Protection of cells from salinity stress by extracellular polymeric substances in diatom biofilms.
Protection of cells from salinity stress by extracellular polymeric substances in diatom biofilms.
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DOI：
10.1080/08927014.2014.960859
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发表时间：
2014-09
期刊：
影响因子：
2.7
通讯作者：
Underwood GJ
中科院分区：
文献类型：
--
作者：
Steele DJ;Franklin DJ;Underwood GJ
硅藻生物膜在海洋环境中非常丰富。据推测（但未经检验），硅藻产生的胞外聚合物（EPS），使细胞能够科普波动的盐度。为了确定EPS的保护作用，将新月藻生长在黄原胶中，盐度为35、50、70和90 ppt。黄原胶基质显著增加细胞活力（由SYTOX-Green测定）、生长速率和群体密度，分别高达300、2，300和200%。硅藻生长在0.75%w/v黄原胶，进行急性盐休克处理（盐度17.5，50，70和90 ppt）保持光合能力，Fq ′/Fm ′，在4%的冲击前的值，而Fq ′/Fm ′在细胞生长没有黄原胶下降高达64%的高盐休克。在标准盐度下，黄原胶中形成的生物膜有助于细胞在盐度休克期间维持功能。这些结果为生活在EPS基质中的生物膜硅藻的益处提供了证据。
Diatom biofilms are abundant in the marine environment. It is assumed (but untested) that extracellular polymeric substances (EPS), produced by diatoms, enable cells to cope with fluctuating salinity. To determine the protective role of EPS, Cylindrotheca closterium was grown in xanthan gum at salinities of 35, 50, 70 and 90 ppt. A xanthan matrix significantly increased cell viability (determined by SYTOX-Green), growth rate and population density by up to 300, 2,300 and 200%, respectively. Diatoms grown in 0.75% w/v xanthan, subjected to acute salinity shock treatments (at salinities 17.5, 50, 70 and 90 ppt) maintained photosynthetic capacity, F q ′/F m ′, within 4% of pre-shock values, whereas F q ′/F m ′ in cells grown without xanthan declined by up to 64% with hypersaline shock. Biofilms that developed in xanthan at standard salinity helped cells to maintain function during salinity shock. These results provide evidence of the benefits of living in an EPS matrix for biofilm diatoms.