Global Centre for Environmental Remediation (GCER), College of Engineering, Science and Environment, The University of Newcastle, ATC Building, University Drive, Callaghan, NSW, 2308, Australia.
Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), The University of Newcastle, ATC Building, Callaghan, NSW, 2308, Australia.
Biodegradation. 2022 Dec;33(6):575-591. doi: 10.1007/s10532-022-09996-9. Epub 2022 Aug 17.
Bioaugmentation effectively enhances microbial bioremediation of hazardous polycyclic aromatic hydrocarbons (PAHs) from contaminated environments. While screening for pyrene-degrading bacteria from a former manufactured gas plant soil (MGPS), the mixed enrichment culture was found to be more efficient in PAHs biodegradation than the culturable pure strains. Interestingly, analysis of 16S rRNA sequences revealed that the culture was dominated by a previously uncultured member of the family Rhizobiaceae. The culture utilized C1 and other methylotrophic substrates, including dimethylformamide (DMF), which was used as a solvent for supplementing the culture medium with PAHs. In the liquid medium, the culture rapidly degraded phenanthrene, pyrene, and the carcinogenic benzo(a)pyrene (BaP), when provided as the sole carbon source or with DMF as a co-substrate. The efficiency of the culture in the bioremediation of PAHs from the MGPS and a laboratory waste soil (LWS) was evaluated in bench-scale slurry systems. After 28 days, 80% of Σ16 PAHs were efficiently removed from the inoculated MGPS. Notably, the bioaugmentation achieved 90% removal of four-ringed and 60% of highly recalcitrant five- and six-ringed PAHs from the MGPS. Likewise, almost all phenanthrene, pyrene, and 65% BaP were removed from the bioaugmented LWS. This study highlights the application of the methylotrophic enrichment culture dominated by an uncultured bacterium for the efficient bioremediation of PAHs.
生物强化有效地增强了微生物对污染环境中危险多环芳烃（PAHs）的生物修复。在从前的人造煤气厂土壤（MGPS）中筛选芘降解细菌时，发现混合富集培养物在 PAHs 生物降解方面比可培养的纯菌株更有效。有趣的是，16S rRNA 序列分析表明，该培养物主要由以前未培养的根瘤菌科成员组成。该培养物利用 C1 和其他甲基营养型底物，包括二甲基甲酰胺（DMF），DMF 被用作补充培养基中 PAHs 的溶剂。在液体培养基中，当作为唯一碳源或与 DMF 作为共底物时，该培养物能够快速降解菲、芘和致癌的苯并(a)芘（BaP）。在中试规模的浆态系统中评估了该培养物在 MGPS 和实验室废物土壤（LWS）中修复 PAHs 的效率。28 天后，接种的 MGPS 中 80%的Σ16 PAHs 被有效地去除。值得注意的是，生物强化从 MGPS 中去除了 90%的四环和 60%的高度难降解的五环和六环 PAHs。同样，从生物强化的 LWS 中去除了几乎所有的菲、芘和 65%的 BaP。本研究强调了以未培养细菌为主导的甲基营养富集培养物在 PAHs 高效生物修复中的应用。
