Study of the reductive dechlorination of pentachlorophenol by a methanogenic consortium

1995 ◽  
Vol 41 (10) ◽  
pp. 862-868 ◽  
Author(s):  
P. Juteau ◽  
R. Beaudet ◽  
G. McSween ◽  
F. Lépine ◽  
J.-G. Bisaillon
Keyword(s):  
Heat Treatment ◽  
Carbon Source ◽  
Yeast Extract ◽  
Reductive Dechlorination ◽  
Para Position ◽  
Vigorous Agitation ◽  
Good Substrate ◽  
Spore Forming Bacteria ◽  
Methanogenic Consortium ◽  
Secondary Carbon

Pentachlorophenol (PCP) dechlorination by a methanogenic consortium was observed when glucose, formate, lactate, or yeast extract was present in the mineral medium as a secondary carbon source. Acetate was not a good substrate to sustain dechlorination. The consortium was able to dechlorinate the different monochlorophenols, although the chlorine in position ortho and meta was removed more readily than in para position. Dechlorination was most efficient at 37 °C. At 45 °C, the first PCP dechlorination steps were very rapid, but 3,5-dichlorophenol (3,5-DCP) was not further dechlorinated. At 15 and 4 °C, dechlorination was very slow. The dechlorination of PCP to 3-chlorophenol (3-CP) was still observed after the consortium had been subjected to heat treatment (80 °C, 60 min), suggesting that spore-forming bacteria were responsible. The dechlorinating activity of the consortium was significantly reduced by the presence of hydrogen, 2-bromoethanosulfonic acid (BESA), or sulfate but not of nitrate. The dechlorination of 3-CP was completely inhibited by heat treatment or the presence of BESA, suggesting that a syntrophic microorganism would be involved. Vigorous agitation of the consortium stopped the dechlorination, but the presence of DEAE-Sephacel acting as a support was very efficient in restoring the activity, suggesting that association between certain members of the consortium was important.Key words: pentachlorophenol, dechlorination, anaerobic, methanogenesis.

scholarly journals Lipid accumulation capability of typical non‐acclimated activated sludge microbial consortia using methane gas as secondary carbon source

2020 ◽  
Vol 2 (4) ◽  
Author(s):  
Dhan Lord B. Fortela ◽  
Wayne Sharp ◽  
Emmanuel Revellame ◽  
Andrei Chistoserdov ◽  
William Holmes ◽  
...  
Keyword(s):  
Carbon Source ◽  
Activated Sludge ◽  
Lipid Accumulation ◽  
Microbial Consortia ◽  
Methane Gas ◽  
Acclimated Activated Sludge ◽  
Secondary Carbon

Citrus Residues Isolates Improve Astaxanthin Production by Xanthophyllomyces dendrorhous

2010 ◽  
Vol 65 (9-10) ◽  
pp. 594-598 ◽  
Author(s):  
Wei Wu ◽  
Mingbo Lu ◽  
Longjiang Yu
Keyword(s):  
Carbon Source ◽  
Yeast Extract ◽  
Minimal Medium ◽  
Wild Strain ◽  
Xanthophyllomyces Dendrorhous ◽  
Citrus Juice ◽  
Astaxanthin Production ◽  
Mutant Strains

The wild strain and two astaxanthin-overproducing mutant strains, W618 and GNG274, of Xanthophyllomyces dendrorhous were analyzed in order to assess their ability to grow and synthesize astaxanthin in a minimal medium containing (per liter): 2 g KH2PO4, 0.5 g MgSO4, 2 g KNO3, and 1 g yeast extract, and supplemented with citrus residues isolates as a carbon source (citrus medium). The selected strain W618 was evaluated under various contents of citrus juice. At the content of 20% (v/v), the highest astaxanthin production reached 22.63 mg L-1, which was two-fold more than that observed in yeast malt medium. Addition of 8% (v/v) n-hexadecane to the citrus medium was found to be optimal, increasing the astaxanthin yield by 21.7%.

