Recent research has focused on the in-place remediation of trichloroethylene in soil and groundwater using potassium permanganate instead of removal for off-site treatment and disposal. Naturally occurring bacteria have been identified with the ability to degrade TCE. Dehalococcoides sp. degrade trichloroethylene by reductive dechlorination under anaerobic conditions. Under aerobic conditions, Pseudomonas fluorescens can co-metabolize TCE. Soil and groundwater contamination by TCE has also been successfully remediated by chemical treatment and extraction. The bacteria Nitrosomonas europaea can degrade a variety of halogenated compounds including trichloroethylene. Toluene dioxygenase has been reported to be involved in TCE degradation by Pseudomonas putida. In some cases, Xanthobacter autotrophicus can convert up to 51% of TCE to CO and .