Robustness of an aerobic metabolically vinyl chloride degrading bacterial enrichment culture

2011 ◽  
Vol 64 (9) ◽  
pp. 1796-1803 ◽  
Author(s):  
He-Ping Zhao ◽  
Kathrin R. Schmidt ◽  
Svenja Lohner ◽  
Andreas Tiehm
Keyword(s):  
Vinyl Chloride ◽  
Natural Attenuation ◽  
Enrichment Culture ◽  
Contaminated Sites ◽  
Contaminated Groundwater ◽  
Chlorinated Ethene ◽  
Equimolar Concentration ◽  
Bacterial Enrichment ◽  
Ph Tolerance

Degradation of the lower chlorinated ethenes is crucial to the application of natural attenuation or in situ bioremediation on chlorinated ethene contaminated sites. Recently, within mixtures of several chloroethenes as they can occur in contaminated groundwater inhibiting effects on aerobic chloroethene degradation have been shown. The current study demonstrated that metabolic vinyl chloride (VC) degradation by an enrichment culture originating from groundwater was not affected by an equimolar concentration (50 μM) of cis-1,2-dichloroethene (cDCE). Only cDCE concentrations at a ratio of 2.4:1 (initial cDCE to VC concentration) caused minor inhibition of VC degradation. Furthermore, the degradation of VC was not affected by the presence of trans-1,2-dichloroethene (tDCE), 1,1-dichloroethene (1,1-DCE), trichloroethene (TCE), and tetrachloroethene (PCE) in equimolar concentrations (50 μM). Only cDCE and tDCE were cometabolically degraded in small amounts. The VC-degrading culture demonstrated a broad pH tolerance from 5 to 9 with an optimum between 6 and 7. Results also showed that the culture could degrade VC concentrations up to 1,800 μM (110 mg/L).

scholarly journals Potential forMethanosarcinato contribute to uranium reduction during acetate-promoted groundwater bioremediation

2017 ◽  
Author(s):  
Dawn E Holmes ◽  
Roberto Orelana ◽  
Ludovic Giloteaux ◽  
Li-Ying Wang ◽  
Pravin Shrestha ◽  
...  
Keyword(s):  
Field Experiment ◽  
Electron Donor ◽  
Enrichment Culture ◽  
Cell Suspensions ◽  
Contaminated Groundwater ◽  
Subunit A ◽  
Sedimentary Environments

AbstractPrevious studies ofin situbioremediation of uranium-contaminated groundwater with acetate injections have focused on the role ofGeobacterspecies in U(VI) reduction because of a lack of other abundant known U(VI)-reducing microorganisms. Monitoring the levels of methyl CoM reductase subunit A (mcrA) transcripts during an acetate-injection field experiment demonstrated that acetoclastic methanogens from the genusMethanosarcinawere enriched after 40 days of acetate amendment. The increased abundance ofMethanosarcinacorresponded with an accumulation of methane in the groundwater. An enrichment culture dominated by aMethanosarcinaspecies with the sameMethanosarcina mcrAsequence that predominated in the field experiment could effectively convert acetate to methane. In order to determine whetherMethanosarcinaspecies could be participating in U(VI) reduction in the subsurface, cell suspensions ofM. barkeriwere incubated in the presence of U(VI) with acetate provided as the electron donor. U(VI) was reduced by metabolically activeM. barkericells, however, no U(VI) reduction was observed in inactive controls. These results demonstrate thatMethanosarcinaspecies could play an important role in the long-term bioremediation of uranium-contaminated aquifers after depletion of Fe(III) oxides limits the growth ofGeobacterspecies. The results also suggest thatMethanosarcinahave the potential to influence uranium geochemistry in a diversity of anaerobic sedimentary environments.

Substrate interactions during aerobic biodegradation of methane, ethene, vinyl chloride and 1,2-dichloroethenes

2001 ◽  
Vol 43 (5) ◽  
pp. 333-340 ◽  
Author(s):  
D. L. Freedman ◽  
A. S. Danko ◽  
M. F. Verce
Keyword(s):  
Vinyl Chloride ◽  
Natural Attenuation ◽  
Enrichment Culture ◽  
Active Role ◽  
Aerobic Biodegradation ◽  
Aerobic Conditions ◽  
Lag Period ◽  
Anaerobic Zone ◽  
Set Up ◽  
Cis And Trans

