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New Window Opens on the Secret Life of Microbes: Scientists Develop First Microbial Profiles of Ecosystems
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Applied Biochemistry and Microbiology (v.42, #3)
Hormones and hormone-like substances of microorganisms: A review by E. A. Tsavkelova; S. Yu. Klimova; T. A. Cherdyntseva; A. I. Netrusov (pp. 229-235).
Data from the literature on the ability of microorganisms to form plant hormones have been reviewed. The substances covered include abscisic acid, ethylene and other compounds with phytohormone-like properties (brassinosteroids, oligosaccharines) and analogues of animal neurotransmitters (biogenic amines). Pathways whereby the substances are metabolized and their effects on the development and activity (physiological and biochemical) of the microorganisms are considered. The role of phytohormones and hormone-like substances in the formation of association (microorganism-host) interactions are analyzed. The potential utilities of microorganisms producing hormones and hormone-like substances are discussed.
A comparative study of the thermal stability of formate dehydrogenases from microorganisms and plants by E. G. Sadykhov; A. E. Serov; N. S. Voinova; S. V. Uglanova; A. S. Petrov; A. A. Alekseeva; S. Yu. Kleimenov; V. O. Popov; V. I. Tishkov (pp. 236-240).
A comparative study of the thermostability of NAD+-dependent formate dehydrogenases (FDHs; EC 1.2.1.2) from both methylotrophic bacteria Pseudomonas sp. 101 and Moraxella sp. C1, the methane-utilizing yeast Candida boidinii, and plants Arabidopsis thaliana and Glycine max (soybean) was performed. All the enzymes studied were produced by expression in E. coli cells. The enzymes were irreversibly inactivated in one stage according to first-order reaction kinetics. The FDH from Pseudomonas sp. 101 appeared as the most thermostable enzyme; its counterpart from Glycine max exhibited the lowest stability. The enzymes from Moraxella sp. C1, C. boidinii, and Arabidopsis thaliana showed similar thermostability profiles. The temperature dependence of the inactivation rate constant of A. thaliana FDH was studied. The data of differential scanning calorimetry was complied with the experimental results on the inactivation kinetics of these enzymes. Values of the melting heat were determined for all the enzymes studied.
Isolation and properties of malate dehydrogenase from Meso-and thermophilic bacteria by A. T. Eprintsev; M. I. Falaleeva; M. A. Klimova; N. V. Parfenova (pp. 241-245).
A scheme of purification of malate dehydrogenase from Macromonas bipunctata strain D-405 and Vulcanithermus medioatlanticus DSM 14978T was developed. This scheme was used to obtain electrophoretically homogeneous enzyme preparations of the mesophilic bacterium M. bipunctata (specific activity, 26.9 ± 0.8 U/mg protein; yield, 10.9%) and the thermophilic bacterium V. medioatlanticus (specific activity, 5.0 ± 0.2 U/mg protein; yield, 19.2%). Using these high-purity enzymatic preparations, the physicochemical and regulatory properties of malate dehydrogenase were studied and the differences in kinetic characteristics and thermal stability of the preparations were determined.
Biosynthetic features and properties of xylose isomerases from Arthrobacter nicotianae, Escherichia coli, and Erwinia carotovora subsp. atroseptica by L. I. Sapunova; A. G. Lobanok; I. O. Kazakevich; E. A. Shlyakhotko; A. N. Evtushenkov (pp. 246-251).
The characteristics of xylose isomerase biosynthesis in the bacteria Arthrobacter nicotianae BIM B-5, Erwinia carotovora subsp atroseptica jn42xylA, and Escherichia coli HB101xylA have been studied. The bacteria produced the enzyme constitutively. Out of the carbon sources studied, D-glucose and D-xylose were most favorable for the biosynthesis of xylose isomerase in E. carotovora subsp. atroseptica, but the least appropriate in terms of the enzyme production efficiency in E. coli. Minimum and maximum levels of xylose isomerase formation in A. nicotianae were noted, respectively, during D-xylose and sucrose utilization. An addition to the D-xylose-containing nutrient medium of 0.1–1.5% D-glucose did not affect the enzyme synthesis in A. nicotianae, but suppressed it in Erwinia carotovora subsp. atroseptica (by 7% at the highest concentration) and Escherichia coli (by 63 and 75% at concentrations of 0.1 and 1.0%, respectively). The enzyme proteins produced by the bacteria exhibited the same substrate specificity and electrophoretic mobility (PAGE) as xylose isomerase A. nicotianae, although insignificant differences in the major physicochemical properties were noted.