The Effects of the Secondary Carbon Source on the Biodegradation of Chlorinated Phenols in Biofilm Reactors

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2113-2116 ◽  
Author(s):  
C. J. Lu ◽  
S. J. Chen
Keyword(s):  
Carbon Source ◽  
Batch Reactors ◽  
Chlorinated Phenols ◽  
Biofilm Reactors ◽  
Secondary Carbon

The effects of the presence of a secondary carbon source on the biodegradation of chlorinated phenols were studied with column biofilm reactors. The biodegradability of chlorinated phenols was studied with a series of batch reactors. The biodegradability of chlorinated phenols was to follow the order of phenol > 2,4-dichlorophenol > 4-chIorophenol > 2,4,6-trichlorophenol > 2-chlorophenol > 3-chloro-phenol. The presence of a relatively more biodegradable but higher chlorinated phenol, such as 2,4,6-trichlorophenol, enhanced the biodégradation of a less chlorinated butrecalcitrantphenol, such as 2-chlorophenol. The addition of phenol, an easily biodegradable compound, generally decreased the biodegradation of chlorinated phenols.

scholarly journals Reductive, Coenzyme A-Mediated Pathway for 3-Chlorobenzoate Degradation in the Phototrophic BacteriumRhodopseudomonas palustris

2001 ◽  
Vol 67 (3) ◽  
pp. 1396-1399 ◽  
Author(s):  
Paul G. Egland ◽  
Jane Gibson ◽  
Caroline S. Harwood
Keyword(s):  
Carbon Dioxide ◽  
Carbon Source ◽  
Reductive Dechlorination ◽  
Coenzyme A ◽  
Rhodopseudomonas Palustris ◽  
Aromatic Acid ◽  
Enzyme Assays ◽  
Acetyl Coa ◽  
Selective Enrichment ◽  
Anaerobic Dechlorination

ABSTRACT We isolated a strain of Rhodopseudomonas palustris(RCB100) by selective enrichment in light on 3-chlorobenzoate to investigate the steps that it uses to accomplish anaerobic dechlorination. Analyses of metabolite pools as well as enzyme assays suggest that R. palustris grows on 3-chlorobenzoate by (i) converting it to 3-chlorobenzoyl coenzyme A (3-chlorobenzoyl–CoA), (ii) reductively dehalogenating 3-chlorobenzoyl–CoA to benzoyl-CoA, and (iii) degrading benzoyl-CoA to acetyl-CoA and carbon dioxide.R. palustris uses 3-chlorobenzoate only as a carbon source and thus incorporates the acetyl-CoA that is produced into cell material. The reductive dechlorination route used by R. palustris for 3-chlorobenzoate degradation differs from those previously described in that a CoA thioester, rather than an unmodified aromatic acid, is the substrate for complete dehalogenation.

Research on the Isolation, Identification and Degradation Characteristics of a Diesel Oil Degrading Strain

2013 ◽  
Vol 641-642 ◽  
pp. 206-210 ◽  
Author(s):  
Lei Huang ◽  
Jing Xie ◽  
Xiao Feng Shi ◽  
Jing Yan Lian
Keyword(s):  
Carbon Source ◽  
Yeast Extract ◽  
Contaminated Soils ◽  
Biomass Concentration ◽  
Diesel Oil ◽  
Artificial Seawater ◽  
Oil Field ◽  
Optimal Concentration ◽  
Optimal Temperature

A hydrocarbon-degrading strain ZRS was isolated from petroleum-contaminated soils sampled from Xinjiang oil field and identified as Acinetobacter beijerinckii, which could use diesel oil as solo carbon source. The optimal temperature and pH for strain utilizing ethanol was 25°C and 7.2; the optimal concentration of ethanol and the biomass concentration was 4.5% and 109 CFU/mL, respectively. Inoculated to artificial seawater which added (NH4)2SO4 2.64g/L、Na2HPO4 1.5 g/L and yeast extract 13 mg/L after 7 days of culture at temperature 25°C, the rate of degradation was 73.9％.

scholarly journals Production of Polyhydroxyalkanoates (PHAs) by Vibrio alginolyticus Strains Isolated from Salt Fields

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6283
Author(s):  
Hong-Fei Li ◽  
Meng-Ru Wang ◽  
Lin-Yue Tian ◽  
Zheng-Jun Li
Keyword(s):  
Carbon Source ◽  
Organic Acids ◽  
Water Samples ◽  
Opportunistic Pathogen ◽  
Vibrio Alginolyticus ◽  
Culture Temperature ◽  
Waste Glycerol ◽  
Nacl Concentration ◽  
Pha Production ◽  
Secondary Carbon

