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Updated: Oct 11, 2025
Isolation, Propagation, and Identification of Bacterial Species with Hydrocarbon Metabolizing Properties from Aquatic Habitats
Published on: December 7, 2021
Isolation, characterization and optimization of chrysene degradation using bacteria isolated from oil-contaminated
Smeera Thomas1, Nitha Thalakkale Veettil2, Kavitha Subbiah3
1Department of Biotechnology, Karunya Institute of Technology and Sciences (Deemed-to-be University), Karunya Nagar, Coimbatore 641114, Tamil Nadu, India E-mail: kavibiotec@karunya.edu; Department of Biotechnology, Sahrdaya College of Engineering and Technology, Kodakara, Thrissur 680684, Kerala, India.
Abstract:
Polyaromatic hydrocarbons (PAHs) are uncharged, non-polar molecules generated from natural and anthropogenic activities, where the emissions from anthropogenic activities predominate. Chrysene is a high molecular weight PAH, which is found to be highly recalcitrant and mutagenic in nature. The aim of this study was to isolate chrysene-degrading microorganisms from oil-contaminated water and to enhance their degradative conditions using design expert. From the various samples collected, 19 bacterial strains were obtained through enrichment culture and the one which showed highest activity was identified by 16S rRNA sequencing as Bacillus halotolerans. Under optimum conditions of 100 mg/L chrysene concentration, 1,000 mg/L nitrogen source, and pH 6, B. halotolerans exhibited 90% chrysene degradation on sixth day. Positive results for the enzymes laccase and catechol 1,2 dioxygenase confirmed the ability for chrysene degradation by the isolated strain. Major metabolic intermediate determined in gas chromatography-mass spectrometry (GCMS) analysis was diisooctyl phthalate. Hence it can be concluded that B. halotolerans can be a promising candidate for the removal of high molecular weight (HMW) hydrocarbons from contaminated environments.