A study of the mechanisms of probiotic effect of Bacillus subtilis strain 8130 by N. A. Ushakova; E. V. Kotenkova; A. A. Kozlova; A. V. Nifatov (pp. 252-257).
The wild-type Bacillus subtilis strain 8130 secreted metabolites that stimulated two to three times the growth of the test cultures of lactic acid bacteria. It exhibited endoglucanase activity that depended on the composition of nutrient medium. The addition of the product of two-stage culturing of B. subtilis 8130 to the diet of pigs (0.2% of fodder weight) made it possible to increase the daily weight gain by 19% and decrease the consumption of mixed fodder by 10%. Digestion of protein, fat, and other organic compounds increased by 3–4% and cellulose by 12%. It was shown that B. subtilis 8130 is a probiotic with targeted action stimulating digestion (primarily the digestion of cellulose). The enrichment of a dry-beer pellet with the product of solid-phase fermentation by bacillus (1 × 108 cells per gram dry pellet) allowed the pellet to entered into the diet of a calf (6% of the weight of fodder with probiotic), causing additional weight gain by 12% and a 10% economy of fodder consumption.
Raoultella planticola, a new strain degrading 2,4,5-trichlorophenoxyacetic acid by N. V. Zharikova; T. V. Markusheva; E. G. Galkin; V. V. Korobov; E. Yu. Zhurenko; L. R. Sitdikova; T. V. Kolganova; B. B. Kuznetsov; T. P. Turova (pp. 258-262).
A new strain that degrades the herbicide 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) was isolated from soil, which was exposed to factors related to the petrochemical industry. According to its physiological, biochemical, cultural, and morphological traits, together with the sequence of the 16S rRNA gene, the strain was identified as Raoultella planticola 33-4ch. The strain could consume 2,4,5-T as a sole source of carbon and energy. The amount of 2,4,5-T in the culture medium decreased by 51% after five days of incubation. Raoultella planticola 33-4ch consumes 2,4,5-T to produce 4-chlorophenoxyacetic, phenoxyacetic, and 3-methyl-2,6-dioxo-4-hexenoic acids.
Selection and characterization of active psychrotrophic microbial oil-degrading microorganisms by I. A. Pyrchenkova; A. B. Gafarov; I. F. Puntus; A. E. Filonov; A. M. Boronin (pp. 263-269).
The ability of 96 microbial strains degrading oil and 32 strains degrading polycyclic aromatic hydrocarbons (PAHs) to consume diesel fuel and oil at 4–6 and 24°C and at elevated NaCl concentrations was studied. The temperature range, salt tolerance, ability to produce biosurfactants, range of substrates, and antibiotic resistance were determined. The eleven most active oil-degrading and PAH-degrading strains were genotyped by a polymerase chain reaction with BoxA1R primers and a restriction analysis of ribosomal DNA amplicons. For six strains, the degree of oil degradation at 4–6°C was higher than at 24°C. For the most active strains, the degree of oil degradation in liquid mineral medium ranged from 15 to 26% at 24°C and from 28 to 47% at 4–6°C. An association of six of the strains degraded the oil by 46% at 24°C.
Microcalorimetric studies on the polyhydroxyalkanoates production of recombinant Escherichia Coli by L. Ruan; Y. Wang; Q. Yan; P. H. Yu (pp. 270-273).
The thermogenic curves of metabolism of two strains of Escherichia coli pUC19cab/XL-IBlue and XL-IBlue have been determined by using a LKB-2277 bioActivity Monitor and ampoule method at 37°C. pUC19cab/XL-IBlue was a recombinant E. coli strain bearing a foreign plasmid pUC19cab which brought the polyhydroxyalkanoates (PHAs) production. XL-IBlue was a host bacterium without any foreign DNA. Our studies reveal that the PHA production of recombinant E. coli has an apparent influence on their thermogenic curves of metabolism and therefore the initial time of PHAs production can be determined from these thermogenic curves.
