Potential Of Microbial Species In Biodegradation Of Volatile Organic Compounds From Waters

Environmental contamination by volatile organic compounds (VOCs) from petrochemical and energy-producing industries is continually increasing. Among VOCs, aromatic compounds such as benzene, toluene and xylenes are the most severe contaminants because of their increasing use as gasoline, aircraft fuel and solvent. Due to their low water solubility, acute toxicity and genotoxicity, these compounds are classified as priority pollutants by European Environment Agency. Bioremediation exploits the ability of microorganisms to reduce the concentration and/or toxicity of a large number of pollutants. It is an economical, versatile, environment-friendly efficient treatment, which has a greater public acceptance and support. In this study we investigated growth patterns of microbial strains during volatile organic compounds degradation in order to select organisms for most efficient biodegradation. The aerobic batch tests were performed with Pseudomonas putida, Candida membranes and Penicillium sp, strains screened previously from various microbial species. A minimal liquid medium containing volatile organic compounds as carbon source, single substrate or in binary and tertiary mixtures was used to evaluate degradation activity of microbial strains. The content of organic compounds was analyzed with gas chromatograph coupled with mass spectrometry. As summarized, the selected strains were able of growing and transforming the volatile organic compounds tested. It was shown that benzene is the most resistant towards microbial degradation, the substitution of aromatic ring in toluene and xylene have facilitated the microbial attack