1.Guilin University of Technology;2.Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Nanning Normal University
the ‘One Hundred Talents’ Project of Guangxi (grant no. 6020303891251); the National Natural Science Foundation of China no. 41966005, U20A2087
海洋浮游细菌在生物地球化学循环过程中具有不可替代的作用。为解析广西北部湾茅尾海夏冬季浮游细菌群落结构及其关键环境影响因子，于2017年6月(夏季)和2017年12月(冬季)在该海域设置7个站点，采集0.5m处表层海水样品，利用16S核糖体RNA (16S rRNA)基因高通量测序技术，分析茅尾海浮游细菌群落结构与多样性。结果表明：茅尾海海域浮游细菌隶属于11个门、36个纲、86个目、188个科和506个属；主要浮游细菌类群为变形菌门(Proteobacteria, 52.47%)、厚壁菌门(Firmicutes, 17.34%)、放线菌门(Actinobacteria, 16.39%)、拟杆菌门(Bacteroidetes, 7.54%)和蓝细菌门(Cyanobacteria, 5.38%)，共占浮游细菌总丰度的99.12%。北部湾茅尾海夏季浮游细菌群落Chao 1指数和Richness指数均显著(P<0.05)高于冬季。主坐标分析(PCoA)和相似性分析(ANOSIM)结果表明，不同季节浮游细菌群落结构存在极显著差异(R=0.586, P<0.001)。在目分类水平上进行组间差异分析(Welch’s t-test)，具有季节性丰度显著差异的类群共有15个(P<0.05)，其中尤泽比氏菌目(Euzebyales)、红杆菌目(Rhodobacterales)、马尾藻海演化枝11(SAR11)、黄杆菌目(Flavobacteriales)、乳杆菌目(Lactobacillales)、芽孢杆菌目(Bacillales)、假单胞菌目(Pseudomonadales) 在夏季样品中显著增高；海洋螺菌目(Oceanospirillales)、丙酸杆菌目(Propionibacteriales)、涅瓦菌目(Nevskiales)、弧菌目(Vibrionales)、伯克氏菌目(Burkholderiales)、分枝杆菌目(Mycobacteriales)、红螺菌目(Rhodospirillales)、亚硝化单胞菌目(Nitrosomonadales)在冬季样品中显著增高。夏季浮游细菌属的共发生网络表现出更复杂的网络拓扑结构。物种间的相互作用主要以正相关为主，且夏季(70.3%)高于冬季(68.9%)。Partial Mantel检验相关分析表明，浮游细菌群落与温度、盐度、溶解氧、总溶解氮和总溶解磷呈显著正相关(P<0.05)。其中，温度(R=0.326, P<0.001)和总溶解磷(R=0.512, P<0.001)与群落结构的相关程度较高，是显著影响浮游细菌群落结构的关键环境因子。综上，本研究成果，为进一步揭示北部湾海洋浮游细菌多样性，以及为茅尾海海域生态修复与资源利用提供科学参考依据。
Planktonic bacteria play a key role in biogeochemical cycling in marine environment. To investigate the community structure of planktonic bacteria across summer and winter and their key environmental drivers, the surface seawater samples at 0.5m depth from seven stations were collected in June and December, 2017, respectivly, in the Maowei Sea, Beibu Gulf, Guangxi. We then analyzed the community structure and diversity of planktonic bacteria using 16S rRNA gene high-throughput sequencing. Our results showed that the planktonic bacteria community in the Maowei Sea belonged to 11 phyla, 36 classes, 86 orders, 188 families, and 506 genera. Proteobacteria (52.47%), Firmicutes (17.34%), Actinobacteria (16.39%), Bacteroidetes (7.54%), and Cyanobacteria (5.38%) were the major phyla, which accounting for 99.12% of the total abundance of the planktonic bacteria. The Chao 1 Index and Richness Index of the planktonic bacterial community in summer samples were significantly higher than that in winter in the Maowei Sea of Beibu Gulf (P<0.05). Additionally, the results of PCoA analysis based on Bray-Curtis distance and ANOSIM (R=0.586, P<0.001) indicated that there were significant differences in the planktonic bacterial community structure between the two seasonal groups. The Welch’s t-test indicated that the abundance of 15 orders significantly varied between summer and winter (P<0.05). Among them, Euzebyales, Rhodobacterales, SAR11, Flavobacteriales, Lactobacillales, Bacillales, and Pseudomonadales were significantly increased in summer group, Oceanospirillales, Propionibacteriales, Nevskiales, Vibrionales, Burkholderiales, Mycobacteriales, Rhodospirillales, and Nitrosomonadales were significantly increased in winter group. The co-occurrence network analysis based on SparCC indicated that a more complex topological feature of the bacterial co-occurrence network was found in summer than that in winter. Furthermore, the inter-species interactions of the co-occurrence network were mainly positive relationships, which were greater in summer than that in winter. And the proportion of positive correlation inter-species is 70.3% in summer group, and that is 68.9% in winter group. The partial Mantel test demonstrated that the planktonic bacterial community was significantly positively (P<0.05) correlated with temperature, salinity, dissolved oxygen, total dissolved nitrogen, and total dissolved phosphorus. Among these factors, temperature (R=0.326, P<0.001) and total dissolved phosphorus (R=0.512, P<0.001) with the highest correlation degree with the community structure of the planktonic bacteria in the Maowei Sea, Beibu Gulf, which were identified as the key factors that affecting the community structure of planktonic bacteria. Overall, this work provides a scientific basis for revealing marine planktonic bacteria diversity in Beibu Gulf, as well as solid evidences for ecological restoration and resource utilization in the Maowei Sea.
廖能健,赵华显,杨恕,李晓丽,黄炯清,覃欣怡,姜宫凌侠,黄亮亮,李楠.广西北部湾茅尾海夏冬季浮游细菌群落结构及其影响因子.生态学报,,(). http://dx. doi. org/10.5846/stxb202208032206复制