Strong seasonal differences of bacterial polysaccharide utilization in the North Sea over an annual cycle
Strong seasonal differences of bacterial polysaccharide utilization in the North Sea over an annual cycle
复制标题
DOI：
10.1111/1462-2920.15997
复制
发表时间：
2022-04-17
影响因子：
5.1
通讯作者：
Fuchs, Bernhard M.
中科院分区：
文献类型：
--
作者：
Giljan, Greta;Arnosti, Carol;Fuchs, Bernhard M.
海洋异养细菌对全球碳循环的贡献很大，部分是通过利用植物源多糖。两种不同的多糖利用模式-胞外水解和自私的摄取-的模式和速率，以前已经发现在春季浮游植物水华事件的变化。在这里，我们调查了细菌利用海带多糖，木聚糖和硫酸软骨素的季节性变化。强烈的季节性差异是明显的多糖利用的模式和速度，以及在细菌群落组成。与冬季的2月相比，在5月的春季开花期间，在孵育中检测到多糖利用，并且所有细菌的较高部分自私地摄取海带多糖。最高的多糖利用率测定在6月和9月，介导的细菌群落，显着不同的春季组合。广泛的自私海带多糖摄取，例如，在6月的几个小时内检测到，而软骨素的胞外水解是占主导地位的9月。除了众所周知的拟杆菌门和γ-变形菌门分支，数量较少的疣状微生物分支Pedosphaeraceae可以被确定为快速海带多糖利用者。总之，多糖的利用证明是高度可变的季节，无论是在模式和速度，也由所涉及的细菌分支。
Marine heterotrophic bacteria contribute considerably to global carbon cycling, in part by utilizing phytoplankton-derived polysaccharides. The patterns and rates of two different polysaccharide utilization modes - extracellular hydrolysis and selfish uptake - have previously been found to change during spring phytoplankton bloom events. Here we investigated seasonal changes in bacterial utilization of three polysaccharides, laminarin, xylan and chondroitin sulfate. Strong seasonal differences were apparent in mode and speed of polysaccharide utilization, as well as in bacterial community compositions. Compared to the winter month of February, during the spring bloom in May, polysaccharide utilization was detected earlier in the incubations and a higher portion of all bacteria took up laminarin selfishly. Highest polysaccharide utilization was measured in June and September, mediated by bacterial communities that were significantly different from spring assemblages. Extensive selfish laminarin uptake, for example, was detectible within a few hours in June, while extracellular hydrolysis of chondroitin was dominant in September. In addition to the well-known Bacteroidota and Gammaproteobacteria clades, the numerically minor verrucomicrobial clade Pedosphaeraceae could be identified as a rapid laminarin utilizer. In summary, polysaccharide utilization proved highly variable over the seasons, both in mode and speed, and also by the bacterial clades involved.