Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1999-3-24
pubmed:abstractText
In this study we evaluated specific and nonspecific toxic effects of aeration and trichloroethylene (TCE) oxidation on methanotrophic bacteria grown with different nitrogen sources (nitrate, ammonia, and molecular nitrogen). The specific toxic effects, exerted directly on soluble methane monooxygenase (sMMO), were evaluated by comparing changes in methane uptake rates and naphthalene oxidation rates following aeration and/or TCE oxidation. Nonspecific toxic effects, defined as general cellular damage, were examined by using a combination of epifluorescent cellular stains to measure viable cell numbers based on respiratory activity and measuring formate oxidation activities following aeration and TCE transformation. Our results suggest that aeration damages predominantly sMMO rather than other general cellular components, whereas TCE oxidation exerts a broad range of toxic effects that damage both specific and nonspecific cellular functions. TCE oxidation caused sMMO-catalyzed activity and respiratory activity to decrease linearly with the amount of substrate degraded. Severe TCE oxidation toxicity resulted in total cessation of the methane, naphthalene, and formate oxidation activities and a 95% decrease in the respiratory activity of methanotrophs. The failure of cells to recover even after 7 days of incubation with methane suggests that cellular recovery following severe TCE product toxicity is not always possible. Our evidence suggests that generation of greater amounts of sMMO per cell due to nitrogen fixation may be responsible for enhanced TCE oxidation activities of nitrogen-fixing methanotrophs rather than enzymatic protection mechanisms associated with the nitrogenase enzymes.
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/9925614-1368139, http://linkedlifedata.com/resource/pubmed/commentcorrection/9925614-1622256, http://linkedlifedata.com/resource/pubmed/commentcorrection/9925614-1905516, http://linkedlifedata.com/resource/pubmed/commentcorrection/9925614-1908211, http://linkedlifedata.com/resource/pubmed/commentcorrection/9925614-2036009, http://linkedlifedata.com/resource/pubmed/commentcorrection/9925614-2036023, http://linkedlifedata.com/resource/pubmed/commentcorrection/9925614-2207083, http://linkedlifedata.com/resource/pubmed/commentcorrection/9925614-2542319, http://linkedlifedata.com/resource/pubmed/commentcorrection/9925614-3085587, http://linkedlifedata.com/resource/pubmed/commentcorrection/9925614-3919642, http://linkedlifedata.com/resource/pubmed/commentcorrection/9925614-5476891, http://linkedlifedata.com/resource/pubmed/commentcorrection/9925614-7618872, http://linkedlifedata.com/resource/pubmed/commentcorrection/9925614-8285688, http://linkedlifedata.com/resource/pubmed/commentcorrection/9925614-8801441, http://linkedlifedata.com/resource/pubmed/commentcorrection/9925614-9726896
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0099-2240
pubmed:author
pubmed:issnType
Print
pubmed:volume
65
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
766-72
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Evaluation of toxic effects of aeration and trichloroethylene oxidation on methanotrophic bacteria grown with different nitrogen sources.
pubmed:affiliation
Department of Civil and Environmental Engineering, University of California, Berkeley, California 94720-1710, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't