Hydrogen Sulfide as a Toxic Product in the Small-Large Intestine Axis and its Role in IBD Development

The small-large intestine axis in hydrogen sulfide accumulation and testing of sulfate and lactate in the gut-gut axis of the intestinal environment has not been well described. Sulfate reducing bacteria (SRB) of the Desulfovibrio genus reduce sulfate to hydrogen sulfide and can be involved in ulcerative colitis development. The background of the research was to find correlations between hydrogen sulfide production under the effect of an electron acceptor (sulfate) and donor (lactate) at different concentrations and Desulfovibrio piger Vib-7 growth, as well as their dissimilatory sulfate reduction in the intestinal small-large intestinal environment. METHODS: Microbiological, biochemical, and biophysical methods, and statistical processing of the results (principal component and cross-correlation analyses) were used. RESULTS: D. piger Vib-7 showed increased intensity of bacterial growth and hydrogen sulfide production under the following concentrations of sulfate and lactate: 17.4 mM and 35.6 mM, respectively. The study showed in what kind of intestinal environment D. piger Vib-7 grows at the highest level and produces the highest amount of hydrogen sulfide. CONCLUSIONS: The optimum intestinal environment of D. piger Vib-7 can serve as a good indicator of the occurrence of inflammatory bowel diseases; meaning that these findings can be broadly used in medicine practice dealing with the monitoring and diagnosis of intestinal ailments

Активність каталази та супероксиддисмутази бактерій Desulfovibrio desulfuricans Ya-11 за впливу солей важких металів

The highest catalase activity (42.67×10–2 µM×min–1×mg–1 of protein) in the cells of Desulfovibrio desulfuricans Ya-11 has been observed under the prolonged Pb(NO3)2 influence. In the presence of other heavy metals’ salts it has been changed in dependence on their concentrations and growth duration. Based on our research data the row of heavy metals’ salts by its influence on D. desulfuricans Ya-11 catalase activity has been formed at first: Pb(NO3)2> CuCl2> CdCl2> ZnCl2. The highest superoxide dismutase activity (61.52×10–2 µM×min–1×mg–1 of protein) has been observed under the prolonged ZnCl2 influence. In the presence of other heavy metals’ salts this enzyme’s activity increased with increasing the salts’ concentrations. Based on our According to our results, the row of heavy metals’ salts influence on D. desulfuricans Ya-11 superoxide dismutase activity has been formed at first: ZnCl2 > Pb(NO3)2 > CuCl2 > CdCl2.Исследовано влияние CdCl2, Pb(NO3)2, CuCl2 и ZnCl2 на активность каталазы и супероксиддисмутазы клеток Desulfovibrio desulfuricans Ya-11. Самую высокую активность каталазы (42,67×10–2 мкмоль×мин.–1×мг–1 белка) определили при длительном действии Pb(NO3)2. При влиянии солей других металлов она изменяется в зависимости от их концентрации и длительности роста. На основании результатов исследований впервые определен ряд действия солей тяжелых металлов на активность каталазы бактерий D. desulfuricans Ya-11: Pb(NO3)2 > CuCl2 > CdCl2 > ZnCl2. Самая высокая активность супероксиддисмутазы (61,52×102 мкмоль×мин.–1×мг–1 белка) определена при длительном влиянии ZnCl2. Соли других тяжелых металлов вызывали увеличение активности исследуемого фермента с возрастанием их концентраций. Впервые определен ряд действия солей тяжелых металлов на активность каталазы бактерий D. desulfuricans Ya-11: ZnCl2 > Pb(NO3)2 > CuCl2 > CdCl2.Досліджено вплив CdCl2, Pb(NO3)2, CuCl2 та ZnCl2 на активність каталази та супероксиддисмутази клітин Desulfovibrio desulfuricans Ya-11. Найвищу активність каталази (42,67×10–2 мкмоль×хв–1×мг–1 білка) спостерігали за тривалої дії Pb(NO3)2. За дії інших солей металів вона змінюється залежно від їх концентрації та тривалості росту. На основі результатів досліджень уперше побудовано ряд дії солей важких металів на активність каталази бактерій D. desulfuricans Ya-11: Pb(NO3)2 > CuCl2 > CdCl2 > ZnCl2. Найвищу активність супероксиддисмутази (61,52×102 мкмоль×хв–1×мг–1 білка) спостерігали за тривалого впливу ZnCl2. Інші досліджувані солі спричиняли зростання активності даного ферменту зі збільшенням концентрації солі металу. Уперше побудовано ряд дії солей важких металів на активність каталази бактерій D. desulfuricans Ya-11: ZnCl2 > Pb(NO3)2 > CuCl2 > CdCl2.

