Anaerobic biodegradation of benzo(a)pyrene by a novel Cellulosimicrobium cellulans CWS2 isolated from polycyclic aromatic hydrocarbon-contaminated soil

Abstract

Cellulosimicrobium cellulans CWS2, a novel strain capable of utilizing benzo(a)pyrene (BaP) as the sole carbon and energy source under nitrate-reducing conditions, was isolated from PAH-contaminated soil. Temperature and pH significantly affected BaP biodegradation, and the strain exhibited enhanced biodegradation ability at temperatures above 30 °C and between pH 7 and 10. The highest BaP removal rate (78.8%) was observed in 13 days when the initial BaP concentration was 10 mg/L, and the strain degraded BaP at constant rate even at a higher concentration (50 mg/L). Metal exposure experimental results illustrated that Cd(II) was the only metal ion that significantly inhibited biodegradation of BaP. The addition of 0.5 and 1.0 g/L glucose enhanced BaP biodegradation, while the addition of low-molecular-weight organic acids with stronger acidity reduced BaP removal rates during co-metabolic biodegradation. The addition of phenanthrene and pyrene, which were degraded to some extent by the strain, showed no distinct effect on BaP biodegradation. Gas chromatography–mass spectrometry (GC-MS) analysis revealed that the five rings of BaP opened, producing compounds with one to four rings which were more bioavailable. Thus, the strain exhibited strong BaP degradation capability and has great potential in the remediation of BaP-/PAH-contaminated environments.

Bacterial Diversity and the Geochemical Landscape in the Southwestern Gulf of Mexico

“…Interestingly, most of the phylotypes detected as differentially abundant in the shallow group are related to hydrocarbon degradation, such as Microcoleus ( Sánchez et al, 2005 ), Ahrensia ( Gontikaki et al, 2018 ), and Thermococcus ( Mardanov et al, 2009 ), and more specific genera such as Tropicimonas ( Harwati et al, 2009 ), Dethiosulfatibacter ( Muangchinda et al, 2013 ), Cellulosimicrobium ( Qin et al, 2018 ), Roseobacter ( Liu et al, 2016 ), Prolixibacter ( Li et al, 2012 ), Desulfuromusa ( Ramos et al, 2013 ), Oceanicola ( Hassanshahian and Boroujeni, 2016 ), and Salinivibrio ( Selvarajan et al, 2017 ) are involved in aromatic hydrocarbons degradation, supporting our hypothesis that this abiotic factor modulates the bacterial communities in the shallow region. We also found other genera such as Psychrilyobacter , which participates in the anaerobic degradation of organic matter ( Graue et al, 2012 ), and Dehalococcoides ( Nuzzo et al, 2017 ) and Dehalobacterium ( Yimiti et al, 2011 ), which detoxify anoxic contamination in marine sediments, such as polychlorinated biphenyls.…”

Current Status of and Future Perspectives in Bacterial Degradation of Benzo[a]pyrene

“…This strain degraded up to 80% of 10 mg·L −1 of BaP in the presence of 1.0 g·L −1 of nitrate. The addition of glucose led to an improved degradation efficiency of BaP, unlike the addition of organic acids, such as tartaric acid, which reduced degradation efficiency [ 52 ].…”

Current Status of the Degradation of Aliphatic and Aromatic Petroleum Hydrocarbons by Thermophilic Microbes and Future Perspectives

“…However, as has been shown in mesophilic conditions, the use of growth-promoting substrates can inhibit the degradation of the non-growth substrate [88,89]. For instance, in mesophilic conditions, one study showed that the use of glucose (as growth-promoting substrate) inhibited the expression of enzymes involved in PAH biodegradation [89].…”