Growth Optimization of Naphthalene-Degrading Pseudomonas Stutzeri Strain BUK_BTEG1 Isolated from Petrochemical Contaminated Soil
Abstract:Bioremediation of PAHs such as naphthalene by the activity of microorganisms represents an eco-friendly, economical, and safe decontamination approach compared physical and chemical processes. In this study, the biodegradation conditions for naphthalene by Pseudomonas stutzeri strain BUK_BTEG1 was optimized through on factor-at-a-time (OFAT). The Characterization was conducted by studying the effect of incubation time, nitrogen source, pH, inoculum size, substrate concentration and temperature in BH media containing naphthalene as sole source of carbon and energy. The growth and degradation of naphthalene by this strain was optimal at 1000 mg/L ammonium Nitrate, substrate concentration of 800mg/L, temperature of 35 °C, pH of 7.0, inoculum size of 4% (v/v) and 72 hours of incubation time. After 72 hours of incubation under optimal conditions, the degradation efficiency of this strain to naphthalene was 72%. The analysis using gas chromatography-mass spectrometry reveals 1,2-naphthalenediol, 1-hydroxy-napthoic acid, 1,4-Napthoquinone, salicylic acid, and catechol as metabolites of naphthalene degradation by comparing the fragmentation pattern and mass spectrum obtained with data available on NIST library. This strain demonstrates promising potential and could be handy for its application in the bioremediation of naphthalene contaminated sites.