Intrinsic biodegradation of trichloroethene and 1,1,1-trichloroethane in groundwater at a Superfund site in California has been observed. An anaerobic zone exists in the area closest to the source location, yielding the expected complement of reductive dechlorination daughter products, including cis-1,2-dichloroethene (cis-DCE) and vinyl chloride (VC). Significant levels of methane and ethene were also generated in the anaerobic zone. The groundwater returns to aerobic conditions downgradient of the source, with methane, ethene, VC, and several other compounds still present. Attenuation of VC in the aerobic zone suggests that it is being biodegraded. In this study microcosms were used to evaluate the role of methane and ethene as primary substrates for aerobic biodegradation of VC. Biodegradation of VC was fastest in the bottles containing ethene, with 40 μmol of VC consumed over a 150 day period, compared to approximately 15–20 μmol with methane or a mixture of methane and ethene. VC did not noticeably inhibit ethene biodegradation but did slow the rate of methane use. Methane inhibited ethene metabolism, which apparently caused a reduction in VC biodegradation when methane was present with ethene. These results suggest that ethene plays an important role during in situ natural attenuation of VC under aerobic conditions. Microcosms were also set up with VC alone. Following a 75 day lag period, VC consumption began and subsequent additions were consumed without a lag, suggesting the presence of organisms capable of using VC as a growth substrate. After providing VC alone for nearly 400 days, aliquots of the enrichment culture were used to evaluate its ability to biodegrade cis- and trans-DCE. Both compounds were readily consumed, although addition of VC as the primary substrate was needed to sustain biodegradation of repeated additions. This result suggests that organisms capable of using VC as a sole substrate may play an active role in aerobic natural attenuation of DCEs.

scholarly journals Phylogenetic and Kinetic Diversity of Aerobic Vinyl Chloride-Assimilating Bacteria from Contaminated Sites

2002 ◽  
Vol 68 (12) ◽  
pp. 6162-6171 ◽  
Author(s):  
Nicholas V. Coleman ◽  
Timothy E. Mattes ◽  
James M. Gossett ◽  
Jim C. Spain
Keyword(s):  
Vinyl Chloride ◽  
Natural Attenuation ◽  
Chlorinated Solvents ◽  
Growth Yield ◽  
Substrate Utilization ◽  
Contaminated Sites ◽  
Utilization Rate ◽  
Specific Substrate ◽  
Monooxygenase Activity ◽  
Specific Growth Rates

ABSTRACT Aerobic bacteria that grow on vinyl chloride (VC) have been isolated previously, but their diversity and distribution are largely unknown. It is also unclear whether such bacteria contribute to the natural attenuation of VC at chlorinated-ethene-contaminated sites. We detected aerobic VC biodegradation in 23 of 37 microcosms and enrichments inoculated with samples from various sites. Twelve different bacteria (11 Mycobacterium strains and 1 Nocardioides strain) capable of growth on VC as the sole carbon source were isolated, and 5 representative strains were examined further. All the isolates grew on ethene in addition to VC and contained VC-inducible ethene monooxygenase activity. The Mycobacterium strains (JS60, JS61, JS616, and JS617) all had similar growth yields (5.4 to 6.6 g of protein/mol), maximum specific growth rates (0.17 to 0.23 day−1), and maximum specific substrate utilization rates (9 to 16 nmol/min/mg of protein) with VC. The Nocardioides strain (JS614) had a higher growth yield (10.3 g of protein/mol), growth rate (0.71 day−1), and substrate utilization rate (43 nmol/min/mg of protein) with VC but was much more sensitive to VC starvation. Half-velocity constant (Ks ) values for VC were between 0.5 and 3.2 μM, while Ks values for oxygen ranged from 0.03 to 0.3 mg/liter. Our results indicate that aerobic VC-degrading microorganisms (predominantly Mycobacterium strains) are widely distributed at sites contaminated with chlorinated solvents and are likely to be responsible for the natural attenuation of VC.

scholarly journals Identification of reductive dehalogenases that mediate complete debromination of penta- and tetra-brominated diphenyl ethers in Dehalococcoides

2021 ◽  
Author(s):  
Siyan Zhao ◽  
Matthew J. Rogers ◽  
Lifeng Cao ◽  
Chang Ding ◽  
Jianzhong He
Keyword(s):  
Vinyl Chloride ◽  
Polybrominated Diphenyl Ethers ◽  
Enrichment Culture ◽  
Diphenyl Ether ◽  
Contaminated Sites ◽  
Proteomic Profiling ◽  
Native Page ◽  
Dehalococcoides Mccartyi ◽  
Diphenyl Ethers

