


卷 53, 编号 1 (2017)
- 年: 2017
- 文章: 19
- URL: https://journals.rcsi.science/0003-6838/issue/view/9099
Erratum
Erratum to: “Possible mechanisms of germatranol influence on the thermal stability of wheat germs”



Article
Phycobiliproteins: Structure, functions and biotechnological applications
摘要
The functions of phycobiliproteins and phycobilisomes as photosynthetic antenna pigments in cells of cyanobacteria and a range of algae were considered. Achievements in the area of biological and natural sciences connected with study of phycobiliproteins are described. Sources and different possibilities of the practical application of these pigments in fluorescent spectroscopy, pharmacy, and biotechnology are analyzed.



Novel salt-resistant alkaline phosphatase from eggs of the sea urchin Strongylocentrotus intermedius
摘要
It was shown that the alkaline phosphatase (AP) isolated from eggs of the sea urchin Strongylocentrotus intermedius was a homodimer with a molecular mass of 150 kDa and that it exhibited maximal activity at a рН of 8.1–8.5 and a temperature of 45°С. Mg2+, Ca2+, and Mn2+ ions, as well as DTT, are activators of AP activity, while Zn2+, Cu2+, Cd2+, Pb2+, and Ni2+ ions, as well as EDTA, N-EMI, and p-CMB, inhibit its activity. The enzyme demonstrates unique salt resistance and can hydrolyze the substrate in seawater. It was shown by fluorescence methods and circular dichroism that an increase of the NaCl concentration above 1.0М caused noticeable changes in the secondary and tertiary structures of the protein and a decrease in enzyme activity. Analysis of the molecular masses of tryptic peptides conducted by mass spectrometry with the MASCOT program (which is based on the NCBI and SWISS-PROT databases) did not allow identification of the investigated protein. The uniqueness of the source and of the properties of the investigated AP, which were not characteristic for nonspecific AP, as well as the difficulties in primary structure identification with the fingerprinting technique, suggested that this enzyme was a nontypical AP with a novel structure.



Covalent immobilization of D-aminoacylase of strain Rhodococcus armeniensis AM6.1 and the characteristics of the biocatalyst
摘要
Immobilization of D-aminoacylase of the strain Rhodococcus armeniensis AM6.1 was carried out on the silochrome C-80 with a yield of enzymatic activity of 20%. The temperature and pH optima, thermal stability and dependence of thermal stability on pH for free and immobilized enzymes were compared. The possibility of using free and immobilized D-aminoacylases to produce D-amino acids from their racemic mixtures was demonstrated.



The effect of biguanide derivatives on antioxidant status during the development of oxidative stress
摘要
The intensity of free radical processes, activity of antioxidant enzymes (superoxide dismutase, catalase), and the content of low molecular weight antioxidants (reduced glutathione, citrate) in skeletal muscle and liver from rats with experimental rheumatoid arthritis administered with biguanide synthetic derivatives (2,4-dicarbomethoxyphenyl-biguanide and 4-methyl-phenyl biguanide) selected by Prediction of Activity Spectra for Substances (PASS), a computer program for the prediction of biological activity, were studied. The observed changes in the studied parameters toward the reference values under the effect of tested compounds can be explained by their antioxidant and protective properties during pathology, which are accompanied by oxidative stress. The results can be used for the development of new methods for the prevention and treatment of rheumatoid arthritis.



Molecular genetic analysis of determinants defining synthesis of 2,4-diacetylphloroglucinol by Pseudomonas brassicacearum BIM B-446 bacteria
摘要
Based on a full-sized sequence of the genome of Pseudomonas brassicacearum BIM В-446 bacteria, we determined the nucleotide sequence of the locus encoding the synthesis of the 2,4-diacetylphloroglucinol antibiotic. It was shown in the limits of a nucleotide sequence with 9087 bp size to be localized at open reading frames homologous (96–99% identical residues) to structural (phlA, phlC, phlB, phlD, phlE, and phlI) and regulatory (phlF, phlG, and phlH) genes of Pseudomonas brassicacearum and Pseudomonas fluorescens bacteria, which determine the production of 2,4-diacetylphloroglucinol. It emerged that closely related phl-operons differ by their environment. Thus, different genes were localized on the 3'-end. It was determined that inactivation of the phlA gene in P. brassicacearum BIM bacteria caused a loss of the ability to synthesize antibiotic and inhibited the growth of the phytopathogenic Fusarium culmorum, F. oxysporum, and Botrytis cinerea fungi; the antimicrobial activity was also decreased toward with fungal (Alternaria alternate) and bacterial pathogens (Pseudomonas syringae and Pectobacterium carotovorum). During inactivation of the phlF regulatory gene, which determines the synthesis of the phl-operon transcription repressor, the production of 2,4-diacetylphloroglucinol was increased. In contrast to the wild-type bacteria, phlF-mutants synthesized an antibiotic that was found in cultural liquid after 12 h of cultivation; its content reached the maximum in medium with saccharose as the carbon source.



