Tween-80 enhanced biodegradation of naphthalene by Klebsiella quasipneumoniae

• Published in: Antonie van Leeuwenhoek 2023-07, Vol.116 (7), p.697-709
• Main Authors: Olukanni, Olumide D., Albert, Anthony A., Farinto, Micheal, Awotula, Ayodeji O., Osuntoki, Akinniyi A.
• Format: Article
• Language: English
• Subjects: Aquatic organisms; Aromatic compounds; Bacteria - genetics; Biodegradation; Biodegradation, Environmental; Biomedical and Life Sciences; Chromatography; Dihydroxybenzoic acid; Fourier transforms; Gas chromatography; High performance liquid chromatography; Hydrocarbons; Hydrocarbons - metabolism; Industrial areas; Klebsiella; Life Sciences; Liquid chromatography; Medical Microbiology; Metabolites; Microbiology; Naphthalene; Naphthalenes - metabolism; Oil pollution; Original Paper; Petroleum hydrocarbons; Petroleum products; Plant Sciences; Polycyclic aromatic hydrocarbons; Polycyclic Aromatic Hydrocarbons - metabolism; Polysorbates - metabolism; RNA, Ribosomal, 16S - genetics; RNA, Ribosomal, 16S - metabolism; rRNA 16S; Soil bacteria; Soil contamination; Soil pollution; Soil Science & Conservation; Surface-Active Agents - metabolism; Surfactants; Tyrosinase
• ISSN: 0003-6072; 1572-9699
• DOI: 10.1007/s10482-023-01839-8

Accidental spillage of petroleum products and industrial activities result in various hydrocarbons in the environment. While the n-hydrocarbons are readily degraded, the polycyclic aromatic hydrocarbons (PAHs) are recalcitrant to natural degradation, toxic to aquatic life and are responsible for diverse health challenges in terrestrial animals; suggesting the need for faster and more eco-friendly ways of removing PAHs from the environment. In this study, the surfactant tween-80 was used to enhance a bacterium's intrinsic naphthalene biodegradation activity. Eight bacteria isolated from oil-contaminated soils were characterised using morphological and biochemical methods. The most effective strain was identified as Klebsiella quasipneumoniae using 16S rRNA gene analysis. High-Performance Liquid Chromatography (HPLC) analyses showed that the detectable concentration of naphthalene was decreased from 500 to 157.18 μg/mL (67.4%) after 7 d in the absence of tween-80, while 99.4% removal was achieved in 3 d in the presence of tween-80 at 60 μg/mL concentration. The peaks observed in the Fourier Transform Infra-Red Spectroscopy (FTIR) spectrum of control (naphthalene), which were absent in that of the metabolites, further established naphthalene degradation. Furthermore, Gas Chromatography-Mass Spectrometer (GCMS) revealed metabolites of single aromatic ring, such as 3,4-dihydroxybenzoic acid 4-hydroxylmethylphenol, which confirmed that the removal of naphthalene is by biodegradation. Tyrosinase induction and laccase activities suggested the involvement of these enzymes in naphthalene biodegradation by the bacterium. Conclusively, a strain of K. quasipneumoniae that can effectively remove naphthalene from contaminated environments has been isolated, and its biodegradation rate was doubled in the presence of non-ionic surfactant, tween-80.