Biodegradation performance and diversity of enriched bacterial consortia capable of degrading high-molecular-weight polycyclic aromatic hydrocarbons

ABSTRACT

Polycyclic aromatic hydrocarbons (PAHs) are key organic pollutants in the environment that pose threats to the ecosystem and human health. The degradation of high molecular weight (HMW) PAHs by enriched bacterial consortia has been previously studied, while the involved metabolisms and microbial communities are still unclear and warrant further investigations. In this study, five bacterial consortia capable of utilizing different PAHs (naphthalene, anthracene, and pyrene) as the sole carbon and energy sources were enriched from PAH-contaminated soil samples. Among the five consortia, consortium TC exhibited the highest pyrene degradation efficiency (91%) after 19 d of incubation. The degradation efficiency was further enhanced up to 99% by supplementing yeast extract. Besides, consortium TC showed tolerances to high concentrations of pyrene (up to 1000 mg/L) and different heavy metal stresses (including Zn²⁺, Cd²⁺, and Pb²⁺). The dominant genus in consortium TC, GS, and PL showing relatively higher degradation efficiency for anthracene and pyrene was Pseudomonas, whereas consortium PG and GD were predominated by genus Achromobacter and class Enterobacteriaceae, respectively. Consortium TC, as a highly efficient HMW PAH-degrading consortium, could be applied for synergistic biodegradation of HMW PAHs and in situ bioremediation of the sites contaminated with both PAHs and heavy metals.

GRAPHICAL ABSTRACT

KEYWORDS:

• Biodegradation
• heavy metal
• high molecular weight
• microbial community structure
• polycyclic aromatic hydrocarbon

Acknowledgments

The project was supported by the National Natural Science Foundation of China (No. 52070156, 31600421 and 51909210), Natural Science Basic Research Plan in Shaanxi Province of China (No. 2020JM-460 and 2019JQ-752), China Postdoctoral Science Foundation (No. 2014M562439), Shaanxi Postdoctoral Science Foundation, Scientific Research Program Funded by Shaanxi Provincial Education Department (No. 17JS097), and Visiting Researcher Fund Program of the State Key Laboratory of Eco-hydraulics in Northwest Arid Region, Xi’an University of Technology (No. 2016KFKT-2). The laboratory analysis efforts of Chan Li, Xiaohua Lin, and Fangzhao Zhou are greatly appreciated. Prof. Jidong Liang at Xi’an Jiaotong University is also gratefully acknowledged for her constructive suggestions.

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article and its supplementary materials.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by China Postdoctoral Science Foundation [grant number 2014M562439]; National Natural Science Foundation of China [grant number 31600421, 52070156]; Shaanxi Province Postdoctoral Science Foundation; Visiting Researcher Fund Program of the State Key Laboratory of Eco-hydraulics in Northwest Arid Region, Xi’an University of Technology [grant number 2016KFKT-2]; Scientific Research Program Funded by Shaanxi Provincial Education Department [grant number 17JS097]; Natural Science Basic Research Plan in Shaanxi Province of China [grant number 2019JQ-752,2020JM-460].