Degradation of Phenols Using Bacteria Isolated from the Subsurface of Manufactured Gas Plants

ABSTRACT

Microorganisms capable of degrading a variety of phenolic compounds have been successfully isolated from the subsurface of two former manufactured gas plant sites. The degradative capability of a single Psuedomonad isolate and a mixed microbial culture was assessed using a variety of phenols thought to be representative of those encountered on a former manufactured gas plant site. They included phenol, cresols, dimethylphenols and trimethylphenols. Degradation studies utilised a liquid based medium and degradation was assessed using high performance liquid chromatography. Phenol and the cresols were consistently removed with mineralisation rates of up to 99.9%. The degradation of the dimethyl and trimethylphenol was less predictable although mineralisation rates of up to 99% were also observed. The production and accumulation of metabolites was also noted in some instances. Degradation rates were analysed using linear regression. Zero and first order kinetics described the removal of the phenols with correlation coefficients of r = 0.73 to 1.00 and r = 0.74 to 1.00 respectively.