scholarly journals Sulfidogenic and metal reducing activities of Desulfuromonas genus bacteria under the influence of copper chloride

2018 ◽  
Vol 26 (3) ◽  
pp. 218-226
Author(s):  
S. O. Hnatush ◽  
O. M. Moroz ◽  
G. V. Yavorska ◽  
B. M. Borsukevych

The selection of strains isolated from technogenically altered ecotopes and resistant to contamination, capable of metabolizing a wide range of pollutants is a task highly relevant for creation of new methods for environmental purification. Sulphur-reducing bacteria of the Desulfuromonas genus carry out dissimilatory reduction not only of S0 but also oxidized forms of metals. Intensity of anaerobic respiration of microorganisms in polluted environments is determined by level of their adaptation to stress factors, in particular, copper (II) compounds. The aim of this work was to investigate the influence of copper (II) chloride on H2S production by Desulfuromonas sp. strains isolated by us from Yavorivske Lake, to determine the efficiency of Cu2+ precipitation by hydrogen sulfide, to analyse the possibility of usage by bacteria of CuCl2 as an electron acceptor of anaerobic respiration and to study the influence of Cu2+ on usage by these microorganisms of ferric (III) citrate, potassium dichromate or manganese (IV) oxide as electron acceptors. Bacteria were grown under anaerobic conditions in Kravtsov-Sorokin medium. To study the influence of Cu2+ on production by bacteria of H2S, their cells were incubated with CuCl2 (0.5–4.0 mM), washed and cultivated in a medium with S0. To determine the level of Cu2+ binding by H2S, produced by bacteria, cells were grown in a medium with CuCl2 (0.5–4.0 mM) and S0. To investigate the ability of bacteria to use copper (II) ions as electron acceptors, they were cultivated in a medium with CuCl2 (1.74–10.41 mM). To study the influence of Cu2+ on usage by bacteria of metal compounds as electron acceptors, their cells were incubated with CuCl2 (0.5–4.0 mM), washed and cultivated in media with C6H5O7Fe, K2Cr2O7 or MnO2 (1.74–10.41 mM). Biomass was determined by the turbidimetric method. In the cultural liquid the content of H2S was determined quantitatively by the spectrophotometric method, qualitatively – presence of Cu2+. Content of CuS in the growth medium was determined by weight method. Desulfuromonas sp. bacteria was revealed to be resistant to 2.0–2.5 mM copper (II) ions. Under the influence of 3.0–4.0 mM CuCl2 in the incubation mixture, sulfidogenic activity of bacteria decreased more than twice. The efficiency of Cu2+ binding in form of CuS by H2S produced by bacteria reached 97.3–100.0% at presence in the medium with S0 of up to 1.5 mM CuCl2. Bacteria used CuCl2 (1.74–10.41 mM) as an electron acceptor in the process of anaerobic respiration. The addition of 2.5–3.0 mM CuCl2 to the incubation mixture caused inhibition of metal reducing activity of cells, growth of all strains in media with 1.74–10.41 mM ferric (III) citrate, potassium dichromate or manganese (IV) oxide as electron acceptors decreased by 2.6 times. Almost complete precipitation up to 1.5 mM copper (II) ions in form of CuS by H2S produced by bacteria and ability to reduce up to 10.41 mM CuCl2, C6H5O7Fe, K2Cr2O7 or MnO2 in the process of anaerobic respiration indicates a high adaptation of the bacteria strains investigated by us to stress factors, in particular, the influence of CuCl2. We have proved the possibility of using Desulfuromonas sp. in biotechnologies for purification of environments with complex contamination from copper (II) compounds.

2017 ◽  
Vol 28 (1-2) ◽  
pp. 84-95
Author(s):  
O. M. Moroz ◽  
S. O. Hnatush ◽  
Ch. I. Bohoslavets ◽  
T. M. Hrytsun’ ◽  
B. M. Borsukevych