Polybrominated diphenyl ethers (PBDEs) are persistent, highly toxic, and widely distributed environmental pollutants. The microbial populations and functional reductive dehalogenases (RDases) responsible for PBDEs debromination in anoxic systems remain poorly understood, which confounds bioremediation of PBDE-contaminated sites. Here we report a PBDE-debrominating enrichment culture dominated by a previously undescribed Dehalococcoides mccartyi population. A D. mccartyi strain, designated TZ50, whose genome contains 25 putative RDase encoding genes, was isolated from the debrominating enrichment culture. Strain TZ50 dehalogenated a mixture of penta- and tetra-BDE congeners (total BDEs 1.48 μM) to diphenyl ether within two weeks (0.58 μM Br - /d) via o rtho - and meta - bromine elimination; strain TZ50 also dechlorinated tetrachloroethene (PCE) to vinyl chloride and ethene (260.2 μM Cl - /d). Results of native-PAGE, proteomic profiling, and in vitro enzymatic activity assays implicated involvement of three RDases in PBDEs and PCE dehalogenation. TZ50_0172 (PteA TZ50 ) and TZ50_1083 (TceA TZ50 ), were responsible for debromination of penta- and tetra-BDEs to di-BDE. TZ50_0172 and TZ50_1083 were also implicated in dechlorination of PCE to TCE and of TCE to vinyl chloride/ethene, respectively. The other expressed RDase, TZ50_0090 (designated BdeA), was associated with debromination of di-BDE to diphenyl ether, but its role in PCE dechlorination was unclear. Comparatively few RDases are known to be involved in PBDE debromination and the identification of PteA TZ50 , TceA TZ50 , and BdeA provides additional information for evaluating debromination potential at contaminated sites. Moreover, the ability of PteA TZ50 and TceA TZ50 to dehalogenate both PBDEs and PCE makes strain TZ50 a suitable candidate for remediation of co-contaminated sites. Importance The ubiquity, toxicity, and persistence of polybrominated diphenyl ethers (PBDEs) in the environment have drawn significant public and scientific interest to the need for remediation of PBDEs-contaminated ecosystems. However, the low bioavailability of PBDEs in environmental compartments typically limits bioremediation of PBDEs and has long impeded the study of anaerobic microbial PBDEs removal. In the current study, a novel Dehalococcoides mccartyi , dubbed strain TZ50, that expresses RDases that mediate organohalide respiration of both PBDEs and chloroethenes was isolated and characterized. Strain TZ50 could potentially be used to remediate multiple co-occurring organohalides in contaminated systems.

scholarly journals Deployment Plan for Bioremediation and Natural Attenuation for In Situ Restoration of Chloroethene-Contaminated Groundwater

1999 ◽  
Author(s):  
L.N. Peterson ◽  
R.C. Starr ◽  
K.S. Sorenson ◽  
R.W. Smith ◽  
T.J. Phelps
Keyword(s):  
Natural Attenuation ◽  
Contaminated Groundwater

On-site and in situ bioremediation of wood-preservative contaminated groundwater

2000 ◽  
Vol 42 (5-6) ◽  
pp. 371-376 ◽  
Author(s):  
J.A. Puhakka ◽  
K.T. Järvinen ◽  
J.H. Langwaldt ◽  
E.S. Melin ◽  
M.K. Männistö ◽  
...  
Keyword(s):  
Iron Oxidation ◽  
Wood Preservative ◽  
Pilot Scale ◽  
High Rate ◽  
Contaminated Groundwater ◽  
Groundwater Temperature ◽  
In Situ Bioremediation ◽  
Contaminated Aquifer ◽  
Fluidized Bed Process

This paper reviews ten years of research on on-site and in situ bioremediation of chlorophenol contaminated groundwater. Laboratory experiments on the development of a high-rate, fluidized-bed process resulted in a full-scale, pump-and-treat application which has operated for several years. The system operates at ambient groundwater temperature of 7 to 9°C at 2.7 d hydraulic retention time and chlorophenol removal efficiencies of 98.5 to 99.9%. The microbial ecology studies of the contaminated aquifer revealed a diverse chlorophenol-degrading community. In situ biodegradation of chlorophenols is controlled by oxygen availability, only. Laboratory and pilot-scale experiments showed the potential for in situ aquifer bioremediation with iron oxidation and precipitation as a potential problem.

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