Identification of a Bacterial Consortium with Biotechnological Potential for Arsenic Bioremediation

2013 ◽  
Vol 825 ◽  
pp. 540-543
Author(s):  
Mariana Moreira ◽  
Silvana de Queiroz Silva ◽  
Mônica Cristina Teixeira

The objective of this work was to identify one bacterial consortium adapted to the cultivation in the presence of trivalent arsenic (AsIII). Samples were cultured in flasks containing modified Postgate C liquid medium (selective for sulfate-reducing bacteria, SRB). Six different As concentrations were used: 0.5, 1.0, 2.0, 4.0, 8.0 and 16 mg l-1. The growth of sulfate reducing microorganisms was indirectly observed by the formation of an iron sulfide black precipitate and also by the Eh measures.100 ml aliquots of cultured media were centrifuged and stored at-20°C for DNA extraction by phenol/chloroform method. Universal primers 968F-GC 1392R (Bacteria domain) were used for 16S ribosomal DNA amplification. Microbial diversity was evaluated by denaturing gradient gel electrophoresis (DGGE). After DGGE analysis 7 different bands were selected, cut, sequenced and analyzed using the Ribosomal Database Project Release. Consortium microorganisms identified were: Pantoea agglomerans, Enterobacter sp, Citrobacter sp, Cupriavidusmetallidurans, Ralstonia sp, Burkholderia cepacia and Bacillus sp. Thus the microbial consortium here identified is a good candidate for bioremediation of arsenic contaminated areas and effluents.

2003 ◽  
Vol 69 (3) ◽  
pp. 1847-1853 ◽  
Author(s):  
Y. Meriah Arias ◽  
Bradley M. Tebo

ABSTRACT In time course experiments, bacterial community compositions were compared between a sulfidogenic and two nonsulfidogenic Cr(VI)-reducing consortia enriched from metal-contaminated sediments. The consortia were subjected to 0 and 0.85 mM or 1.35 mM Cr(VI), and Cr(VI) reduction, growth, and denaturing gradient gel electrophoresis profiles of PCR products of small-subunit (16S) ribosomal genes were compared. Results showed that although Cr(VI) was completely reduced by the three consortia, Cr(VI) inhibited cell growth, with sulfate-reducing bacteria being particularly sensitive to Cr(VI) toxicity relative to other bacteria in the consortia.


2005 ◽  
Vol 71 (5) ◽  
pp. 2325-2330 ◽  
Author(s):  
Shabir A. Dar ◽  
J. Gijs Kuenen ◽  
Gerard Muyzer

ABSTRACT Here, we describe a three-step nested-PCR-denaturing gradient gel electrophoresis (DGGE) strategy to detect sulfate-reducing bacteria (SRB) in complex microbial communities from industrial bioreactors. In the first step, the nearly complete 16S rRNA gene was amplified using bacterial primers. Subsequently, this product was used as a template in a second PCR with group-specific SRB primers. A third round of amplification was conducted to obtain fragments suitable for DGGE. The largest number of bands was observed in DGGE patterns of products obtained with primers specific for the Desulfovibrio-Desulfomicrobium group, indicating a large diversity of these SRBs. In addition, members of other phylogenetic SRB groups, i.e., Desulfotomaculum, Desulfobulbus, and Desulfococcus-Desulfonema-Desulfosarcina, were detected. Bands corresponding to Desulfobacterium and Desulfobacter were not detected in the bioreactor samples. Comparative sequence analysis of excised DGGE bands revealed the identity of the community members. The developed three-step PCR-DGGE strategy is a welcome tool for studying the diversity of sulfate-reducing bacteria.


2014 ◽  
Vol 2014 ◽  
pp. 1-21 ◽  
Author(s):  
Fayyaz Ali Shah ◽  
Qaisar Mahmood ◽  
Mohammad Maroof Shah ◽  
Arshid Pervez ◽  
Saeed Ahmad Asad

Anaerobic digestion is the method of wastes treatment aimed at a reduction of their hazardous effects on the biosphere. The mutualistic behavior of various anaerobic microorganisms results in the decomposition of complex organic substances into simple, chemically stabilized compounds, mainly methane andCO2. The conversions of complex organic compounds toCH4andCO2are possible due to the cooperation of four different groups of microorganisms, that is, fermentative, syntrophic, acetogenic, and methanogenic bacteria. Microbes adopt various pathways to evade from the unfavorable conditions in the anaerobic digester like competition between sulfate reducing bacteria (SRB) and methane forming bacteria for the same substrate.Methanosarcinaare able to use both acetoclastic and hydrogenotrophic pathways for methane production. This review highlights the cellulosic microorganisms, structure of cellulose, inoculum to substrate ratio, and source of inoculum and its effect on methanogenesis. The molecular techniques such as DGGE (denaturing gradient gel electrophoresis) utilized for dynamic changes in microbial communities and FISH (fluorescentin situhybridization) that deal with taxonomy and interaction and distribution of tropic groups used are also discussed.