Sulfate reducing bacteria, capable to reductive transformation of different nature pollutants, used in biotechnologies of purification of sewage, contaminated by carbon, sulfur, nitrogen and metal compounds. H2S formed by them sediment metals to form of insoluble sulfides. Number of metals can be used by these microorganisms as electron acceptors during anaerobic respiration. Because under the influence of metal compounds observed slowing of bacteria metabolism, selection isolated from technologically modified ecotops resistant to pollutions strains is important task to create a new biotechnologies of purification. That’s why the purpose of this work was to study the influence of potassium dichromate, present in medium, on reduction of sulfate and nitrate ions by sulfate reducing bacteria Desulfovibrio desulfuricans IMV K-6, Desulfovibrio sp. Yav-6 and Desulfovibrio sp. Yav-8, isolated from Yavorivske Lake, to estimate the efficiency of possible usage of these bacteria in technologies of complex purification of environment from dangerous pollutants. Bacteria were cultivated in modified Kravtsov-Sorokin medium without SO42- and FeCl2×4H2O for 10 days. To study the influence of K2Cr2O7 on usage by bacteria SO42- or NO3- cells were seeded to media with Na2SO4×10H2O or NaNO3 and K2Cr2O7 at concentrations of 1.74 mM for total content of electron acceptors in medium 3.47 mM (concentration of SO42- in medium of standard composition). Cells were also seeded to media with 3.47 mM Na2SO4×10H2O, NaNO3 or K2Cr2O7 to investigate their growth in media with SO42-, NO3- or Cr2O72- as sole electron acceptor (control). Biomass was determined by turbidymetric method, content of sulfate, nitrate, dichromate, chromium (III) ions, hydrogen sulfide or ammonia ions in cultural liquid – by spectrophotometric method. It was found that K2Cr2O7 inhibits growth (2.2 and 1.3 times) and level of reduction by bacteria sulfate or nitrate ions (4.2 and 3.0 times, respectively) at simultaneous addition into cultivation medium of 1.74 mM SO42- or NO3- and 1.74 mM Cr2O72-, compared with growth and level of reduction of sulfate or nitrate ions in medium only with SO42- or NO3- as sole electron acceptor. Revealed that during cultivation of bacteria in presence of equimolar amount of SO42- or NO3- and Cr2O72-, last used by bacteria faster, content of Cr3+ during whole period of bacteria cultivation exceeded content H2S or NH4+. K2Cr2O7 in medium has most negative influence on dissimilatory reduction by bacteria SO42- than NO3-, since level of nitrate ions reduction by cells in medium with NO3- and Cr2O72- was a half times higher than level of sulfate ions reduction by it in medium with SO42- and Cr2O72-. The ability of bacteria Desulfovibrio sp. to priority reduction of Cr2O72- and after their exhaustion − NO3- and SO42- in the processes of anaerobic respiration can be used in technologies of complex purification of environment from toxic compounds.


2002 ◽  
Vol 184 (15) ◽  
pp. 4187-4196 ◽  
Author(s):  
Michael J. Sellars ◽  
Stephen J. Hall ◽  
David J. Kelly

ABSTRACT The human gastrointestinal pathogen Campylobacter jejuni is a microaerophilic bacterium with a respiratory metabolism. The genome sequence of C. jejuni strain 11168 reveals the presence of genes that encode terminal reductases that are predicted to allow the use of a wide range of alternative electron acceptors to oxygen, including fumarate, nitrate, nitrite, and N- or S-oxides. All of these reductase activities were present in cells of strain 11168, and the molybdoenzyme encoded by Cj0264c was shown by mutagenesis to be responsible for both trimethylamine-N-oxide (TMAO) and dimethyl sulfoxide (DMSO) reduction. Nevertheless, growth of C. jejuni under strictly anaerobic conditions (with hydrogen or formate as electron donor) in the presence of any of the electron acceptors tested was insignificant. However, when fumarate, nitrate, nitrite, TMAO, or DMSO was added to microaerobic cultures in which the rate of oxygen transfer was severely restricted, clear increases in both the growth rate and final cell density compared to what was seen with the control were obtained, indicative of electron acceptor-dependent energy conservation. The C. jejuni genome encodes a single class I-type ribonucleotide reductase (RNR) which requires oxygen to generate a tyrosyl radical for catalysis. Electron microscopy of cells that had been incubated under strictly anaerobic conditions with an electron acceptor showed filamentation due to an inhibition of cell division similar to that induced by the RNR inhibitor hydroxyurea. An oxygen requirement for DNA synthesis can thus explain the lack of anaerobic growth of C. jejuni. The results indicate that strict anaerobiosis is a stress condition for C. jejuni but that alternative respiratory pathways can contribute significantly to energy conservation under oxygen-limited conditions, as might be found in vivo.


