Biodegradable dissolved organic carbon shapes bacterial community structures and co-occurrence patterns in large eutrophic Lake Taihu

• 作者: Lei Zhou Yongqiang Zhou Xiangming Tang Yunlin Zhang Erik Jeppesen
• 来源期刊: 环境科学学报（英文版）
• 年，卷（期）: 2021,（9）
• 所属期刊栏目: Regular articles
• 页码范围: 205-217
• 页数: 13页
• 语种: 英文

摘要

Interactions between dissolved organic matter (DOM) and bacteria are central in the biogeo-chemical cycles of aquatic ecosystems;however, the relative importance of biodegradable dissolved organic carbon (BDOC) compared with other environmental variables in struc-turing the bacterial communities needs further investigation. Here, we investigated bac-terial communities, chromophoric DOM (CDOM) characteristics and physico-chemical pa-rameters as well as examined BDOC via bioassay incubations in large eutrophic Lake Taihu, China, to explore the importance of BDOC for shaping bacterial community structures and co-occurrence patterns. We found that the proportion of BDOC (％BDOC) correlated significantly and positively with the DOC concentration and the index of the contribution of recent produced autochthonous CDOM (BIX).％BDOC, further correlated positively with the rela-tive abundance of the tryptophan-like component and negatively with CDOM aromaticity, indicating that autochthonous production of protein-like CDOM was an important source of BDOC. The richness of the bacterial communities correlated negatively with ％BDOC, in-dicating an enhanced number of species in the refractory DOC environments.％BDOC was identified as a significant stronger factor than DOC in shaping bacterial community com-position and the co-occurrence network, suggesting that substrate biodegradability is more significant than DOC quantity determining the bacterial communities in a eutrophic lake. Environmental factors explained a larger proportion of the variation in the conditionally rare and abundant subcommunity than for the abundant and the rare bacterial subcommu-nities. Our findings emphasize the importance of considering bacteria with different abundance patterns and DOC biodegradability when studying the interactions between DOM and bacteria in eutrophic lakes.