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Effect of trichloroethylene loading on mixed methanotrophic community stability

Conference ·
OSTI ID:474274
; ;  [1]
  1. Univ. of Washington, Seattle, WA (United States)

There is concern that trichloroethylene (TCE) degradation by methanotrophic cultures cannot be maintained due to metabolite toxicity. The purpose of this research was to understand the effects of metabolite toxicity on methanotrophic cultures and to define operating conditions that might minimize these effects. A mixed methanotrophic culture was maintained with continuous supply of methane a/nd nutrients as TCE loading was increased from 4 to 10 {micro}g TCE/(mg protein-d). The maximum sustainable ratio of TCE degraded to methane consumed was 6 {micro}g TCE/mg methane. Biomass, methane consumption, and TCE degradation fell precipitously when the loading exceeded 10 {micro}g TCE/(mg-protein-d). Reactor failure was preceded by a fall in the soluble methane monooxygenase (sMMO) activities. Phospholipid fatty acid analyses of the biomass before and after failure indicated a shift from a type II to a type I methanotrophic culture, a change that suggests a decreased ability to cometabolize TCE. These results suggest that continued exposure of a mixed methanotrophic culture to levels of TCE that damage cell viability can result in loss of cometabolic capabilities and a change in the population of the methanotrophic culture.

OSTI ID:
474274
Report Number(s):
CONF-950483--; ISBN 1-57477-005-5
Country of Publication:
United States
Language:
English