Studies on the growth metabolism of Bacillus thuringiensis and its vegetative insecticidal protein engineered strains by microcalorimetry by J. Yao; Y. Liu; Y. Tuo; J. Zhu; X. Qin; J. Dong; S. Qu; Z. Yu (pp. 274-277).
The metabolic power-times curves of Bacillus thuringiensis and its vegetative insecticidal protein-engineered strains were determined at 30°C using a thermal activity monitor, air Isothermal Microcalorimeter, and ampoule method. From the power-times curves, the maximum power (P max) in the log phase, growth rate constant (k), generation times (t G), time of the maximum power (t max), heat effects (Q log) for log phase, and the total heat effect in 45 h (Q total) of. B. thuringiensis strains can be obtained. The results indicate that their power-times curves are different. The relationship between their metabolic power-times curves and character of bacteria metabolism, and thermokinetics and gene expression were analyzed and discussed. The character of the bacteria power-times curves reflected the physiologic character of gene expression. The microcalorimetric method proved to be a reliable and sensitive tool for the assessment of growth metabolism, heat output in bacteria and its engineered strains. The determination of the thermokinetic character is beneficial to the control of fermentation.
The effects of several factors on the growth of pure and mixed cultures of Azotobacter chroococcum and Bacillus subtilis by A. G. Kisten’; I. K. Kurdish; Z. T. Bega; I. Yu. Tsarenko (pp. 278-283).
We studied the effect of a clay mineral, palygorskite, on the physiological activity of Azotobacter chroococcum and the phosphate-mobilizing bacterium Bacillus subtilis, as well as their mixed cultures, under various oxygen supply conditions during the utilization of phosphorus from readily and poorly soluble compounds (K2HPO4 · 3H2O) and (Ca3(PO4)2), respectively. During cultivation of the bacteria in a nutrient medium with Ca3(PO4)2, the number of microorganisms was higher than that observed in a medium with K2HPO4. An increase in oxygen mass transfer in the nutrient medium was followed by a rise in the number of Bacillus subtilis cells and an inhibition of Azotobacter chroococcum growth. An addition of palygorskite (5 g/l) into the nutrient medium stimulated the growth of both bacteria and stopped the decreasing growth of Azotobacter chroococcum at high values of oxygen mass transfer. The number of Bacillus and, particularly, Azotobacter cells was two to five times lower in a mixed culture than in a monoculture. These differences were less significant during the cultivation of mixed cultures in medium with palygorskite.
The effect of various iron hydroxide concentrations on the anaerobic fermentation of sulfate-containing model wastewater by V. P. Stabnikov; V. N. Ivanov (pp. 284-288).
The addition of iron hydroxide and iron-reducing bacteria into a reactor for anaerobic processing of sulfate-containing wastewater was shown to decrease sulfate reduction and sulfide concentration, while increasing the total organic carbon (TOC) and methane production. The effect of iron (III) in sulfate-containing wastewater depended on its dose, which can be expressed as molar ratio Fe(III)/SO 4 2− . Sulfide concentration increased monotonically, reaching 91 and 45 mg/l after 15 days of processing at Fe(III)/SO 4 2− ratios of 0.06 and 0.5, respectively. However, soluble sulfide production was not observed at ratios equaling 1 and 2. At ratios of 0.06, 0.5, 1, and 2, the maximum rates of TOC removal were 0.75, 1.15, 1.39, and 1.55 g TOC/g of organic matter (OM) per 1 h. Methane production rates were 0.039, 0.047, 0.064, and 0.069 ml/g OM per 1 h, with the mean relative amounts of methane in the biogas being equal to 25, 41, 55, and 62%, respectively. These data can be applied to the development of new methods of anaerobic purification of sulfate-containing wastewater.
Bacterial leaching of manganese ores by A. V. Belyi; P. P. Pustoshilov; Yu. L. Gurevich; G. G. Kadochnikova; V. P. Ladygina (pp. 289-292).
Leaching of various types of ores, containing 12–30% manganese, by the thiobacterium Acidithiobacillus ferrooxidans was studied. Leaching of reduced ores (manganocalcite and manganiferous limestone) was mediated mainly by degradation of manganiferous minerals (by sulfuric acid produced in the course of bacterial oxidation of pyrite or sulfur). Bacterial treatment of the ores for 144 and 192 h allowed solubilization of 96–98% of manganese. Inoculation of bacteria into pulp with pyrite increased the rate of leaching of oxide ore (psilomelane) by 37%, and the degree of its extraction within 180 h increased from 80 to 97%.
