AME 48:123-130 (2007)  -  doi:10.3354/ame048123

Resistance to burial of cyanobacteria in stromatolites

Jacco C. Kromkamp1,*, Rupert Perkins2, Nicole Dijkman1, Mireille Consalvey3, Miriam Andres4, R. Pamela Reid4

1Netherlands Institute of Ecology, Centre for Estuarine and Marine Ecology (NIOO-CEME), PO Box 140, 4400 AC Yerseke, The Netherlands
2School of Earth, Ocean and Planetary Sciences, Cardiff University, Cardiff CF10 3YE, UK
3National Institute of Water & Atmospheric Research (NIWA), Greta Point, Private Bag 14-901, Kilbirnie, Wellington, New Zealand
4University of Miami/RSMAS-MGG, 4600 Rickenbacker Causeway, Miami, Florida 33149, USA

ABSTRACT: Stromatolites are complex lithified structures with a well-defined layered structure thought to have been formed by trapping and binding of sediment particles by micro-organisms, especially cyanobacteria. Modern marine stromatolites in the Bahamas live in a high-energy environment (surf zone) and are regularly buried by moving sands. We investigated stromatolite cyanobacterial photophysiology ex situ, during and after sand burial using variable fluorescence studies. Buried samples inactivated their photosynthetic electron transport, but only when oxygen concentrations decreased to low levels. Post-burial, the stromatolite cyanobacterial community reactivated its photosynthetic activity within 1 to 2 h, but this activation was light dependent. It is therefore speculated that the redox state of the plastoquinone pool determines the inactivation/reactivation processes. The ability of cyanobacteria to survive and recover from burial by sediment could be a fundamental attribute that has contributed to the success of cyanobacteria as stromatolite builders and for the actual existence of stromatolites as organo-sedimentary structures with a putative presence spanning 3500 million yr.

KEY WORDS: Stromatolite burial · Cyanobacteria · Chlorophyll fluorescence · PSII · State transition

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