Indigenous Kurthia sp. degrading phenol isolated from a petrochemical dumpsite and its derivatives identified by gas chromatography-mass spectrometry

Abstract

Phenol is a toxic aromatic compound widely released into the environment through oil refineries, petrochemical industries, and industrial effluents, posing serious risks to ecosystems and human health. Given its persistence and toxicity even at low concentrations, environmentally sustainable methods for its removal are highly sought. Biological remediation using indigenous microorganisms offers a cost-effective and eco-friendly substitute to conventional physicochemical methods. In the present study, aerobic phenol-tolerant bacterial isolates were obtained from petrochemical dumpsite soil and characterised for their capacity to grow in MSM supplemented with phenol. The isolate was identified as Kurthia populi GB1 based on morphological, biochemical, and 16S rRNA gene sequence analysis. The phenol tolerance of the isolate was assessed at various concentrations, while the influence of pH and temperature on growth was investigated under aerobic conditions, and phenol transformation products were tentatively identified using gas chromatography-mass spectrometry. The isolate demonstrated a tolerance to phenol concentrations reaching 500 mg/l, with optimal growth conditions identified at a pH of 6 and temperatures of 25 - 37°C. GC-MS analysis revealed the existence of various low-molecular-weight compounds, indicating potential phenol transformation activity; however, conclusive degradation pathways need to be determined. The results emphasise the promise of indigenous bacteria in phenol bioremediation efforts.