2006 ◽  
Vol 73 (2) ◽  
pp. 594-604 ◽  
Author(s):  
Shabir A. Dar ◽  
Li Yao ◽  
Udo van Dongen ◽  
J. Gijs Kuenen ◽  
Gerard Muyzer

ABSTRACTHere we describe the diversity and activity of sulfate-reducing bacteria (SRB) in sulfidogenic bioreactors by using the simultaneous analysis of PCR products obtained from DNA and RNA of the 16S rRNA and dissimilatory sulfite reductase (dsrAB) genes. We subsequently analyzed the amplified gene fragments by using denaturing gradient gel electrophoresis (DGGE). We observed fewer bands in the RNA-based DGGE profiles than in the DNA-based profiles, indicating marked differences in the populations present and in those that were metabolically active at the time of sampling. Comparative sequence analyses of the bands obtained from rRNA anddsrBDGGE profiles were congruent, revealing the same SRB populations. Bioreactors that received either ethanol or isopropanol as an energy source showed the presence of SRB affiliated withDesulfobulbus rhabdoformisand/orDesulfovibrio sulfodismutans, as well as SRB related to the acetate-oxidizingDesulfobacca acetoxidans. The reactor that received wastewater containing a diverse mixture of organic compounds showed the presence of nutritionally versatile SRB affiliated withDesulfosarcina variabilisand another acetate-oxidizing SRB, affiliated withDesulfoarculus baarsii. In addition to DGGE analysis, we performed whole-cell hybridization with fluorescently labeled oligonucleotide probes to estimate the relative abundances of the dominant sulfate-reducing bacterial populations.Desulfobacca acetoxidans-like populations were most dominant (50 to 60%) relative to the total SRB communities, followed byDesulfovibrio-like populations (30 to 40%), andDesulfobulbus-like populations (15 to 20%). This study is the first to identify metabolically active SRB in sulfidogenic bioreactors by using the functional genedsrABas a molecular marker. The same approach can also be used to infer the ecological role of coexisting SRB in other habitats.


1998 ◽  
Vol 64 (8) ◽  
pp. 2943-2951 ◽  
Author(s):  
Andreas Teske ◽  
Niels B. Ramsing ◽  
Kirsten Habicht ◽  
Manabu Fukui ◽  
Jan Küver ◽  
...  

ABSTRACT The sulfate-reducing bacteria within the surface layer of the hypersaline cyanobacterial mat of Solar Lake (Sinai, Egypt) were investigated with combined microbiological, molecular, and biogeochemical approaches. The diurnally oxic surface layer contained between 106 and 107 cultivable sulfate-reducing bacteria ml−1 and showed sulfate reduction rates between 1,000 and 2,200 nmol ml−1 day−1, both in the same range as and sometimes higher than those in anaerobic deeper mat layers. In the oxic surface layer and in the mat layers below, filamentous sulfate-reducing Desulfonema bacteria were found in variable densities of 104 to 106cells ml−1. A Desulfonema-related, diurnally migrating bacterium was detected with PCR and denaturing gradient gel electrophoresis within and below the oxic surface layer. Facultative aerobic respiration, filamentous morphology, motility, diurnal migration, and aggregate formation were the most conspicuous adaptations of Solar Lake sulfate-reducing bacteria to the mat matrix and to diurnal oxygen stress. A comparison of sulfate reduction rates within the mat and previously published photosynthesis rates showed that CO2 from sulfate reduction in the upper 5 mm accounted for 7 to 8% of the total photosynthetic CO2 demand of the mat.


2011 ◽  
Vol 2011 ◽  
pp. 1-22 ◽  
Author(s):  
Lilia Montoya ◽  
Irma Lozada-Chávez ◽  
Ricardo Amils ◽  
Nuria Rodriguez ◽  
Irma Marín

