| Autor: |
Faheem M; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.; University of Chinese Academy of Sciences, Beijing 100049, China., Shabbir S; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210008, China., Zhao J; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China., G Kerr P; School of biomedical Science, Charles Sturt University, Wagga Wagga, NSW 2678, Australia., Ali S; Department of Environmental Sciences and Engineering, Government College University, Faisalabad 38000, Pakistan.; Department of Biological Sciences and Technology, China Medical University, Taichung 40402, Taiwan., Sultana N; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.; University of Chinese Academy of Sciences, Beijing 100049, China.; Department of Agroforestry and Environmental Science, Sher-e-Bangla Agricultural University (SAU), Sher-e-Bangla nagar, Dhaka 1207, Bangladesh., Jia Z; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China. |
| Abstrakt: |
Priority pollutants such as polyethylene (PE) microplastic, lead (Pb 2+ ), and cadmium (Cd 2+ ) have attracted the interest of environmentalists due to their ubiquitous nature and toxicity to all forms of life. In this study, periphytic biofilms (epiphyton and epixylon) were used to bioremediate heavy metals (HMs) and to biodegrade PE under high (120,000 ppm) methane (CH 4 ) doses. Both periphytic biofilms were actively involved in methane oxidation, HMs accumulation and PE degradation. Epiphyton and epixylon both completely removed Pb 2+ and Cd 2+ at concentrations of 2 mg L -1 and 50 mg L -1 , respectively, but only partially removed these HMs at a relatively higher concentration (100 mg L -1 ). Treatment containing 12% 13 CH 4 proved to be most effective for biodegradation of PE. A synergistic effect of HMs and PE drastically changed microbial biota and methanotrophic communities. High-throughput 16S rRNA gene sequencing revealed that Cyanobacteria was the most abundant class, followed by Gammaproteobacteria and Alphaproteobacteria in all high-methane-dose treatments. DNA stable-isotope probing was used to label 13 C in a methanotrophic community. A biomarker for methane-oxidizing bacteria, pmoA gene sequence of a 13 C-labeled fraction, revealed that Methylobacter was most abundant in all high-methane-dose treatments compared to near atmospheric methane (NAM) treatment, followed by Methylococcus . Methylomonas , Methylocystis , Methylosinus, and Methylocella were also found to be increased by high doses of methane compared to NAM treatment. Overall, Cd +2 had a more determinantal effect on methanotrophic activity than Pb 2+ . Epiphyton proved to be more effective than epixylon in HMs removal and PE biodegradation. The findings proved that both epiphyton and epixylon can be used to bioremediate HMs and biodegrade PE as an efficient ecofriendly technique under high methane concentrations. |