2016 ◽  
Vol 24 (1) ◽  
pp. 87-95 ◽  
Author(s):  
O. M. Moroz ◽  
S. O. Hnatush ◽  
C. I. Bohoslavets ◽  
G. V. Yavorska ◽  
N. V. Truchym

The toxicity of metal ions to microorganisms, in particular at high concentrations, is one of the main impediments to their usage in remediation technologies. The purpose of this work is to analyze the possibility of usage by bacteria of the Desulfuromonas genus, isolated by us from Yavorivske Lake, of ferrum (ІІІ) and manganese (IV) ions at concentrations in the medium of 1,74–10,41 mM as electron acceptors of anaerobic respiration to assesss resistance of sulphur reducing bacteria strains to heavy metal compounds. Cells of Desulfuromonas acetoxidans ІМV V-7384, Desulfuromonas sp. Yavor-5 and Desulfuromonas sp. Yavor-7 were cultivated for 10 days at 30 °C under anaerobic conditions in Kravtsov-Sorokin’s medium without sulphate ions, sulphur, with cysteine as the sulphur source (0.2 g/l) and sodium lactate or citrate as the electron donor (17.86 g/l), in which were added sterile 1 M solutions of C6H5O7Fe and C4H4O4 (control) and also weights of MnO2 to their terminal concentrations 1.74, 3.47, 5.21, 6.94, 10.41 mM. Biomass was determined by the turbidimetric method. In the culture liquid the presence of Fe3+ and Mn4+ were qualitatively determined, and the content of Fe2+ in reaction with о-phenanthroline was determined quantitatively. It was established that sulphur reducing bacteria used with different intensity ferrum (ІІІ) and manganese (IV) ions as electron acceptors during the process of anaerobic respiration at concentrations of 1.74–10.41 mM C6H5O7Fe and MnO2 in the medium, which demonstrated the important role of the investigated microorganisms in reductive detoxication of natural and technogenic media from oxidized forms of transitional heavy metals. An insignificant difference in biomass accumulation during usage of 5.21–10.41 mM ferrum (ІІІ) ions and fumarate is caused by toxicity of the metal ions to cells since the high redox potential of the Fe(III)/Fe(ІІ) pair with increase in concentrations of electron acceptors in the medium did not lead to increase in the biomass accumulation level. The greatest biomass of the bacteria accumulated on the 8–10th days in the medium with the lowest concentration of C6H5O7Fe – 1.74 mM (up to 2.77 g/l), and the lowest biomass – with highest concentration – 10.41 mM (up to 2.41 g/l). After 10 days of cultivation the bacteria of all strains had fully used the ferrum (ІІІ) ions present in the medium. A biomass yield almost twice as low was revealed after manganese (IV) oxide was used by bacteria compared with its use of ferrum (ІІІ) citrate and fumarate at all studied concentrations of electron acceptors in the medium. The highest biomass of bacteria accumulated in the medium with the lowest MnO2 content – 1.74 mM (up to 1.35 g/l), and the lowest biomass in the medium with the highest content – 10.41 mM (up to 1.15 g/l). After 10 days of cultivation bacteria of all strains had not fully restored the manganese (IV) ions present in the medium. The greatest biomass compared with other strains after growth in medium with different C6H5O7Fe and MnO2 contents was accumulated by the strain Desulfuromonas sp. Yavor-7. Since sulphur reducing bacteria strains proved to be resistant to Fe3+ and Mn4+ high concentrations (up to10.41 mM) they can be successfully used in technologies of environmenal remediation from sulphur and heavy metal compounds. 


2006 ◽  
Vol 189 (3) ◽  
pp. 1036-1043 ◽  
Author(s):  
Jason R. Dale ◽  
Roy Wade ◽  
Thomas J. DiChristina

ABSTRACT Shewanella putrefaciens strain 200 respires a wide range of compounds as terminal electron acceptor. The respiratory versatility of Shewanella is attributed in part to a set of c-type cytochromes with widely varying midpoint redox potentials (E′0). A point mutant of S. putrefaciens, originally designated Urr14 and here renamed CCMB1, was found to grow at wild-type rates on electron acceptors with high E′0 [O2, NO3 −, Fe(III) citrate, MnO2, and Mn(III) pyrophosphate] yet was severely impaired for growth on electron acceptors with low E′0 [NO2 −, U(VI), dimethyl sulfoxide, TMAO (trimethylamine N-oxide), fumarate, γ-FeOOH, SO3 2−, and S2O3 2−]. Genetic complementation and nucleotide sequence analyses indicated that the CCMB1 respiratory mutant phenotype was due to mutation of a conserved histidine residue (H108Y) in a protein that displayed high homology to Escherichia coli CcmB, the permease subunit of an ABC transporter involved in cytochrome c maturation. Although CCMB1 retained the ability to grow on electron acceptors with high E′0, the cytochrome content of CCMB1 was <10% of that of the wild-type strain. Periplasmic extracts of CCMB1 contained slightly greater concentrations of the thiol functional group (-SH) than did the wild-type strain, an indication that the Eh of the CCMB1 periplasm was abnormally low. A ccmB deletion mutant was unable to respire anaerobically on any electron acceptor, yet retained aerobic respiratory capability. These results suggest that the mutation of a conserved histidine residue (H108) in CCMB1 alters the redox homeostasis of the periplasm during anaerobic growth on electron acceptors with low (but not high) E′0. This is the first report of the effects of Ccm deficiencies on bacterial respiration of electron acceptors whose E′0 nearly span the entire redox continuum.