Our goal was to examine the composition of methanogenic archaea (MA) and sulfate-reducing (SRP) and sulfur-oxidizing (SOP) prokaryotes in the extreme athalassohaline and particularly sulfate-rich sediment of Tirez Lagoon (Spain). Thus, adenosine-5′-phosphosulfate (APS) reductase α (aprA) and methyl coenzyme M reductase α (mcrA) gene markers were amplified given that both enzymes are specific for SRP, SOP, and MA, respectively. Anaerobic populations sampled at different depths in flooded and dry seasons from the anoxic sediment were compared qualitatively via denaturing gradient gel electrophoresis (DGGE) fingerprint analysis. Phylogenetic analyses allowed the detection of SRP belonging to Desulfobacteraceae, Desulfohalobiaceae, and Peptococcaceae in ∂-proteobacteria and Firmicutes and SOP belonging to Chromatiales/Thiotrichales clade and Ectothiorhodospiraceae in γ-proteobacteria as well as MA belonging to methylotrophic species in Methanosarcinaceae and one hydrogenotrophic species in Methanomicrobiaceae. We also estimated amino acid composition, GC content, and preferential codon usage for the AprA and McrA sequences from halophiles, nonhalophiles, and Tirez phylotypes. Even though our results cannot be currently conclusive regarding the halotolerant strategies carried out by Tirez phylotypes, we discuss the possibility of a plausible “salt-in” signal in SRP and SOP as well as of a speculative complementary haloadaptation between salt-in and salt-out strategies in MA.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Qiufen Li ◽  
Yan Zhang ◽  
David Juck ◽  
Nathalie Fortin ◽  
Charles W. Greer

The impact of intensive land-based fish culture in Qingdao, China, on the bacterial communities in surrounding marine environment was analyzed. Culture-based studies showed that the highest counts of heterotrophic, ammonium-oxidizing, nitrifying, and nitrate-reducing bacteria were found in fish ponds and the effluent channel, with lower counts in the adjacent marine area and the lowest counts in the samples taken from 500 m off the effluent channel. Denaturing gradient gel electrophoresis (DGGE) analysis was used to assess total bacterial diversity. Fewer bands were observed from the samples taken from near the effluent channel compared with more distant sediment samples, suggesting that excess nutrients from the aquaculture facility may be reducing the diversity of bacterial communities in nearby sediments. Phylogenetic analysis of the sequenced DGGE bands indicated that the bacteria community of fish-culture-associated environments was mainly composed of Flavobacteriaceae, gamma- and deltaproteobacteria, including generaGelidibacter, Psychroserpen, Lacinutrix,andCroceimarina.


Geophysics ◽  
1991 ◽  
Vol 56 (6) ◽  
pp. 748-757 ◽  
Author(s):  
M. B. Goldhaber ◽  
R. L. Reynolds

This paper focuses on the association between concentrations of iron disulfide [Formula: see text] minerals in the shallow subsurface and underlying hydrocarbon accumulations. Such [Formula: see text] concentrations are the result of migration of either [Formula: see text] or organic constituents from the underlying hydrocarbons. The [Formula: see text] from reservoirs is produced inorganically from sulfate in the reservoir rocks at high temperature (>90°C) and migrates to shallower beds to react inorganically with iron to form [Formula: see text]. Organic constituents from reservoirs, in contrast, provide nourishment for sulfate reducing bacteria in shallow relatively cool (<90°C) beds. Sandstone in the Ray Point uranium district in Live Oak County, Texas contains abundant [Formula: see text] which formed both from deep‐seated [Formula: see text] and from [Formula: see text] produced in the shallow subsurface by bacteria that utilized organic materials from depth. Deep petroleum reservoirs were physically connected to near‐surface (<100 m) beds containing epigenetic [Formula: see text] by the Oakville fault. Epigenetic iron sulfide formation occurred in at least four episodes over at least five million years. Evidence from the Ray Point district and elsewhere in Texas illustrates that sulfidization reactions have destroyed magnetic iron‐titanium oxide minerals in the vicinity of major growth faults, resulting in a systematic decrease in magnetic susceptibility and magnitude of remanent magnetization in the vicinity of such faults. Growth faults which tap hydrocarbon deposits may be detectable using aeromagnetic methods.


2011 ◽  
Vol 23 (6) ◽  
pp. 549-555 ◽  
Author(s):  
Patricio A. Muñoz ◽  
Patricio A. Flores ◽  
Freddy A. Boehmwald ◽  
Jenny M. Blamey

AbstractDeception Island, an active stratovolcano located in the South Shetland Islands, Antarctica, provides excellent conditions for the thermophilic bacteria growth because of high ground temperatures in specific areas, such as Fumarole Bay where the temperatures are above the mesophilic range. Denaturing Gradient Gel Electrophoresis (DGGE) was used with the 16S ribosomal gene to analyse cultures of thermophilic bacteria from a soil sample taken from Fumarole Bay. Nine bands were sequenced and analysed from DGGE and they indicated the presence of bacteria from the generaGeobacillus,Bacillus,Brevibacillus,Thermusand uncultured sulphate reducing bacteria. Some of which have been reported in other Antarctic geothermal sites.Geobacillus,BacillusandBrevibacillusgenera were successfully cultivated in an enriched medium. A pure culture of one thermophilicGeobacillusbacterium was obtained closely related toGeobacillus jurassicus.


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