Response of bacterial communities from California coastal waters to alginate particles and an alginolytic Alteromonas macleodii strain.
Response of bacterial communities from California coastal waters to alginate particles and an alginolytic Alteromonas macleodii strain.
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DOI：
10.1111/1462-2920.13314
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发表时间：
2016-12
影响因子：
5.1
通讯作者：
Maximilian Mitulla;J. Dinasquet;R. Guillemette;M. Simon;F. Azam;Matthias Wietz
中科院分区：
文献类型：
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作者：
Maximilian Mitulla;J. Dinasquet;R. Guillemette;M. Simon;F. Azam;Matthias Wietz
海藻酸盐是海洋大型海藻细胞壁中的一种重要多糖，也是异养细菌的营养来源。藻酸盐可与海水中发现的二价阳离子接触形成凝胶颗粒。在这里，我们测试的假设，藻酸盐凝胶颗粒作为碳源和微生境的海洋细菌，通过添加无菌藻酸盐颗粒的缩影与海水从沿海加州，一个栖息地富含藻酸盐的大型藻类。藻酸盐颗粒迅速定殖和降解，藻酸盐颗粒相关（PA）细菌中的细菌丰度和产量高出三到八倍。16 S rRNA基因扩增子测序显示，藻酸盐PA细菌在接近实验结束时富含与Cryomorphaceae、腐螺菌科（拟杆菌门）和褐腐菌（α变形菌门）相关的OTU。在藻酸盐颗粒和Alteromonas macleodii菌株83-1的微生态系统中，该菌株在群落中占主导地位，并击败了Cryomorphaceae，Saprospiraceae和Phaeoprene，PA水解活性高出50%以上。因此，菌株83-1的藻酸分解活性通过交叉饲喂藻酸水解或其它代谢产物而对非藻酸分解菌株没有益处。考虑到含藻酸盐的大型藻类的全球分布和广泛的生物量，所观察到的与藻酸盐微生境的利用和再矿化相关的细菌动力学促进了对全球富含大型藻类的沃茨中碳循环的理解。
Alginate is a major cell wall polysaccharide from marine macroalgae and nutrient source for heterotrophic bacteria. Alginate can form gel particles in contact with divalent cations as found in seawater. Here, we tested the hypothesis that alginate gel particles serve as carbon source and microhabitat for marine bacteria by adding sterile alginate particles to microcosms with seawater from coastal California, a habitat rich in alginate-containing macroalgae. Alginate particles were rapidly colonized and degraded, with three- to eightfold higher bacterial abundances and production among alginate particle-associated (PA) bacteria. 16S rRNA gene amplicon sequencing showed that alginate PA bacteria were enriched in OTUs related to Cryomorphaceae, Saprospiraceae (Bacteroidetes) and Phaeobacter (Alphaproteobacteria) towards the end of the experiment. In microcosms amended with alginate particles and the proficient alginolytic bacterium Alteromonas macleodii strain 83-1, this strain dominated the community and outcompeted Cryomorphaceae, Saprospiraceae and Phaeobacter, and PA hydrolytic activities were over 50% higher. Thus, alginolytic activity by strain 83-1 did not benefit non-alginolytic strains by cross-feeding on alginate hydrolysis or other metabolic products. Considering the global distribution and extensive biomass of alginate-containing macroalgae, the observed bacterial dynamics associated with the utilization and remineralization of alginate microhabitats promote the understanding of carbon cycling in macroalgae-rich waters worldwide.