根系分泌物-烷基酚共代谢作用下芦苇根际细菌与真菌的群落结构变化及环境限定因子  

Community structure variation of bacteria and fungi in the Phragmites australis rhizosphere and their environmental limiting factors by the co-metabolism between root exudates and alkylphenols

作　　者：阿丹 姜钰 洪志锋 张旎晨 杨杰文 林庆祺 倪卓彪 晁元卿 A Dan;JIANG Yu;HONG Zhifeng;ZHANG Nichen;YANG Jiewen;LIN Qingqi;NI Zhuobiao;CHAOYuanqing(Engineering and Technology Research Center for Agricultural Land Pollution Integrated Prevention and Control of Guangdong Higher Education Institutes,College of Resources and Environment,Zhongkai University of Agriculture and Engineering,Guangzhou 510225;Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology,School of Environmental Science and Engineering,Sun Yat-sen University,Guangzhou 510006;Guangdong Laboratory for Lingnan Modern Agriculture,Guangzhou 510642;Guangdong Provincial Key Laboratory of Agricultural&Rural Pollution Abatement and Environmental Safety,College of Natural Resources and Environment,South China Agricultural University,Guangzhou 510642)

机构地区：[1]仲恺农业工程学院资源与环境学院,广东省普通高校农业产地污染综合防治工程技术研究中心,广州510225 [2]中山大学环境科学与工程学院,广东省环境污染控制与修复技术重点实验室,广州510006 [3]岭南现代农业科学与技术广东省实验室,广州510642 [4]华南农业大学资源环境学院,广东省农业农村污染治理与环境安全实验室,广州510642

出　　处：《环境科学学报》2023年第11期362-371,共10页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金-青年项目(No.41907293);广东省自然科学基金-面上项目(No.2022A1515011319);广州市科技计划项目(No.202201011783,202102020945)。

摘　　要：已知芳香族根系有机酸可通过共代谢作用有效促进烷基酚等有机污染物在湿地植物根际的生物降解,为进一步探明其共代谢机理与微生物响应间的映射关系,分别选取对香豆酸为代表性芳香族根系有机酸(特异性共代谢底物)、草酸为代表性小分子根系有机酸(非特异性共代谢底物),以对叔丁基苯酚(PTBP)为典型烷基酚,以常见湿地植物芦苇(Phragmites australis)为受试植物展开土培实验,结合高通量测序和生物信息学分析,探究共代谢作用下芦苇根际细菌和真菌的群落结构变化规律及环境限定因子.结果表明,PTBP在不同处理下的去除率达到88%~98%,虽然不同根系有机酸参与下PTBP的去除效果相差不大,但其去除途径各不相同.一方面,草酸的添加有利于通过释放生长激素促进根系发育的茎点霉属(Phoma)富集,从而提高植物的生物增长量及其PTBP的植物吸收量,尽管草酸能够促进土著微生物生长,但不能特异性富集PTBP降解菌.另一方面,虽然对香豆酸的化感作用抑制了PTBP的植物吸收,但其存在促进了鞘氨醇单胞菌属(Sphingomonas)、芽单胞菌属(Gemmatimonas)和镰刀菌属(Fusarium)等具有PTBP降解潜能的菌群富集,从而强化了PTBP的共代谢降解.可见,芳香族根系有机酸和小分子有机酸分别通过强化功能菌活性和促进植物生长影响PTBP的生物降解和植物吸收途径.所选环境限定因子对细菌和真菌群落的总解释量达到60%~62%,特别是pH同时对细菌群落和真菌群落均具有极显著的相关性.对香豆酸、草酸等根系有机酸可以迅速降低土壤pH,而土壤pH的改变可以通过调节微生物群落装配过程直接对微生物群落结构产生影响,也可以通过改变土壤因子有效态间接影响微生物群落组成.Aromatic root organic acids have been known to effectively promote the biodegradation of organic pollutants such as alkylphenols in the rhizosphere of wetland plants by co-metabolism.To further explore the mapping relationship between the co-metabolism mechanism and the microbial response,p-coumaric acid and oxalic acid were selected as the representative root organic acid of aromatic compound(specific co-metabolite substrates)and root organic acids of small molecules(non-specific co-metabolite substrates),respectively;meanwhile,p-tert-butylphenol(PTBP)was used as the typical alkylphenol,and Phragmites australis as thecommon wetland plant in this study.The community structure change and environmental limiting factor of rhizosphere bacteria and fungi by co-metabolism were investigated by using high-throughput sequencing and bioinformatics analysis.The results showed that the removal efficiencies of PTBP were 88%~98%in different treatments.Although there is no significant difference of the PTBP removal by different root organic acids,their removal pathways are different.For the one hand,the addition of oxalic acid may promote Phoma,which can release growth hormone for plant development and therefore increase the total absorption of PTBP in root biomass.Oxalic acid may also enrich the indigenous microorganisms,but it cannot specifically enrich the PTBP-degrading bacteria.For the other hand,pcoumaric acid inhibited the plant absorption of PTBP via allelopathic effect,but promoted the growth of potential PTBP-degrading bacteria such as Sphingomonas,Gemmatimonas and Fusarium,thus enhancing the co-metabolic degradation of PTBP.Hence,aromatic root organic acids and small molecular organic acids may affect the PTBP removal by promoting the microbial activity and the plant growth,respectively.The total explanatory amount of the selected environmental limiting factors reached 60%~62%for bacterial and fungal communities,especially the pH values.Organic acids(i.e.,p-coumaric acid and oxalic acid)can rapidly reduce the soil pH

关 键 词：根系有机酸 烷基酚 共代谢作用 微生物群落结构 环境限定因子 

分 类 号：X172[环境科学与工程—环境科学]