The use of microorganisms to degrade PCBs from contaminated sites, relying on multiple microorganisms co-metabolism, is known as bioremediation of polychlorinated biphenyl. Some micro-organisms degrade PCBs by reducing the C-Cl bonds. Microbial dechlorination tends to be rather slow-acting in comparison to other methods. Enzymes extracted from microbes can show PCB activity. In 2005, Shewanella oneidensis' biodegraded a high percentage of PCBs in soil samples. A low voltage current can stimulate the microbial degradation of PCBs.