Studies on the physiology of microbial degradation of pentachlorophenol

TLDR: The presence of ammonium salts enhanced the rate of PCP degradation without affecting the yield of CO2, and the optimum pH for degradation was from 6.4 to 7.2 and at higher pH value (8.4) degradation was inhibited more than at lower pH (5.6).

Abstract: The requirements and conditions for pentachlorophenol (PCP) biodegradation by a mixed bacterial culture was studied. The effects of oxygen, nutrients, additional carbon sources, pH and temperature are described. Up to 90% of PCP was degraded into CO2 and inorganic chloride in 1 week at an input concentration of <600 μM. Degradation continued when pO2 was lowered to 0.0002 atm but ceased when pO2 was further decreased to 0.00002 atm. Supplementary carbon sources, such as phenol, hydroxybenzoic acids or complex nutrients did not affect the biodegradation, but the presence of ammonium salts enhanced the rate of PCP degradation without affecting the yield of CO2. The degrading organisms were shown to be procaryotic mesophiles; no degradation was shown at temperatures below +8° and above +50°C. The optimum pH for degradation was from 6.4 to 7.2 and at higher pH value (8.4) degradation was inhibited more than at lower pH (5.6).