NADH and NADPH peroxidases as antioxidant defense mechanisms in intestinal sulfate-reducing bacteria

Animal and human feces typically include intestinal sulfate-reducing bacteria (SRB). Hydrogen sulfide and acetate are the end products of their dissimilatory sulfate reduction and may create a synergistic effect. Here, we report NADH and NADPH peroxidase activities from intestinal SRB Desulfomicrobium orale and Desulfovibrio piger . We sought to compare enzymatic activities under the influence of various temperature and pH regimes, as well as to carry out kinetic analyses of enzymatic reaction rates, maximum amounts of the reaction product, reaction times, maximum rates of the enzyme reactions, and Michaelis constants in cell-free extracts of intestinal SRB, D. piger Vib-7, and D. orale Rod-9, collected from exponential and stationary growth phases. The optimal temperature (35 °C) and pH (7.0) for both enzyme’s activity were determined. The difference in trends of Michaelis constants ( K m ) during exponential and stationary phases are noticeable between D. piger Vib-7 and D. orale Rod-9; D. orale Rod-9 showed much higher K m (the exception is NADH peroxidase of D. piger Vib-7: 1.42 ± 0.11 mM) during the both monitored phases. Studies of the NADH and NADPH peroxidases—as putative antioxidant defense systems of intestinal SRB and detailed data on the kinetic properties of this enzyme, as expressed by the decomposition of hydrogen peroxide—could be important for clarifying evolutionary mechanisms of antioxidant defense systems, their etiological role in the process of dissimilatory sulfate reduction, and their possible role in the development of bowel diseases

Dose-dependent effect of electron acceptor and donor on dissimilatory sulfate reduction by bacteria Desulfovibrio Piger Vib-7 of human intestine

Growth of Desulfovibrio piger Vib-7 bacteria of human intestine under the influence of the electron acceptor and donor in different concentrations and the parameters of dissimilatory sulfate reduction have been studied. An increased intensity of the bacterial growth and production of hydrogen sulfide by the D. piger Vib-7 bacteria was studied under influence of high concentrations of sulfate and lactate (17.4 and 35.6 mM, respectively). The largest quantity of hydrogen sulfide (6.06 mM) under influence of 10.5 mM of SO42- was detected on the 72 hour of cultivation; while the bacteria D. piger Vib-7 used about 58% of sulfate ion. The largest quantity of acetate (21.1 mM) is detected on the 72 the hour of growth during cultivating the D. piger Vib-7 in the medium containing 53.4 mM of lactate. Based on the obtained experimental data surface models of sulfate reduction parameters by D. piger Vib-7 under the influence of electron acceptor and donor different concentrations were constructed. These surface models have provided an opportunity to confirm and establish optimum growing points by the studied bacteria, their sulfate consumption and sulfide production, the lactate consumption and acetate accumulation. The correlation coefficients (r) between parameters of the dissimilatory sulfate reduction by the D. piger Vib-7 were defined. Strong negative and positive correlations between these parameters have been observed

Dissimilatory sulfate reduction in the intestinal sulfate-reducing bacteria

The study of the intestinal sulfate-reducing bacteria, the process of dissimilatory sulfate reduction and accumulation of hydrogen sulfide, as well as their role in the inflammatory bowel diseases, including ulcerative colitis, in animals and human have increa­singly attracted the attention of scientists. New opportunities for studying inflammatory bowel disease and the assessment of the effectiveness of its treatment is an urgent problem of modern biology and medicine. In this review, brief characteristics of these bacteria and their mechanism of dissimilatory sulfate reduction were described based on modern literature data and own research. The characteristics of substrates for intestinal sulfate-reducing bacteria and the thermodynamic properties of their electron donors were also described. Special attention was paid to the mechanism and stages of sulfate dissimilation including role of enzymes involved in this process. Based on our results, general scheme of dissimilatory sulfate reduction sho­wing the activity of each enzyme of the process was demonstrated. The described physiological and biochemical parameters are important for a more detailed understanding of sulfate dissimilation in the human and animal bowel, as well as studying the mechanisms of action of the antimicrobial prophylactics and the therapy against specific components involved in the pathogenesis of the disease. It is also essential for understanding the mechanisms of bowel diseases and for evaluating the effectiveness of its therapy

Sulfate-reducing bacteria of the human intestine. I. Dissimilatory sulfate reduction

Modern literature data concerning sulfate-reducing bacteria of human intestine are summarized. The characterictics and mechanisms of dissimilatory sulfate reduction by these bacteria are described. Special attention is paid to the redox potentials of some electron donors and intermediate products of the dissimilatory sulfate reduction. The detailed characteristics of substrates for sulfate-reducing bacteria obtained from the intestine of man is presented. There are presented the most widespread concepts about the trophic interactions of studied bacteria with other microorganisms. The phylogenetic diversity of sulfate-reducing bacteria is described