2020 ◽  
Vol 16 (4) ◽  
pp. 537-542
Author(s):  
Zhigacheva Irina ◽  
Volodkin Aleksandr ◽  
Rasulov Maksud

Background: One of the main sources of ROS in stress conditions is the mitochondria. Excessive generation of ROS leads to oxidation of thiol groups of proteins, peroxidation of membrane lipids and swelling of the mitochondria. In this regard, there is a need to search for preparationsadaptogens that increase the body's resistance to stress factors. Perhaps, antioxidants can serve as such adaptogens. This work aims at studying the effect of antioxidant; the potassium anphen in a wide range of concentrations on the functional state of 6 day etiolated pea seedlings mitochondria (Pisum sativum L). Methods: The functional state of mitochondria was studied per rates of mitochondria respiration, by the level of lipid peroxidation and study of fatty acid composition of mitochondrial membranes by chromatography technique. Results: Potassium anphen in concentrations of 10-5 - 10-8 M and 10-13-10-16 prevented the activation of LPO in the mitochondrial membranes of pea seedlings, increased the oxidation rates of NAD-dependent substrates and succinate in the respiratory chain of mitochondria that probably pointed to the anti-stress properties of the drug. Indeed, the treatment of pea seeds with the preparation in concentrations of 10-13 M prevented the inhibition of growth of seedlings in conditions of water deficiency. Conclusion: It is assumed that the dose dependence of the biological effects of potassium anphen and the manifestation of these effects in ultra-low concentrations are due to its ability in water solutions to form a hydrate containing molecular ensembles (structures).


2016 ◽  
Vol 27 (1) ◽  
pp. 15-21 ◽  
Author(s):  
M Kumaresan

Purpose – The purpose of this paper is to extract the eco-friendly natural dye obtained from the flower of Spathodea campanulata and apply on silk fabric using combination of mordants. The fastness properties of the flower of Spathodea campanulata dyed silk fabric have been studied using different combination (1:3, 1:1 and 3:1) of various mordants, such as myrobolan: nickel sulphate, myrobolan: aluminium sulphate, myrobolan: potassium dichromate, myrobolan: ferrous sulphate and myrobolan: stannous chloride. The wash, rub, light and perspiration fastness of the dyed samples have been evaluated. Design/methodology/approach – For dyeing there are three methods are used. They are Pre mordanting, Simultaneous mordanting and Post mordanting methods. Dyed silk materials are tested by using wash fastness, rub fastness, light and perspiration fastness methods. Findings – It is found that Spathodea campanulata dye can be successfully used for the dyeing of silk to obtain a wide range colours by using various combinations of mordants. With regards to colour fastness, test samples exhibit excellent fastness to washing, rubbing, except for pre-mordanting using myrobolan: potassium dichromate combination; and good to excellent fastness to perspiration in both acidic and alkaline media. Originality/value – Availability of literature related to this work is not available. The study of combination of mordants of this natural dye on silk is a new research work and the large scale preparation is definitely very useful to the society.


