Ecology, Environment and Conservation Paper

ISOLATION, GENETIC IDENTIFICATION AND OPTIMIZATION OF HYDROCARBON DEGRADING BACTERIA FROM PETROLEUM CONTAMINATED SOIL IN RAIGAD REGION

R.D. Nanekar and S.S. Kokitkar

Abstract

In recent years, accumulation of petroleum hydrocarbons in soil and water is a global concern due to its genotoxicity and carcinogenic nature. Bioremediation of petroleum contaminates sites with natural isolates having ability to degrade hydrocarbons, are safe alternative for effective biodegradation. Present study is focused on isolation, characterization and optimization of novel isolates from petroleum contaminated soil with hydrocarbon degrading potential. Thirteen different petroleum contaminated soil sites were sampled from Raigad region to isolate indigenous hydrocarbon degrading bacteria. DCPIP screening assay was performed to select best isolates which utilize hydrocarbon as carbon source. The two best isolates S9D2 and S13D1 were identified as Rhodococcus ruber and Azospirillum zeae respectively by 16S rRNA gene-based sequencing and Phylogenetic analysis. One factor at a time (OFAT) with a spectrophotometer approach was used to optimize growth parameter. Optimum growth of Rhodococcus ruber was observed with 2 % diesel concentration at 37 °C temperature and pH 7.0, while Azospirillum zeae showed better growth at 1% substrate concentration, pH 6.0. and temperature 30 °C. The current study revealed that both the isolates have ability to degrade hydrocarbons present in diesel, and can be used for effective bioremediation tools.