Institutional Research Information Service
UCL Logo
Please report any queries concerning the funding data grouped in the sections named "Externally Awarded" or "Internally Disbursed" (shown on the profile page) to your Research Finance Administrator. Your can find your Research Finance Administrator at http://www.ucl.ac.uk/finance/research/post_award/post_award_contacts.php by entering your department
Please report any queries concerning the student data shown on the profile page to:

Email: portico-services@ucl.ac.uk

Help Desk: http://www.ucl.ac.uk/ras/portico/helpdesk
Publication Detail
Surface charge and zeta-potential of metabolically active and dead cyanobacteria
  • Publication Type:
    Journal article
  • Publication Sub Type:
    Journal Article
  • Authors:
    Martinez RE, Pokrovsky OS, Schott J, Oelkers EH
  • Publication date:
  • Pagination:
    317, 325
  • Journal:
    Journal of Colloid and Interface Science
  • Volume:
  • Issue:
  • Status:
  • Print ISSN:
Zeta potential and acid-base titrations of active, inactivated, and dead Planktothrix sp. and Synechococcus sp. cyanobacteria were performed to determine the degree to which cell surface electric potential and proton/hydroxyl adsorption are controlled by metabolism or cell membrane structure. Surface OH- excess from potentiometric data, showed differences in surface charge between active and dead cyanobacteria from pH 3 to 10. Average zero salt effect pH (pHpzse) of 5.8 ± 0.1 and 6.3 ± 0.1 were obtained for active Planktothrix sp. and Synechococcus sp., respectively. Similarly for dead cyanobacteria pHpzse values of 5.8 ± 0.1 and 4.6 ± 0.1 were obtained. Zeta potentials of active Planktothrix sp. and Synechococcus sp. were positive at alkaline conditions, with a maximum of + 13.7 ± 1.5   mV at a pH of 9.0 ± 0.1 for both species. This positive potential diminished in the presence of 1 mM HCO-3. The zeta potential of Planktothrix sp. and Synechococcus sp. cells was negative at alkaline pH following their exposure to NaN3, a metabolic inhibitor. The zeta potential of dead cyanobacteria was negative for Planktothrix sp., from pH 2.5 to 10.5, at -30 to - 20   mV. Dead Synechococcus sp. exposed to a pH 2.5 solution recorded negative potentials to a minimum of - 30   mV at pH 8, but positive potentials were found at higher pH reaching a maximum of + 10   mV at pH 9.1. Zeta potentials for dead, but non-acidified Synechococcus sp. remained negative at - 30   mV from an initial pH of 5.6 to 10.5, reflecting differences in cell wall structure between these species. These results indicate that Planktothrix sp. and Synechococcus sp. may metabolically control their surface charge to electrostatically attract bicarbonate anions at alkaline pH, required for photosynthesis. © 2008 Elsevier Inc. All rights reserved.
Publication data is maintained in RPS. Visit https://rps.ucl.ac.uk
 More search options
There are no UCL People associated with this publication
University College London - Gower Street - London - WC1E 6BT Tel:+44 (0)20 7679 2000

© UCL 1999–2011

Search by