Multidisciplinary evidences that Synechocystis PCC6803 exopolysaccharides operate in cell sedimentation and protection against salt and metal stresses.
Multidisciplinary evidences that Synechocystis PCC6803 exopolysaccharides operate in cell sedimentation and protection against salt and metal stresses.
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DOI：
10.1371/journal.pone.0055564
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Chauvat F
中科院分区：
文献类型：
--
作者：
Jittawuttipoka T;Planchon M;Spalla O;Benzerara K;Guyot F;Cassier-Chauvat C;Chauvat F
外界对蓝藻胞外多糖（EPS）的产生知之甚少，也没有遗传和生理证据表明EPS参与细胞抵御盐和金属引起的环境胁迫。我们研究了四种EPS产生基因，sll0923, sll1581， slr1875和sll5052，在蓝藻胞杆菌PCC6803模型中，产生大量的EPS附着在细胞上（CPS）并释放到培养基（RPS）中，如图所示。我们发现sll0923、sll1581、slr1875和sll5052在没有胁迫的情况下都是所有相应的单缺失和双缺失突变体生长所必需的。此外，我们报告sll0923， sll1581和slr1875明确地在CPS和RPS的生产中起作用。sll1581和slr1875在CPS生产中都比sll0923更重要，而在RPS生产中则相反。我们发现，sll1581和slr1875的大部分EPS缺失突变体缺乏包围WT细胞并吸收其附近铁元素的EPS套。利用该突变体，我们首次证明了蓝藻EPS直接作用于细胞对NaCl、CoCl2、CdSO4和铁饥饿的保护。我们相信，我们的EPS耗尽突变体将成为研究EPS在细胞间聚集、生物膜形成、生物矿化和对环境胁迫的耐受性中的作用的有用工具。我们还建议使用快速沉淀突变体作为生物技术细胞工厂，以促进生产细胞生物量和/或从生长介质中排泄的产物中分离的昂贵收获。
Little is known about the production of exopolysaccharides (EPS) in cyanobacteria, and there are no genetic and physiological evidences that EPS are involved in cell protection against the frequently encountered environmental stresses caused by salt and metals. We studied four presumptive EPS production genes, sll0923, sll1581, slr1875 and sll5052, in the model cyanobacterium Synechocystis PCC6803, which produces copious amounts of EPS attached to cells (CPS) and released in the culture medium (RPS) as shown here. We show that sll0923, sll1581, slr1875 and sll5052 are all dispensable to the growth of all corresponding single and double deletion mutants in absence of stress. Furthermore, we report that sll0923, sll1581 and slr1875 unambiguously operate in the production of both CPS and RPS. Both sll1581 and slr1875 are more important than sll0923 for CPS production, whereas the contrary is true for RPS production. We show that the most EPS-depleted mutant, doubly deleted for sll1581 and slr1875, lacks the EPS mantle that surrounds WT cells and sorbs iron in their vicinity. Using this mutant, we demonstrate for the first time that cyanobacterial EPS directly operate in cell protection against NaCl, CoCl2, CdSO4 and Fe-starvation. We believe that our EPS-depleted mutants will be useful tools to investigate the role of EPS in cell-to-cell aggregation, biofilm formation, biomineralization and tolerance to environmental stresses. We also suggest using the fast sedimenting mutants as biotechnological cell factories to facilitate the otherwise expensive harvest of the producer cell biomass and/or its separation from products excreted in the growth media.
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影响因子：
3.2
作者：
LABARRE, J;CHAUVAT, F;THURIAUX, P
通讯作者：
THURIAUX, P
影响因子：
3.5
作者：
Rigano, Luciano A.;Siciliano, Florencia;Marano, Maria Rosa
通讯作者：
Marano, Maria Rosa
影响因子：
14.8
作者：
Heckman, Karin L.;Pease, Larry R.
通讯作者：
Pease, Larry R.
影响因子：
2.1
作者：
Griese, Marco;Lange, Christian;Soppa, Joerg
通讯作者：
Soppa, Joerg
影响因子：
3.2
作者：
Conover, Matt S.;Redfern, Crystal J.;Deora, Rajendar
通讯作者：
Deora, Rajendar