Identification of sulfate-reducing bacteria strains of human large intestine

The sulfate-reducing bacteria have been isolated from human intestine. These bacteria are identified by their morphological, physiological and biochemical characteristics as the Desulfovibrio sp. and Desulfomicrobium sp. according to Bergey’s Manual of Determinative Bacteriology. Growth of the isolated strains of bacteria has been studied under various conditions including types of media, effect of oxygen, pH, and tempe­rature. Bacterial growth in the modified Kravtsov-Sorokin’s medium, and process of dissimilatory sulfate reduction by the selected strains of bacteria have been investiga­ted. All obtained bacterial cultures used sulfate and lactate intensively as well as produced hydrogen sulfide and acetate in the medium. The Desulfovibrio sp. strain Vib-7 produced the highest concentration (up to 3.23 mM) of hydrogen sulfide, while the bacteria used about 99% of sulfate ions presented in the medium. This strain also produced the highest concentration of acetate ions (up to 15.87 mM) on the fifth day of cultivation. Among the studied Desulfomicrobium sp. strains, the highest concentration of hydrogen sulfide was produced by the Desulfomicrobium sp. strain Rod-9, and the highest concentration of acetate ions was produced by the Desulfomicrobium sp. strain Rod-4

Dissimilatory sulfite reductase in cell-free extracts of intestinal sulfate-reducing bacteria

Dissimilatory sulfite reductase activity in different fractions of the sulfate-reducing bacteria Desulfovibrio piger Vib-7 and Desulfomicrobium sp. Rod-9 isolated from human intestine was studied. Sulfite reductase, an important enzyme in the process of sulfur metabolism in these bacteria, was solubilized from the membrane fraction. The highest activity of the enzyme in the cell-free extract of the bacterial strains was measured (0.032±0.0026 and 0.028±0.0022 U×mg-1 protein for D. piger Vib-7 and Desulfomicrobium sp. Rod-9, respectively) compared to other fractions. The optimal temperature (+30…35 °C) and pH 7.0 for sulfite reductase reaction in the extracts of both bacterial strains was determined. The spectral analysis of purified sulfite reductase from cell-free extracts was carried out. The absorption maxima were 284, 391, 412, 583, and 630 nm, as well as 287, 393, 545, and 581 nm for sulfite reductase of D. piger Vib-7 and Desulfomicrobium sp. Rod-9, respectively. Analysis of the kinetic properties of the bacterial sulfite reductase has been carried out. The sulfite reductase activity, initial (instantaneous) reaction rate (V0) and maximum rate of the sulfite reductase reaction (Vmax) were higher in the D. piger Vib-7 cells than in the Desulfomicrobium sp. Rod-9. However, Michaelis constants (Km) of the enzyme activity were similar for both bacterial strains. The studies of the sulfite reductase activity, the kinetic properties of this enzyme in the intestinal sulfate-reducing bacteria strains, and their production of hydrogen sulfide in detail can be useful for clarification of the etiological role of these bacteria in the development of inflammatory bowel diseases in humans and animals

The anoxygenic photosynthetic purple bacteria

Modern systematics of phototrophic purple bacteria is described. Their distribution and living conditions based on literature data and original research data are shown. The morphological characteristics, pigments composition and photosynthesis particularies are described. Participation of these bacteria in the natural sulfur cycle, the ways of their hydrogen sulphide usage are shown. The areas of practical application of purple phototrophic bacteria are pointed

Growth of various strains of sulfate-reducing bacteria of human large intestine

New strains of sulfate-reducing bacteria from human intestine are obtained. These bacteria are vibrio-like (strains SRB Vib-1, SRB Vib-2, SRB Vib-3) and short rod-like (strains SRB Rod-4 and SRB Rod-5) forms. The growth of these strains of bacteria, usage of sulfates by bacteria and their production of hydrogen sulfide are investigated. The strains of sulfate-reducing bacteria SRB Vib-1, SRB Vib-2, SRB Vib-3 more intensively accumulate biomass, compared with strains SRB Rod-4 і SRB Rod-5. The strains SRB Vib-1 and SRB Vib-2 grow the most intensively. Accumulation of bacterial biomass (3.8 g/l) is the highest on the third day of cultivation, after that the stationary growth phase began. The strain of bacteria SRB Vib-3 accumulates biomass 2.89 g/l on the third day of bacteria cultivation. Maximal biomass of SRB Rod-4 and SRB Rod-5 bacteria strains ranged from 2.59 to 3.25 g/l on the eighth day of cultivation. The obtained sulfate-reducing bacteria intensively use sulfate ions and produce hydrogen sulfide. The strains SRB Vib-1, SRB Vib-2, SRB Vib-3 produce from 2.99 mM to 3.12 mM of hydrogen sulfide. The rod-shaped strains of sulfate-reducing bacteria use sulfate ions and produce hydrogen sulfide less intensely in the presence of sulfates in the medium