Mineralization of Trichloroethylene by Heterotrophic Enrichment Cultures

Abstract

Microbial consortia capable of aerobically degrading more than 99% of exogenous trichloroethylene (TCE) (50 mg/liter) were collected from TCE-contaminated subsurface sediments and grown in enrichment cultures. TCE at concentrations greater than 300 mg/liter was not degraded, nor was TCE used by the consortia as a sole energy source. Energy sources which permitted growth included tryptone-yeast extract, methanol, methane, and propane. The optimum temperautre range for growth and subsequent TCE consumption was 22 to 37.degree. C, and the pH optimum was 7.0 to 8.1. Utilization of TCE occurred only after apparent microbial growth had ceased. The major end products recovered were hydrochloric acid and carobn dioxide. Minor products included dichloroethylene, vinylidine chlioride, and, possibly, chloroform.