Potential natural attenuation of petroleum hydrocarbons in fuel contaminated soils: Focusing on anaerobic fuel biodegradation involving microbial Fe(III) reduction

• Published in: Chemosphere Vol. 341; p. 140134
• Main Authors: Kang, Myeong-Jung, Kim, Han-Suk, Zhang, Yidan, Park, Kanghyun, Jo, Ho Young, Finneran, Kevin T., Kwon, Man Jae
• Format: Journal Article
• Language: English; Japanese
• Published: Elsevier Ltd 01.11.2023; Elsevier BV
• Subjects: Anaerobiosis; biodegradation; Biodegradation, Environmental; Chlamydiae; Fe(III)-Reducing bacteria; fermentation; Fermenting bacteria; Ferric Compounds; Ferrous Compounds; Geobacter; Hydrocarbons; liquids; Microbial community; military lands; oxygen; Petroleum; Soil; solubility; species diversity; toxicity; TPH biodegradation; Zoogloea; Fermenting bacteria; TPH biodegradation; Fe(III)-Reducing bacteria; Microbial community
• ISSN: 0045-6535; 1879-1298; 1879-1298
• DOI: 10.1016/j.chemosphere.2023.140134

Liquid fossil fuels, collectively known as total petroleum hydrocarbons (TPHs), are highly toxic and frequently leak into subsurface environments due to anthropogenic activities. As an in-situ biological remedial option for TPH contamination, aerobic TPH biodegradation is limited due to oxygen's low solubility in water, and because it is consumed quickly by aerobic bacteria. Thus, we investigated the potential of anaerobic TPH degradation by indigenous fermenting bacteria and Fe(III)-reducing bacteria. Twenty 6–10 m soil cores were collected from a closed military base subject to ongoing TPH contamination since the 1980s. Physicochemical and microbial properties were determined at 0.5-m intervals in each core. To assess the relationship between TPH degradation and microbial Fe(III) reduction, soil samples were grouped into high-TPH (>500 mg kg−1) and high-Fe(II) (>450 mg kg−1), high-TPH and low-Fe(II), low-TPH and high-Fe(II), and low-TPH and low-Fe(II) groups. Alpha diversity was significantly lower in high-TPH groups than in low-TPH groups, suggesting that high TPH concentrations exerted a strong selective pressure on bacterial communities. In the high-TPH and low-Fe(II) group, fermenting bacteria, including Microgenomatia and Chlamydiae, were more abundant, suggesting that TPH biodegradation occurred via fermentation. In the high-TPH and high-Fe(II) group, Fe(III)-reducing bacteria, including Geobacter and Zoogloea, were more abundant, suggesting that microbial Fe(III) reduction enhances TPH biodegradation. In contrast, the fermenting and/or Fe(III)-reducing bacteria were not statistically abundant in the low-TPH groups. [Display omitted] •Field soil samples from a site contaminated with TPH for >30 yrs were examined•Positive correlations of TPH both with Fe(II) and bacterial numbers were observed•Fermenters and Fe(III)-reducers were presented more in the presence of high TPH and Fe(II)•Anaerobic TPH biodegradation involving Fe(III) reduction may occur widely due to Fe(III) ubiquity at contaminated sites