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Protection of cells from salinity stress by extracellular polymeric substances in diatom biofilms

Steele, Deborah J and Franklin, Daniel J and Underwood, Graham JC (2014) 'Protection of cells from salinity stress by extracellular polymeric substances in diatom biofilms.' Biofouling, 30 (8). pp. 987-998. ISSN 0892-7014

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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, Fq′/Fm′, within 4% of pre-shock values, whereas Fq′/Fm′ 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.

Item Type: Article
Uncontrolled Keywords: biofilm; diatoms; Cylindrotheca; exopolymer; sea ice; salinity; xanthan gum
Subjects: Q Science > QH Natural history > QH301 Biology
Divisions: Faculty of Science and Health
Faculty of Science and Health > Life Sciences, School of
SWORD Depositor: Elements
Depositing User: Elements
Date Deposited: 23 Jun 2015 13:37
Last Modified: 15 Jan 2022 00:33

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