Optimization of production conditions and 3D-structure modeling of novel antibacterial peptide of lantibiotic family
摘要
The effect of culture conditions (nutrient media, aeration, and temperature) of Staphylococcus warneri KL-1 on the growth and production of the antibacterial peptide warnerin was studied. The selected medium allowed the intensive development of S. warnerin KL-1 culture and a high level of peptide accumulation. It was demonstrated that the bacterial culture growth rate and warnerin production depended on the extent of aeration of the nutrient medium. The highest antibacterial activity (ABA) was achieved in culture liquid by the fed-batch cultivation. The amino acid sequence of the warnerin pure form was determined by structural bioinformatics analysis, and the 3D structure of this peptide was constructed. It was found that the peptide molecule contained three thioether cycles formed by one lanthionine residue and two methyl-lanthionine residues. According to the current classification of lanthipeptides, warnerin can be attributed to class I of lantibiotics.



Synthesis of high-molecular-mass polyhydroxybutyrate from methanol in Methyloligella halotolerans C2
摘要
The influence of the concentrations of carbon and energy sources (methanol) and nitrogen (NH4+) on the yield and molecular mass (Mm) of poly-β-hydroxybutyrate (PHB) synthesized by the novel methylotroph Methyloligella halotolerans C2 was investigated. It was shown that the maximum concentrations of NH4+ and methanol in the medium for PHB biosynthesis were 0.15 g/L and 1 ± 0.2 mL/L, respectively. A unique high-molecular (8000–10000 kDa) PHB was obtained with NH4+ and methanol concentrations of 0.12 g/L and 1.25 mL/L, respectively, in a fermenter. The main physicochemical and mechanical properties of the obtained bioplastic with a molecular mass of 10000 kDa were determined.



Alginate biosynthesis by Azotobacter bacteria
摘要
The ability of representatives of various species of the bacterial genus Azotobacter (A. chroococcum 7B, A. chroococcum 12B, A. chroococcum 12BS, A. agile 12, A. indicum 8, A. vinelandii 17, and A. vinelandii 5B) to alginate synthesis has been studied. It has been shown that all tested bacterial strains have this ability to different extents. Capsular alginate comprises from 2.6 to 32% of the total amount of synthesized alginate in various bacterial species. Strains that are able to active synthesis of alginate have been selected; the effect of the medium composition on their biosynthesis has been studied. The optimal conditions for alginate synthesis by the A. chroococcum 12BS producer strain include the presence of mannitol (40 g/L), yeast extract (1%), and low concentration of phosphates (KH2PO4—0.008 g/L, K2HPO4—0.032 g/L) in the medium; alginate production under these conditions is 4.5 g/L. The effect of aeration on polymer biosynthesis has been revealed: an increase in aeration causes an increase in alginate synthesis, while its decrease promotes the synthesis of poly-3-hydroxybutirate. It has been shown by IR spectroscopy that alginates obtained under various conditions of cultivation contain different ratios of residues of mannuronic and guluronic acids (M/G from 70/30 to 80/20) in the polymer chain and also differ in the amount of acetyl groups (from 10 to 25%) in the polyme structure.



Bacterial cellulose synthesized by Gluconacetobacter hansenii for medical applications
摘要
The properties of a polymer synthesized by the Gluconacetobacter hansenii strain GH-1/2008 were investigated. The studied bacterial cellulose polymer films are characterized by a mesh nanostructure composed of micro- and macrofibrils, a high water absorption capacity 556 ± 16.8%, and high strength and elasticity. Analysis of the spectrum recorded by 13С CP/MAS NMR spectroscopy showed that the bacterial cellulose synthesized by G. hansenii GH-1/2008 is a pure compound composed of Iα (65–70%) and Iβ (30–35%) allomorphs without any other impurities. It was found that the bacterial cellulose films with adsorbed antibiotics such as amoxiclav and fluconazole can be used as antibacterial and antifungal wound healing materials.



