Biotransformation rates of chloroform under anaerobic conditions—II. Sulfate reduction

Gupta, M. P.; Gupta, Ashutosh; Suidan, Makram T.; Sayles, Gregory D.

doi:10.1016/0043-1354(96)00006-1

Cited by 25 publications

(20 citation statements)

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“…Although aerobic biotransformation of CF is possible (e.g., cometabolism by a butane-grown strain) (14), CF is more difficult to cometabolize than trichloroethene (42). Biotransformation of CF by mixed or pure cultures under methanogenic (5,21) and sulfate-reducing (20) conditions has been reported, however, only at low-mg/liter CF concentrations.…”

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confidence: 99%

Anaerobic Biotransformation of High Concentrations of Chloroform by an Enrichment Culture and Two Bacterial Isolates

Shan¹,

Kurtz

Mykytczuk

et al. 2010

Appl Environ Microbiol

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A fermentative enrichment culture (designated DHM-1) was developed that is capable of cometabolically biotransforming high concentrations of chloroform (CF) to nontoxic end products. Two Pantoea spp. were isolated from DHM-1 that also possess this dechlorination capability. Following acclimation to increasing levels of CF, corn syrup-grown DHM-1 was able to transform over 500 mg/liter CF in the presence of vitamin B 12 (approximately 3% of CF on a molar basis) at a rate as high as 22 mg/liter/day in a mineral salts medium. CO, CO 2 , and organic acids were the predominant biodegradation products, suggesting that hydrolytic reactions predominate during CF transformation. DHM-1 was capable of growing on corn syrup in the presence of high concentrations of CF (as may be present near contaminant source zones in groundwater), which makes it a promising culture for bioaugmentation. Strains DHM-1B and DHM-1T transform CF at rates similar to that of the DHM-1 enrichment culture. The ability of these strains to grow in the presence of high concentrations of CF appears to be related to alteration of membrane fluidity or homeoviscous and homeophasic adaptation.Chloroform (CF) is a toxic organic compound that is frequently detected in groundwater. In the 2007 "CERCLA Priority List of Hazardous Substances," CF ranks eleventh overall and is the third highest among chlorinated organics after vinyl chloride and polychlorinated biphenyls (4). When present at hazardous waste sites, CF is often a focal point for evaluating the feasibility of bioremediation, since it is toxic to many obligate anaerobic prokaryotes (44). For example, 1 mg/liter of CF completely inhibited dechlorination of tetrachloroethene (PCE) by a chlororespiring anaerobic isolate (32). Inhibition of reductive dechlorination of chloroethenes by CF is a general problem for sites cocontaminated with CF, which can only be overcome by first removing the CF (6).In spite of major recent advances in bioremediation of chlorinated organic compounds, treatment of CF, especially at high concentrations (e.g., Ͼ100 mg/liter), remains challenging. Although aerobic biotransformation of CF is possible (e.g., cometabolism by a butane-grown strain) (14), CF is more difficult to cometabolize than trichloroethene (42). Biotransformation of CF by mixed or pure cultures under methanogenic (5, 21) and sulfate-reducing (20) conditions has been reported, however, only at low-mg/liter CF concentrations.Corrinoids such as vitamin B 12 (i.e., cyanocobalamin) are effective catalysts for increasing the rate of halomethane biotransformation under anaerobic conditions. Addition of vitamin B 12 also shifts the pathway away from reductive dechlorination and toward hydrolytic and substitutive reactions, forming CO, CO 2 , and organic acids as the major products (8,23,24). With low levels of B 12 added (3 to 5% molar ratios of CF), an enrichment culture grown on dichloromethane (DCM) as the sole substrate (8) and a lactate-grown sulfate-reducing enrichment culture (18) were able to biotransform up ...

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confidence: 99%

Anaerobic Biotransformation of High Concentrations of Chloroform by an Enrichment Culture and Two Bacterial Isolates

Shan¹,

Kurtz

Mykytczuk

et al. 2010

Appl Environ Microbiol

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“…In anaerobic bioreactors, CT is converted to CF, DCM and other unidentified products (de Best et al 1997a). Under similar conditions CF is converted to DCM (Gupta et al 1996). Bouwer & McCarty (1983) observed that a large fraction of radiolabeled CT and CF was converted to CO 2 in anaerobic bioreactors indicating the occurrence of alternative processes other than reductive hydrogenolysis.…”

Section: Degradation Of Higher Chlorinated Methanes In Engineered Sysmentioning

confidence: 89%

“…reducing conditions (Gupta et al 1996). In an anaerobic chemostat operated under methanogenic conditions, CF degradation was 78 g m )3 reactor d )1 with propionate as primary substrate (Rhee & Speece 2000).…”

Section: Degradation Of Higher Chlorinated Methanes In Engineered Sysmentioning

confidence: 99%

“…a -Egli et al (1990); b -Krone et al (1989); c -Yu & Smith (1997); d -Gupta et al (1996); e -Yu et al (1997); f -Speitel et al (1993); g -Aziz et al (1999); h -Ely et al (1997); i -Alvarez-Cohen & McCarty (1991)a; j -Boopathy (2002); k -van Eekert et al (1998); l -Rhee & Speece (2000); m -Rhee & Speece (2000); n -Sponza (2002); o -Doong & Wu (1996); p -Egli et al (1990).…”