Vibrio alginolyticus is a halophilic organism usually found in marine environments. It has attracted attention as an opportunistic pathogen of aquatic animals and humans, but there are very few reports on polyhydroxyalkanoate (PHA) production using V. alginolyticus as the host. In this study, two V. alginolyticus strains, LHF01 and LHF02, isolated from water samples collected from salt fields were found to produce poly(3-hydroxybutyrate) (PHB) from a variety of sugars and organic acids. Glycerol was the best carbon source and yielded the highest PHB titer in both strains. Further optimization of the NaCl concentration and culture temperature improved the PHB titer from 1.87 to 5.08 g/L in V. alginolyticus LHF01. In addition, the use of propionate as a secondary carbon source resulted in the production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). V. alginolyticus LHF01 may be a promising host for PHA production using cheap waste glycerol from biodiesel refining.

Anaerobic biodegradability of Tween surfactants used as a carbon source for the microbial reductive dechlorination of hexachlorobenzene

2005 ◽  
Vol 52 (1-2) ◽  
pp. 343-349 ◽  
Author(s):  
D.H. Yeh ◽  
S.G. Pavlostathis
Keyword(s):  
Carbon Source ◽  
Reductive Dechlorination ◽  
Sole Carbon Source ◽  
Volatile Fatty Acids ◽  
Anaerobic Biodegradation ◽  
Hydrophobic Moiety ◽  
Anaerobic Biodegradability ◽  
Microbial Reductive Dechlorination ◽  
Acetate Accumulation ◽  
Tween 60

Three structurally-related, nonionic, polysorbate surfactants (Tween 60, 61, and 65) were used as the sole carbon source to sustain the microbial, sequential reductive dechlorination of hexachlorobenzene (HCB) in a mixed, methanogenic culture derived from a contaminated estuarine sediment. The surfactants were partially degraded and fermented to methane with no measurable accumulation of volatile fatty acids, indicating that methanogenesis was rapid relative to the rates of hydrolysis and acidogenesis. Addition of the methanogenesis inhibitor 2-bromoethanesulfonic acid resulted in acetate accumulation without impact on the sequential dechlorination of HCB. An anaerobic biodegradability assay was performed and the following data were obtained for the Tween 60, 61, and 65, respectively: 53, 62, and 62% COD destruction; 35, 57, and 48% COD to methane conversion; and 38, 38, and 45% COD to acetate conversion. These data suggest that the hydrophobic moiety (stearate) of the surfactants was preferentially degraded, most likely through β-oxidation, to acetate and ultimately to methane and carbon dioxide. Between 38 and 47% of the initial surfactant COD remained after 46 d incubation, which most likely corresponds to the hydrophilic polyoxyethylene moiety. An anaerobic biodegradation pathway of the Tween surfactants is proposed.

scholarly journals Evaluation of biobutanol production by Clostridium beijerinckii NRRL B-592 using sweet sorghum as carbon source

2015 ◽  
Vol 45 (9) ◽  
pp. 1707-1712 ◽  
Author(s):  
Luiz Jardel Visioli ◽  
Eliana Albornoz Alves ◽  
Aline Trindade ◽  
Raquel Cristine Kuhn ◽  
Marcio Schwaab ◽  
...  
Keyword(s):  
Carbon Source ◽  
Yeast Extract ◽  
Sweet Sorghum ◽  
Low Cost ◽  
Inoculum Size ◽  
Clostridium Beijerinckii ◽  
Initial Inoculum ◽  
Sweet Sorghum Juice ◽  
Operational Variables ◽  
Initial Ph

<p>In this research it was evaluated the production of biobutanol by<bold> Clostridium beijerinckii</bold>NRRL B-592 using sweet sorghum juice as carbon source. Operational variables, like pH and initial inoculum size, as well as supplementation of industrial media with yeast extract and tryptone, were evaluated. The maximum butanol obtained was 2.12g kg<sup>-1</sup> using 12.5% of inoculum size, 0.05g 100mL<sup>-1</sup> of tryptone and 0.1g 100mL<sup>-1</sup> of yeast extract and initial pH of 5.5. The main contribution of this research was to show a systematic procedure for development of a low cost industrial media for biobutanol production from sweet sorghum.</p>

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