Possible pathways for destruction of polyaromatic hydrocarbons by some oil-degrading bacteria isolated from plant endosphere and rhizosphere
摘要
Six strains of oil-degrading bacteria isolated from the endosphere and rhizosphere of plants growing on oil polluted soils of the Irkutsk region were studied to determine the pathways for biodestruction of polyaromatic oil hydrocarbons. All strains were able to efficiently degrade polyaromatic hydrocarbons with the formation of pyrocatechin as a final product; strains 90, 108, and 112 additionally formed protocathechuic acid. The culture broth of the studied strains contained ferulic, n-coumaric, n-oxybenzoic, vanillic, and lilac acids, which probably represent metabolites of cinnamic alcohol, cinnamic aldehyde, and benzoic acid presenting in oil and metabolized by bacteria.



Selective leaching of zinc from copper-zinc concentrate
摘要
Biooxidation of copper-zinc concentrate with the use of consortia of mesophilic and moderately thermophilic acidophilic chemolithotrophic microorganisms was studied. Pyrrhotite, sphalerite, and chalcopyrite were the main sulfide minerals of the concentrate. The possibility in principal of complete selective leaching of zinc from sulfide concentrate coupled with minimal recovery of copper (less than 20%) was demonstrated. Selective leaching of zinc could be caused by galvanic interactions between minerals of the concentrate during the biooxidation. The results can be used as the basis for the development of the technologies for production of grade copper concentrate not containing zinc from sulfide copper-zinc concentrate obtained from refractory ores.



Modeling of anammox process with the biowin software suite
摘要
Mathematical modeling of the biotechnology for the removal of ammonium nitrogen from wastewater based on the anammox process was performed with the specialized BioWin software suite (EnviroSim Associates Ltd., Canada). Nitrogen removal by means of the transformation of ammonium nitrogen to molecular nitrogen was conducted in a continuous stirred bioreactor carrying both suspended and immobilized activated sludge. Both basic values of the kinetic and stoichiometric coefficients are incorporated in the BioWin software, and those that changed based on the results of the experimental studies were used for the calculations. The optimal temperature and dissolved oxygen concentration revealed by mathematical modeling were 35°C and 0.14 mg/L. The results obtained from calculations were similar to those obtained in the experiments. The calculated and experimental concentrations of ammonium, nitrites, and nitrates in the treated water were similar and comprised 10.7 and 11.7% of the initial concentration entering the bioreactor, respectively. The selected mathematical model possessed a high predictive ability for the calculation of biotechnologies based on the anammox process



Glycosylation and sulfation of 4-methylumbelliferone by Gliocladium deliquescens NRRL 1086
摘要
The aim of the study was to expand the substrate scope of Gliocladium deliquescens NRRL 1086 and generate coumarin glycosides using 4-methylumbelliferone (4-MU) as a substrate. The obtained results indicated that 4-MU can be metabolized to its glucoside (M1) and sulfate conjugate (M2), and the structures of the metabolites were elucidated by spectroscopic or enzymatic methods. Time course experiments detected that nearly 90% of 4-MU could be metabolized within 24 h, and the maximum yield of M1 could reach as high as 32%. Further tests revealed that the glucose concentration in the medium had little effect on the yield of M1 but time of 4-MU-adding could markedly affect the glycosylation procedure, and the favorable time to accumulate M1 was in the 12 or 24 h-old stage II culture, while in the 36 h-old or even older stage II culture, the substrate was almost metabolized to M2. The attempts to alter the ratio between M1 and M2 were performed by addition of quercetin and S-tetrahydroberberrubine or reduction of the sulfate concentration in the culture medium. Herein we describe, to the best of our knowledge, the first example of simultaneously microbial glycosylation and sulfation of coumarins.



Feasibility of oleaginous fungi isolated from soil samples of Saudi Arabia for mycodiesel production
摘要
As the demand for biofuels for transportation is increasing, it is necessary to acquire technologies that will allow affordable production of biodiesel. Conventional biodiesel is mainly produced from vegetable oil by chemical transesterification, but this product has relatively low yield and is competing with agricultural land that can be used for food production. In the present study, 14 filamentous fungi were isolated from different types of soil from Al-Hassa, Saudi Arabia. Nile red staining revealed that lipid bodies were present in 6 of the 14 fungal isolates. Lipid extraction showed that 3 fungi were able to accumulate lipid >20% (wt/wt) of their dry cell mass (0.59–2.40 g/L). The profile of fatty acids revealed a high content of oleic (C18:1, n9), palmitic (C16:0) and linoleic (C18:2) acids similar to conventional vegetable oils used for biodiesel production. Isolate RY4, with the highest lipid yield was identified as Mucor circinelloides based on morphological characteristics confirmed with 18S rRNA gene sequencing. Sequence data of nucleotides were obtained from DNA sequencing submitted to GenBank [GenBank: AB916546.1]. Certain oil compounds were determined by FTIR spectroscopy.