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confidence: 98%

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Biodegradability of chlorinated solvents and related chlorinated aliphatic compounds

Field

Sierra-Álvarez

2004

Rev Environ Sci Biotechnol

130

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The biodegradability of chlorinated methanes, chlorinated ethanes, chlorinated ethenes, chlorofluorocarbons (CFCs), chlorinated acetic acids, chlorinated propanoids and chlorinated butadienes was evaluated based on literature data. Evidence for the biodegradation of compounds in all of the compound categories evaluated has been reported. A broad range of chlorinated aliphatic structures are susceptible to biodegradation under a variety of physiological and redox conditions. Microbial biodegradation of a wide variety of chlorinated aliphatic compounds was shown to occur under five physiological conditions. However, any given physiological condition could only act upon a subset of the chlorinated compounds. Firstly, chlorinated compounds are used as an electron donor and carbon source under aerobic conditions. Secondly, chlorinated compounds are cometabolized under aerobic conditions while the microorganisms are growing (or otherwise already have grown) on another primary substrate. Thirdly, chlorinated compounds are also degraded under anaerobic conditions in which they are utilized as an electron donor and carbon source. Fourthly, chlorinated compounds can serve as an electron acceptor to support respiration of anaerobic microorganisms utilizing simple electron donating substrates. Lastly chlorinated compounds are subject to anaerobic cometabolism becoming biotransformed while the microorganisms grow on other primary substrate or electron acceptor. The literature survey demonstrates that, in many cases, chlorinated compounds are completely mineralised to benign end products. Additionally, biodegradation can occur rapidly. Growth rates exceeding 1 d )1 were observed for many compounds. Most compound categories include chlorinated structures that are used to support microbial growth. Growth can be due to the use of the chlorinated compound as an electron donor or alternatively to the use of the chlorinated compound as an electron acceptor (halorespiration). Biodegradation linked to growth is important, since under such conditions, rates of degradation will increase as the microbial population (biocatalyst) increases. Combinations of redox conditions are favorable for the biodegradation of highly chlorinated structures that are recalcitrant to degradation under aerobic conditions. However, under anaerobic conditions, highly chlorinated structures are partially dehalogenated to lower chlorinated counterparts. The lower chlorinated compounds are subsequently more readily mineralized under aerobic conditions.Abbreviations: A

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“…Though the mechanisms have yet to be determined, acclimation to toxic or inhibitory conditions in continuous cultures or a shift in the microbial community is possible. Acclimation to toxicity in continuous cultures has been previously observed (Gupta et al, 1996;Piringer and Bhattacharya, 1999;Qu and Bhattacharya, 1996). The K t,cDCE toxicity coefficient was therefore adjusted to reflect the observed TCE accumulation and cDCE decline beginning after day 56.…”

Section: Cfstr Modelingmentioning

confidence: 99%

Trichloroethene and cis‐1,2‐dichloroethene concentration‐dependent toxicity model simulates anaerobic dechlorination at high concentrations. II: Continuous flow and attached growth reactors

Sabalowsky¹,

Semprini²

2010

Biotech & Bioengineering

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A model that was used to describe toxicity from high concentrations of chlorinated aliphatic hydrocarbons (CAHs) on reductively dechlorinating cultures in batch reactors (Sabalowsky and Semprini (in press)) was extended here to simulate observations in continuous flow suspended and attached growth reactors. The reductively dechlorinating anaerobic Evanite subculture (EV-cDCE) was fed trichloroethene (TCE) and excess electron donor to accumulate cis-1,2-dichloroethene (cDCE) in a continuous flow stirred tank reactor (CFSTR); and an attached growth recirculating packed column (RPC). A concentration-dependent toxicity model used to simulate the results of batch reactors in part I (Sabalowsky and Semprini (in press) Biotechnol Bioeng) also simulated well the observations for the CFSTR and RPC growth modes. The toxicity model incorporates cDCE and TCE toxicity coefficients that directly increase the cell decay coefficient in proportion with cDCE and TCE concentrations. Simulated estimates of the cDCE and TCE toxicity coefficients indicate reductively dechlorinating cells are most sensitive to high concentrations of cDCE and TCE in batch-fed growth, followed by CFSTR, with attached growth being least sensitive. The greater toxicity of TCE than cDCE, and ratio of the modeled toxicity coefficients, agrees with previously proposed models relating toxicity to partitioning in the cell wall (K(M/B)), proportional to octanol-water partitioning (K(OW)) coefficients.

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Biotransformation rates of chloroform under anaerobic conditions—II. Sulfate reduction

Cited by 25 publications

References 10 publications

Anaerobic Biotransformation of High Concentrations of Chloroform by an Enrichment Culture and Two Bacterial Isolates

Anaerobic Biotransformation of High Concentrations of Chloroform by an Enrichment Culture and Two Bacterial Isolates

Biodegradability of chlorinated solvents and related chlorinated aliphatic compounds

Trichloroethene and cis‐1,2‐dichloroethene concentration‐dependent toxicity model simulates anaerobic dechlorination at high concentrations. II: Continuous flow and attached growth reactors

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