Phenol degradation by the marine cyanobacterium Phormidium valderianum BDU 30501

Bioremediation is a cost-effective alternative to conventional disposal methods and is a new technology which emphasizes the detoxification and destruction of the pollutants by acclimatized microorganisms. Cyanobacteria are in a more advantageous position than heterotrophic bacteria because of their trophic independence for nitrogen as well as carbon. Phenol, the toxic constituent of several industrial effluents, was found to be effectively removed and degraded by the marine cyanobacterium Phormidium valderianum BDU 30501. The organism was able to tolerate and grow at a phenol concentration of 50 mg L−1 and remove 38 mg L−1 within a retention period of 7 days. The removal and degradation were confirmed by changes in the ultraviolet absorption spectra in the culture filtrate, colorimetric estimation of residual phenol and measuring the intracellular activity of the inducible polyphenol oxidase and laccase enzymes. This opens up the possibility of treating a variety of phenol-containing industrial effluents using this organism.