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.

Development of hexachlorobenzene-dechlorinating mixed cultures using polysorbate surfactants as a carbon source

2001 ◽  
Vol 43 (2) ◽  
pp. 43-50 ◽  
Author(s):  
D. H. Yeh ◽  
S. G. Pavlostathis
Keyword(s):  
Carbon Source ◽  
Reductive Dechlorination ◽  
Sole Carbon Source ◽  
Microbial Reductive Dechlorination ◽  
Feeding Cycle ◽  
One Year ◽  
Enriched Cultures ◽  
Tween 60 ◽  
Polychlorinated Organic Compounds

The use of three nonionic polysorbate surfactants – Tween 60, 61 or 65 – as the sole carbon source to sustain methanogenesis and dechlorination, as well as the effect of long-term exposure of enriched cultures to these surfactants, was investigated through the development of three sediment-derived cultures. Over a one-year period, the carbon source in these cultures was gradually switched from glucose and methanol to surfactant only, while the surfactant concentration was increased from an initial concentration of 100 mg/L to 400 mg/L. In each feeding cycle, the surfactants were partially degraded and converted to methane. Transition from glucose to Tween surfactants as the electron donor did not affect the rate, extent, and pathway of HCB transformation. These surfactants sustained the reductive dechlorination of HCB even after one year of continuous addition to the enriched cultures. This study demonstrated that reductive dechlorination of HCB sustained by the fermentation of Tween surfactants is feasible. The results support the use of anaerobically degradable Tween surfactants for the biotransformation of polychlorinated organic compounds. In principle, these surfactants could be used to simultaneously increase the bioavailability of subsurface contaminants while serving as the carbon and electron source for microbial reductive dechlorination.

The effect of volatile fatty acids as a sole carbon source on lipid accumulation by Cryptococcus albidus for biodiesel production

2011 ◽  
Vol 102 (3) ◽  
pp. 2695-2701 ◽  
Author(s):  
Qiang Fei ◽  
Ho Nam Chang ◽  
Longan Shang ◽  
Jin-dal-rae Choi ◽  
NagJong Kim ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Carbon Source ◽  
Lipid Accumulation ◽  
Sole Carbon Source ◽  
Volatile Fatty Acids ◽  
Biodiesel Production ◽  
Cryptococcus Albidus

scholarly journals Pandrug-resistant Pseudomonas sp. expresses New Delhi metallo-β-lactamase-1 and consumes ampicillin as sole carbon source

2020 ◽  
Author(s):  
Vivek Kumar Ranjan ◽  
Shriparna Mukherjee ◽  
Subarna Thakur ◽  
Krutika Gupta ◽  
Ranadhir Chakraborty
Keyword(s):  
Carbon Source ◽  
Sole Carbon Source ◽  
New Delhi ◽  
Pseudomonas Sp

scholarly journals Study of a plugging microbial consortium using crude oil as sole carbon source

2008 ◽  
Vol 5 (4) ◽  
pp. 367-374 ◽  
Author(s):  
Jing Wang ◽  
Guiwen Yan ◽  
Mingquan An ◽  
Jieli Liu ◽  
Houming Zhang ◽  
...  
Keyword(s):  
Carbon Source ◽  
Crude Oil ◽  
Sole Carbon Source ◽  
Microbial Consortium

Characterization of humins from different natural sources and the effect on microbial reductive dechlorination of pentachlorophenol

Chemosphere ◽  
2015 ◽  
Vol 131 ◽  
pp. 110-116 ◽  
Author(s):  
Chunfang Zhang ◽  
Dongdong Zhang ◽  
Zhixing Xiao ◽  
Zhiling Li ◽  
Daisuke Suzuki ◽  
...  
Keyword(s):  
Reductive Dechlorination ◽  
Natural Sources ◽  
Microbial Reductive Dechlorination

Changes in Enantiomeric Fractions during Microbial Reductive Dechlorination of PCB132, PCB149, and Aroclor 1254 in Lake Hartwell Sediment Microcosms

2003 ◽  
Vol 37 (6) ◽  
pp. 1100-1107 ◽  
Author(s):  
Usarat Pakdeesusuk ◽  
W. Jack Jones ◽  
Cindy M. Lee ◽  
Arthur W. Garrison ◽  
Walter L. O'Niell ◽  
...  
Keyword(s):  
Reductive Dechlorination ◽  
Aroclor 1254 ◽  
Microbial Reductive Dechlorination ◽  
Lake Hartwell

scholarly journals Mutants affecting histidine utilization inAspergillus nidulans

1975 ◽  
Vol 25 (2) ◽  
pp. 119-135 ◽  
Author(s):  
Meryl Polkinghorne ◽  
M. J. Hynes
Keyword(s):  
Carbon Source ◽  
Nitrogen Source ◽  
Sole Carbon Source ◽  
Nitrogen Sources ◽  
Limiting Factor ◽  
Sole Nitrogen Source ◽  
Wild Type ◽  
Exogenous Substrate ◽  
Growth Properties ◽  
Type Strains

SUMMARYWild-type strains ofAspergillus nidulansgrow poorly onL-histidine as a sole nitrogen source. The synthesis of the enzyme histidase (EC. 4.3.1.3) appears to be a limiting factor in the growth of the wild type, as strains carrying the mutantareA102 allele have elevated histidase levels and grow strongly on histidine as a sole nitrogen source.L-Histidine is an extremely weak sole carbon source for all strains.Ammonium repression has an important role in the regulation of histidase synthesis and the relief of ammonium repression is dependent on the availability of a good carbon source. The level of histidase synthesis does not respond to the addition of exogenous substrate.Mutants carrying lesions in thesarA orsarB loci (suppressor ofareA102) have been isolated. The growth properties of these mutants on histidine as a sole nitrogen source correlate with the levels of histidase synthesized. Mutation at thesarA andsarB loci also reduces the utilization of a number of other nitrogen sources. The data suggest that these two genes may code for regulatory products involved in nitrogen catabolism. No histidase structural gene mutants were identified and possible explanations of this are discussed.

Isolation of alcohol oxidase and two other methanol regulatable genes from the yeast Pichia pastoris

1985 ◽  
Vol 5 (5) ◽  
pp. 1111-1121
Author(s):  
S B Ellis ◽  
P F Brust ◽  
P J Koutz ◽  
A F Waters ◽  
M M Harpold ◽  
...  
Keyword(s):  
Pichia Pastoris ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Alcohol Oxidase ◽  
Methylotrophic Yeasts ◽  
Sequence Analyses ◽  
Yeast Pichia Pastoris ◽  
Oxidation Of Methanol ◽  
Regulated Expression

The oxidation of methanol follows a well-defined pathway and is similar for several methylotrophic yeasts. The use of methanol as the sole carbon source for the growth of Pichia pastoris stimulates the expression of a family of genes. Three methanol-responsive genes have been isolated; cDNA copies have been made from mRNAs of these genes, and the protein products from in vitro translations have been examined. The identification of alcohol oxidase as one of the cloned, methanol-regulated genes has been made by enzymatic, immunological, and sequence analyses. Methanol-regulated expression of each of these three isolated genes can be demonstrated to occur at the level of transcription. Finally, DNA subfragments of two of the methanol-responsive genomic clones from P. pastoris have been isolated and tentatively identified as containing the control regions involved in methanol regulation.

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