Genomic and proteomic profiles of Acholeplasma laidlawii strains differing in sensitivity to ciprofloxacin.

As a result of comparative analysis of complete genomes as well as cell and vesicular proteomes of A. laidlawii strains differing in sensitivity to ciprofloxacin, it was first shown that the mycoplasma resistance to the antibiotic is associated with the reorganization of genomic and proteomic profiles, which concerns many genes and proteins involved in fundamental cellular processes and realization of bacterial virulence.

Intranasal immunotherapy with M2 macrophage soluble factors in post-COVID hyposmia: A pilot study.

Olfactory dysfunction is an early marker of COVID-19 infection. However, individuals may develop chronic olfactory impairment for more than six months in 1-10 % of cases. The study's objective is to evaluate the efficacy and safety of intranasal immunotherapy using bioactive substances produced by M2 macrophages for the treatment of people with long-term post-COVID-19 hyposmia. Seven individuals with long-term persistent hyposmia (7 to 24 months), associated with PCR-confirmed coronavirus infection were evaluated for olfactory function at baseline, one, and six to twelve months after therapy. The intranasal inhalation of M2 macrophage conditioned medum (one time per day for 28-30 days) was well tolerated. Furthermore, olfactometry demonstrated that the patients restored their capacity to perceive (Kruskal-Wallis H test 14.123, p = 0.0009) and recognize odours (H = 11.674, p = 0.0029). In addition, the subjective evaluation of smell significantly improved (H = 11.935, p = 0.0026). At the 6- to 12-month follow-up, the majority of patients (5/7) reported extremely high levels of satisfaction with the outcomes, and the remaining two patients also felt generally positive about the therapy's success. Overall, our study showed that the use of intranasal inhalations as a method of delivering bioactive factors and the conditioned medium of M2 macrophages as a therapeutic agent are both safe, well tolerated and, according to preliminary data, clinically effective in the treatment of patients with long-term post-COVID-19 hyposmia.

[Ribonucleolytic activity of mycoplasmas].

Mycoplasmas are incapable of de novo synthesis of nucleotides and must therefore secrete nucleases in order to replenish the pool of nucleic acid precursors. The nucleolytic activity of mycoplasmas is an important factor in their pathogenicity. Bacterial ribonucleases (RNases) may produce a broad spectrum of biological effects, including antiviral and antitumor activity. Mycoplasma RNases are therefore of interest. In the present work, capacity of Acholeplasma laidlawii and Mycoplasma hominis for RNase synthesis and secretion was studied. During the stationary growth phase, these organisms were found to synthesize Mg(2+)-dependent RNases, with their highest activity detected outside the cells. Localization of A. laidlawii RNases was determined: almost 90% of the RNase activity was found to be associated with the membrane vesicles. Bioinformational analysis revealed homology between the nucleotide sequences of 14 Bacillus subtilis genes encoding the products with RNase activity and the genes of the mycoplasmas under study. Amino acid sequences of 4 A. laidlawii proteins with ribonuclease activity and the Bsn RNase was also established.

Periplasmic superoxide dismutase from Desulfovibrio desulfuricans 1388 is an iron protein.

It is shown that the genome of the sulfate-reducing bacterium Desulfovibrio desulfuricans 1388 contains a superoxide dismutase (SOD) gene (sod). The gene encodes an export signal peptide characteristic for periplasmic redox proteins. The amino acid sequence showed high homology with iron-containing SODs from other bacteria. Electrophoretically pure SOD was isolated from the periplasmic fraction of bacterial cells by FPLC chromatography. Like other Fe-SODs, D. desulfuricans 1388 superoxide dismutase is inhibited by H2O2 and azide, but not by cyanide.

Carbon monoxide inhibits superoxide dismutase and stimulates reactive oxygen species production by Desulfovibrio desulfuricans 1388.

The hypothesis that oxidative stress characterized by enhanced superoxide generation underlies the toxicity of some factors to living organisms has been investigated. It is shown that CO (5-6% in gas phase) changed some growth parameters (mu, t(d)) of the sulfate-reducing bacterium Desulfovibrio desulfuricans 1388. Enhanced O(2)(-) generation registered by EPR spectroscopy and adrenochrome method was observed when cells were incubated under CO. The SOD activity in cells from the exponential growth phase growing under CO was decreased 1.5-fold compared with the control cells growing under Ar. SOD activities in cells from the stationary growth phase growing with or without CO were comparable. The results support the concept that CO toxicity for sulfate-reducing bacteria is an oxidative stress that arises in cells oxidizing CO to CO(2).

FTIR-spectroscopic studies of the fine structure of nitrocellulose treated by Desulfovibrio desulfuricans.

Most studies have concluded that nitrocellulose (NC) with high degree of nitrogen content is resistant to biodegradation. Our results demonstrated that NC (>11%N) does undergo biotransformation in the presence of sulfate-reducing bacteria Desulfovibrio desulfuricans 1388. FTIR analyses indicated that the substitution of nitro groups for OH(-) groups took place. The spectrum of precipitate obtained after acetone extraction of NC resembled mainly the spectrum of native cellulose. Thus the synthetic unbiodegradable polymer was transformed to the natural compound accessible for microorganisms.

Antioxidative enzymes of sulfate-reducing bacterium desulfovibrio desulfuricans: superoxide dismutase and peroxidases.

