Liu Lemian, Wang Shanshan, Chen Jianfeng
Technical Innovation Service Platform for High Value and High Quality Utilization of Marine Organism, Fuzhou University, Fuzhou, 350108, China.
Fujian Engineering and Technology Research Center for Comprehensive Utilization of Marine Products Waste, Fuzhou University, Fuzhou, 350108, China.
Environ Microbiol. 2021 Nov;23(11):6663-6675. doi: 10.1111/1462-2920.15702. Epub 2021 Aug 10.
Functional redundancy is considered common in microbial systems, but recent studies have challenged this idea. The mechanism for this contradictory result is not clear. However, in this study, we hypothesize that strong environmental filtering which links to the anthropogenic activities is able to weaken microbial functional redundancy. We used metagenome and 16S rRNA gene high-throughput sequencing to investigate planktonic microbial communities in a subtropical river. We found that the weak anthropogenic activities might result in a low selection pressure in the river upstream area. Therefore, the microbial community functional attributes were stable although the community composition changed with the water temperature and NO -N in upstream area (this indicates functional redundancy). However, the strong anthropogenic activities in river downstream area selected pollutant-degraded functions (e.g. nitrogen metabolism, toluene, xylenes and ethylbenzene degradation) and potentially pollutant-degraded (tolerant) microbes, and therefore caused the microbial community composition synchronously changed with the variation of community functional attributes. Our results reveal that strong environmental filtering which associates with the anthropogenic activities not only has effects on microbial community composition and community functional attributes but also on their relationships. These results provide a new insight to refine the functional redundancy idea.
功能冗余在微生物系统中被认为是普遍存在的，但最近的研究对这一观点提出了挑战。这种矛盾结果的机制尚不清楚。然而，在本研究中，我们假设与人为活动相关的强烈环境过滤能够削弱微生物功能冗余。我们使用宏基因组和16S rRNA基因高通量测序来研究一条亚热带河流中的浮游微生物群落。我们发现，较弱的人为活动可能导致河流上游区域的选择压力较低。因此，尽管上游区域的群落组成随水温及硝态氮变化（这表明存在功能冗余），但微生物群落的功能属性是稳定的。然而，河流下游区域强烈的人为活动选择了污染物降解功能（如氮代谢、甲苯、二甲苯和乙苯降解）以及潜在的污染物降解（耐受）微生物，因此导致微生物群落组成随群落功能属性的变化而同步改变。我们的结果表明，与人为活动相关的强烈环境过滤不仅影响微生物群落组成和群落功能属性，还影响它们之间的关系。这些结果为完善功能冗余观点提供了新的见解。