A comparative study of the components of the antioxidant defense system during growth of the mycelium of a wild-type Neurospora crassa strain and mutants, white collar-1 and white collar-2 by N. N. Gessler; O. A. Leonovich; Ya. M. Rabinovich; M. N. Rudchenko; T. A. Belozerskaya (pp. 293-297).
A comparative study of the changes in the components of the antioxidant defense system (ADS), the activity of superoxide dismutase (SOD) and catalase and the level of extractable SH-groups, during the growth of wild-type and mutant (white collar-1 and white colar-2) Neurospora crassa strains was performed. Oxidative stress developing during spore germination and upon the transition to a stationary growth phase was accompanied in all strains by an increase in the level of extractable SH-groups and SOD activity, whereas the total catalase activity decreased during growth. However, in contrast to the wild-type strain, the activity of the catalase in the mutant strains wc-1 and wc-2 slightly increased upon the transition to the stationary phase. In the wc-2 mutant, SOD activity and the level of extractable SH-groups in the exponential growth phase were always lower than in the wild-type and wc-1 strains. The role of wc-1 and wc-2 genes in the level regulation of reactive oxygen species is discussed.
Extracellular proteinases from the phytopathogenic fungus Fusarium culmorum by E. V. Ievleva; T. A. Revina; N. N. Kudryavtseva; A. V. Sof’in; T. A. Valueva (pp. 298-303).
The growth of Fusarium culmorum fungus on a medium containing thermostable proteins from potato tubers was accompanied by the production of proteinases, exhibiting activity over a broad pH range (from 6.0–10.0). When studied by SDS-PAGE in the presence of β-mercaptoethanol, extracellular proteinases were represented by at least five species with a molecular weight of 30–60 kDa. Inhibitor analysis and studies of enzyme activities with synthetic substrates demonstrated that the culture liquid of Fusarium culmorum contained serine proteinases of various classes. The amount of subtilisin-like proteinases was the highest. A near-complete inhibition of the enzymes was caused by proteinaceous proteinase inhibitors from potato tubers. These data suggest that proteinases of the phytopathogen Fusarium culmorum serve as a metabolic target for natural inhibitors of potato proteinases.
Isolation and characterization of extracellular glucose oxidase from Penicillium adametzii LF F-2044.1 by A. N. Eryomin; M. V. Makarenko; L. A. Zhukovskaya; R. V. Mikhailova (pp. 304-311).
Hydroxides of magnesium and zinc, aluminum oxide, zinc phosphate, and co-precipitated Ca3(PO4)2 and Mg(OH)2 were efficient in binding extracellular glucose oxidase (GO) of P. adametzii LF F-2044.1 in a culture liquid filtrate (CLF). Basic Al2O3 was the most appropriate adsorbent for GO isolation from the CLF of the fungus. A GO isolation method was developed, which allowed for obtaining an enzyme with a high degree of purification. Spectral properties of the enzyme, its catalytic activity, and stability were characterized. The GO of P. adametzii LF F-2044.1 exhibited high pH stability, retaining activity within the range 4.5–9.0. The rate that GO-catalyzed D-glucose oxidation increased as the temperature increased (up to approximately 60°C). The catalytic activity and thermal stability of GO depended on its concentration in the medium. Under optimum conditions, the fractions GO-1 and GO-2 were characterized by K M values of 1.56 × 10−2 and 2.19 × 10−2 M, respectively; the corresponding values of k cat equaled 235.1 and 318.2 s−1.
Activity of NADP-dependent glyceraldehyde-phosphate dehydrogenase and phosphoenolpyruvate carboxylase in wheat leaves under water stress by I. I. Chernyad’ev; O. F. Monakhova (pp. 312-319).
