparation melafen, on the growth processes in potato plant tubers and the H+-ATPase activity in cell plasmalemma were studied. It was demonstrated that melafen could both stimulate and inhibit the growth of potato tubers depending on its concentration and the physiological state of the tubers. It is likely that one of the manifestations of melafen action is its influence on the division and extension of apical meristem cells. The growth stimulation caused by melafen is connected with modifications of the plasmalemma of potato tuber cells, namely, the activation of H+-ATPase and increase in the membrane proton permeability.
Products of the photolysis of 3,6-dichloropicolinic acid (the herbicide lontrel) in aqueous solutions by E. A. Saratovskikh; O. V. Polyakova; O. S. Roshchupkina; A. T. Lebedev (pp. 227-231).
We studied the composition of products of the photochemical degradation of 3,6-dichloropicolinic acid (DCPA), the active principle of Lontrel, a herbicide broadly used in agriculture. Ultraviolet irradiation (mimicking the natural sunlight action) did not degrade DCPA completely to environmentally safe products. The rate of DCPA degradation was notably lower when distilled water was replaced by river water and even lower in sea water. Chromatomass spectrometry revealed 9 compounds among the photolysis products, in addition to undegraded DCPA.