Extracts of Desulfovibrio desulfuricans B-1388 cells grown under anaerobic conditions displayed superoxide dismutase activity. The maximal activity was found during the stationary growth phase. The enzyme was virtually completely located in the periplasm fraction. D. desulfuricans B-1388 lacked catalase activity but contained active NADH- and NADPH-peroxidases. The activity of NADH-peroxidase depended on the physiological state of the culture. On changing the growth conditions (the presence of 5% CO in the gaseous phase), the activity of superoxide dismutase decreased.

Anti-oxidant defense of the cell Desulfovibrio desulfuricans B-1388.

The extracts of Desulfovibrio desulfuricans B-1388 cells, grown in anaerobic condition, display the superoxide dismutase activity. The maximum value of level activity (1.02 E/min/mg) is observed in the stationary phase of growth. Essentially the whole enzyme is localized in periplasmic fraction. Cells Desulfovibrio desulfuricans B-1388 do not show the catalase activity but contain active NADH- and NADPH-peroxidases. The activity of involved peroxidases depends on the physiological condition of culture.

[Effect of carbon monoxide on the growth of sulfate-reducing bacteria and their oxidation of this substrate]. / Vliianie okisi ugleroda na rost sul'fatvosstanavlivaiushchikh bakterii i okislenie imi etogo substrata.

The effect of carbon monoxide on the growth of six strains of sulfatee-reducing bacteria have been studied as well as the ability of bacterial suspensions and extracts to oxidize CO. It was shown that sulfate-reducing bacteria possess a comparably high resistance to carbon monoxide. There are difference in the sensitivity of certain species and strains of sulphat-reducing bacteria to the content of CO in the gas phase. The cell suspensions and extracts are capable of oxidizing 100% CO in gaseous phase. The rate of carbon monoxide oxidation by extracts is much higher than by suspensions.

Degradation of maltose by proliferating cells of Desulfovibrio desulfuricans 2198.

Desulfovibrio desulfuricans 2198 can grow on maltose-based medium only in the presence of yeast extract. The results of kinetic measurements of maltose consumption by the cells show that there is no marked difference in Km and Vmax values for this bacterium versus other carbohydrate-utilizing microorganisms. The determination of some enzymes of sugar metabolism in D. desulfuricans 2198 suggests that maltose degradation occurs by the Embden--Meyerhof pathway. The cell extract also contains glucose 6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase. 2-Keto-3-deoxy-6-phosphogluconate aldolase, the key enzyme of the Entner--Doudoroff pathway, is not found in D. desulfuricans 2198. In the bacterium grown on [U-14C]maltose-containing medium, a portion of the labeled carbon is incorporated into biomass. As degradation products, labeled acetate and carbon dioxide are found.

[Nuclear DNAase of the yeast Candida tropicalis]. / DNKazy iader drozhzhei Candida tropicalis.

Using stepwise extraction of chromatin from Candida tropicalis by NaCl (0.1-1.0 M) the protein dissociated by 0.3 and 0.6 M NaCl (fractions 0.3 and 0.6) possessing the DNAase activity were obtained. These DNAases are activated by Mg2+ and cause preferential hydrolysis of heat-denaturated DNA. Fraction 0.3 DNAase has a maximum at neutral values of pH (around 7.0) and causes endonucleolytic hydrolysis of DNA. Fraction 0.6 DNAase causes exonucleolytic hydrolysis of DNA but a maximum at alkaline pH (8.0). The properties of isolated chromatin DNAases of Candida tropicalis differ from those of the known DNAases of the yeast Saccharomyces cerevisiae.

Biotechnological potential of sulfate-reducing bacteria for transformation of nitrocellulose.

The biotransformation of NC by Desulfovibrio sp. was studied. The mass of NC was decreased by 4.9-9.3%. The rate of NC transformation was between 46 and 73 mg NC per mg of bacterial protein in 10 days. Moreover, N content (%N) in the remaining NC was reduced by 2-12%. The inhibitory effect of NC was clearly expressed when the growth of D. desulfuricans 1388 in lactate/sulfate medium was initiated. The growth rate of bacteria was 1.5-fold greater when NC was not added (0.074 and 0.05 h(-1) respectively). The transformation of NC by D. desulfuricans was accompanied by the appearance of nitrate in the culture liquid, the amount of which reached the peak by the 8th day.

[Effect of pancreatic DNAse on the nuclear DNA topology of Candida tropicalis yeasts]. / Vliianie pankreaticheskoi DNKazy na topologiiu iadernoi DNK drozhzhei Candida tropicalis.

It has been shown that pancreatic DNAase added to the nutritious medium caused the change in the nuclear DNA topology of asporogenic Candida tropicalis yeast. DNA conformative changes are due to the unwinding of supertwisted molecules as a result of single-strand ruptures formation which induce DNA synthesis acceleration, cell growth and division.

Changes in the nitrocellulose molecule induced by sulfate-reducing bacteria Desulfovibrio desulfuricans 1,388. The enzymes participating in this process.

The appearance of unsubstituted glucopyranose residues in nitrocellulose (NC) induced by Desulfovibrio desulfuricans was established by (13)C-NMR spectroscopy. After contact with bacterial cells, the degree of substitution by nitro groups in NC decreased from 2.59 to 2.40. The bacteria possess intra- and extracellular nitroesterase activities, which are responsible for denitration of the polymer. The presence of NC in the growth medium influences the extracellular nitroesterase activity. It is shown that inhibition of enzymatic activity in the presence of NC is caused by appearance of nitrates in the culture medium. Nitrate and nitrite reductases of dissimilatory type reduce nitrates. The data suggest consideration of bacteria belonging to the Desulfovibrio genus as the initial agent in utilization of an unnatural polymer--nitrocellulose--in a microbial consortium.