The activities of NADP: glyceraldehyde-phosphate dehydrogenase (GAPDH), an enzyme complex comprising of phosphoglycerate kinase (EC 2.7.2.3) and glyceraldehyde-phosphate dehydrogenase (EC 1.2.1.13), and phosphoenolpyruvate carboxylase (PEPK; EC 4.1.1.31) in seedlings and leaves of wheat (Triticum aestivum L.) plants of the cultivars Mironovskaya 808 and Lutescens 758 have been compared under conditions of normal water supply, water deficiency, and subsequent rehydration. GAPDH activity, which determines the carbohydrate route of photosynthetic metabolism at the initial stages, is decreased by water stress to a greater extent than that of PEPK, on the activity of which non-carbohydrate metabolic pathways depend. Pretreatment of seedlings and mature plants with natural (6-benzylaminopurine) and synthetic (tidiazuron, kartolin-2, and kartolin-4) cytokinins attenuates the loss of enzyme activities during drought and facilitates their recovery within the period of rehydration; both effects are underlain by augmentation of reparation processes. The relative intensification of non-carbohydrate pathways of photosynthetic metabolism, observed under conditions of water deficiency, is accompanied by an increase in the osmotic pressure of cell sap. Possible mechanisms of this protector effect of cytokinin preparations are discussed.
Tetrapyrrole involvement in expression regulation of a nuclear gene of low-molecular-weight plastid protein ELIP by E. N. Pogul’skaya; N. P. Yurina; N. V. Karapetyan (pp. 320-325).
An inhibitor analysis was used for studying the tetrapyrrole role in the regulation of the expression of the nuclear gene encoding a low-molecular-weight protein, a stress plastid light-inducible protein ELIP. 2,2′-Dipyridyl and norflurazon were used as inhibitors. Experiments with dipyridyl demonstrated that tetrapyrroles were involved in the regulation of Elip gene expression, inhibiting it by ∼50%. Similar results were obtained when there was photodestruction of the chloroplasts, caused by a plant treatment with norflurazon. The results confirm the involvement of the chloroplasts in the regulation of the nuclear gene expression coding for plastid proteins. Tetrapyrroles are important contributors to this process.
Synthesis of galactomannan sulfates by N. M. Mestechkina; A. V. Egorov; V. D. Shcherbukhin (pp. 326-330).
The experimental conditions for the sulfation of legume galactomannans were found, which allow for the obtainment of polysaccharides with a high degree of substitution. Sulfate esters of four galactomannans of different composition (galactose content, 16.4–47.5%) were synthesized using the SO3-pyridine complex in dimethylformamide as a sulfating agent. The degree of substitution was as high as 1.4–1.8; it did not correlate with the content of galactose in the polysaccharides. It was found that the degree of sulfation depended on the reaction temperature in the range of 19–60°C.
Physicochemical properties of chitin-melanin and melanoprotein complexes from bee corpses by V. P. Kurchenko; T. A. Kukulyanskaya; I. I. Azarko; O. Yu. Zueva; R. G. Khizmatullin; V. P. Varlamov (pp. 331-334).
A technology for processing bee corpses and obtaining chitin-melanin and melanoprotein complexes has been developed. The obtained complexes of biopolymers were studied by the methods of absorption spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, thermogravimetry, and differential scanning calorimetry. The elemental composition of preparations was characterized. It was shown that the properties of the melanin-containing products of the processing of bee corpses are typical of chitin and melanin of animal origin. The results of EPR spectroscopy and thermal analysis are indicative of the diversity and structural complexity of the obtained products.
Binding of aromatic compounds to cornstarch polysaccharides by N. I. Krikunova; M. B. Terenina; E. L. Ruchkina; T. A. Misharina (pp. 335-338).
Sorption of aromatic compounds from aqueous solutions by cryotextures and suspensions of native cornstarches was studied by capillary gas chromatography. Acetophenone and benzyl alcohol were not sorbed by cryotropic-cornstarch gel and native-cornstarch suspension. A linear concentration dependence was found for aldehydes. Phenylethyl alcohol was characterized by a nonlinear concentration dependence. The presence of a benzene ring contributed to decreased binding (relative to the level characteristic of aliphatic compounds). The degree of binding depended considerably on the type of functional group in the aromatic compounds. Cryotextures were more potent than granules of native cornstarch in binding aromatic compounds.
Congratulations to professor Uldis Ernestovich Viesturs on his birthday
by M. Beker; D. Karklinya (pp. 339-340).