2005 ◽  
Vol 71 (7) ◽  
pp. 3741-3746 ◽  
Author(s):  
Alison M. Cupples ◽  
Robert A. Sanford ◽  
Gerald K. Sims

ABSTRACT Desulfitobacterium chlororespirans has been shown to grow by coupling the oxidation of lactate to the metabolic reductive dehalogenation of ortho chlorines on polysubstituted phenols. Here, we examine the ability of D. chlororespirans to debrominate and deiodinate the polysubstituted herbicides bromoxynil (3,5-dibromo-4-hydroxybenzonitrile), ioxynil (3,5-diiodo-4-hydroxybenzonitrile), and the bromoxynil metabolite 3,5-dibromo-4-hydroxybenzoate (DBHB). Stoichiometric debromination of bromoxynil to 4-cyanophenol and DBHB to 4-hydroxybenzoate occurred. Further, bromoxynil (35 to 75 μM) and DBHB (250 to 260 μM) were used as electron acceptors for growth. Doubling times for growth (means ± standard deviations for triplicate cultures) on bromoxynil (18.4 ± 5.2 h) and DBHB (11.9 ± 1.4 h), determined by rate of [14C]lactate uptake into biomass, were similar to those previously reported for this microorganism during growth on pyruvate (15.4 h). In contrast, ioxynil was not deiodinated when added alone or when added with bromoxynil; however, ioxynil dehalogenation, with stoichiometric conversion to 4-cyanophenol, was observed when the culture was amended with 3-chloro-4-hydroxybenzoate (a previously reported electron acceptor). To our knowledge, this is the first direct report of deiodination by a bacterium in the Desulfitobacterium genus and the first report of an anaerobic pure culture with the ability to transform bromoxynil or ioxynil. This research provides valuable insights into the substrate range of D. chlororespirans.


2007 ◽  
Vol 74 (1) ◽  
pp. 251-258 ◽  
Author(s):  
Kazem Kashefi ◽  
Evgenya S. Shelobolina ◽  
W. Crawford Elliott ◽  
Derek R. Lovley

ABSTRACT Recent studies have suggested that the structural Fe(III) within phyllosilicate minerals, including smectite and illite, is an important electron acceptor for Fe(III)-reducing microorganisms in sedimentary environments at moderate temperatures. The reduction of structural Fe(III) by thermophiles, however, has not previously been described. A wide range of thermophilic and hyperthermophilic Archaea and Bacteria from marine and freshwater environments that are known to reduce poorly crystalline Fe(III) oxides were tested for their ability to reduce structural (octahedrally coordinated) Fe(III) in smectite (SWa-1) as the sole electron acceptor. Two out of the 10 organisms tested, Geoglobus ahangari and Geothermobacterium ferrireducens, were not able to conserve energy to support growth by reduction of Fe(III) in SWa-1 despite the fact that both organisms were originally isolated with solid-phase Fe(III) as the electron acceptor. The other organisms tested were able to grow on SWa-1 and reduced 6.3 to 15.1% of the Fe(III). This is 20 to 50% less than the reported amounts of Fe(III) reduced in the same smectite (SWa-1) by mesophilic Fe(III) reducers. Two organisms, Geothermobacter ehrlichii and archaeal strain 140, produced copious amounts of an exopolysaccharide material, which may have played an active role in the dissolution of the structural iron in SWa-1 smectite. The reduction of structural Fe(III) in SWa-1 by archaeal strain 140 was studied in detail. Microbial Fe(III) reduction was accompanied by an increase in interlayer and octahedral charges and some incorporation of potassium and magnesium into the smectite structure. However, these changes in the major element chemistry of SWa-1 smectite did not result in the formation of an illite-like structure, as reported for a mesophilic Fe(III) reducer. These results suggest that thermophilic Fe(III)-reducing organisms differ in their ability to reduce and solubilize structural Fe(III) in SWa-1 smectite and that SWa-1 is not easily transformed to illite by these organisms.


2013 ◽  
Vol 61 (2) ◽  
pp. 161-172 ◽  
Author(s):  
M. Pál ◽  
O. Gondor ◽  
T. Janda

Low temperature is one of the most important limiting factors for plant growth throughout the world. Exposure to low temperature may cause various phenotypic and physiological symptoms, and may result in oxidative stress, leading to loss of membrane integrity and to the impairment of photosynthesis and general metabolic processes. Salicylic acid (SA), a phenolic compound produced by a wide range of plant species, may participate in many physiological and metabolic reactions in plants. It has been shown that exogenous SA may provide protection against low temperature injury in various plant species, while various stress factors may also modify the synthesis and metabolism of SA. In the present review, recent results on the effects of SA and related compounds in processes leading to acclimation to low temperatures will be discussed.


1996 ◽  
Vol 166 (3) ◽  
pp. 204-210 ◽  
Author(s):  
Thomas J. Lie ◽  
Thomas Pitta ◽  
E. R. Leadbetter ◽  
Walter Godchaux III. ◽  
Jared R. Leadbetter

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