Anti-HCV protease of diketopiperazines produced by the Red Sea sponge-associated fungus Aspergillus versicolor
摘要
Hepatitis C virus (HCV) infection is a global problem due to the difficulties in developing a protective vaccine. In this work, we demonstrated that the ethyl acetate extract of the endophytic fungus Aspergillus versicolor exhibited significant activity against HCV NS3/4A protease with IC50 value of 30 μg/mL. The fungus was isolated from the Red Sea black sponge Spongia officinalis and identified by its morphology and 18S rDNA. Large-scale fermentation of the fungus followed by chromatographic purification with silica gel, Sephadex LH-20 and semipreparative HPLC of the active extract led to isolation of some known metabolites related to cyclodipeptides and the so-called diketopiperazines (DKPs). The DKP, cyclo(L-Tyr-L-Pro), displayed strong effect as HCV protease inhibitor with IC50 value of 8.2 μg/mL. A computational docking study of cyclo(L-Tyr-L-Pro) against HCV protease was used to formulate a hypothetical mechanism for the inhibitory activity of the active compound on the tested enzyme.



Enzyme-linked lectinosorbent assay of Escherichia coli and Staphylococcus aureus
摘要
In this study, we developed a microplate sandwich analysis of Escherichia coli and Staphylococcus aureus bacterial pathogens based on the interaction of their cell wall carbohydrates with natural receptors called lectins. An immobilized lectin-cell-biotinylated lectin complex was formed in this assay. Here, we studied the binding specificity of several plant lectins to E. coli and S. aureus cells, and pairs characterized by high-affinity interactions were selected for the assay. Wheat germ agglutinin and Ricinus communis agglutinin were used to develop enzyme-linked lectinosorbent assays for E. coli and S. aureus cells with the detection limits of 4 × 106 and 5 × 105 cells/mL, respectively. Comparison of the enzyme-linked immonosorbent assay and the enzyme-linked lectinosorbent assay demonstrated no significant differences in detection limit values for E. coli. Due to the accessibility and universality of lectin reagents, the proposed approach is a promising tool for the control of a wide range of bacterial pathogens.



A comparative analysis of the efficiency of bird and mammalian antibodies in HBsAg sandwich assay
摘要
The antigen-binding capacities of chicken and goat polyclonal antibodies and mouse monoclonal antibodies specific for the hepatitis B virus surface antigen were compared via enzyme immunoassay. It was shown that the use of both adsorbed and detecting chicken antibodies reduces significantly the analytical sensitivity of the sandwich method for the detection of this antigen. It was assumed that the reduced flexibility of IgY molecules hinders bivalent binding to antigen, which leads to the formation of more stable immune complexes.



Effect of some carbon nanomaterials on ethanol oxidation by Gluconobacter oxydans bacterial cells
摘要
The effect of carbon nanomaterials (carbon nanotubes, thermally expanded and pyrolytic graphite) on the bioelectrochemical activity of Gluconobacter oxydans bacterial cells was studied during sorption contact with nanomaterials. For bacterial immobilization, the surface of a working bioelectrode was modified via the application of bacterial suspension in the studied nanomaterial and chitosan. The bioelectrochemical electrode characteristics (the amplitude of generated potential, cyclic volt–ampere characteristics, resistance) were estimated before and in the process of bacterial interaction with ethanol (3-electrode measurement scheme). Modification of the spectral graphite electrode by carbon nanotubes allowed a decrease in the resistance of the charge transfer by 48% and an increase in the oxidation current on cyclic volt—ampere characteristics at a voltage of 200 mV by 21% as compared with nonmodified electrode. The thermally expanded and pyrolytic graphite increased the bioelectrode resistance to 4050 and 8447 Ohm cm2, respectively. Mathematical modeling demonstrated that from 75 to 100% of biomaterial (depending on the used nanomaterial) were involved in the process of electricity generation with the selected method of the bacterial immobilization. The use of data obtained during the development of microbial biosensors and electrodes of biofuel cells is discussed.


