Community structure of free-floating filamentous cyanobacterial mats from the Wonder Lake geothermal springs in the Philippines.


Journal Article

Cyanobacterial mats were characterized from pools of 45-60 degrees C in near-neutral pH, low-sulphide geothermal springs in the Philippines. Mat structure did not vary with temperature. All mats possessed highly ordered layers of airspaces at both the macroscopic and microscopic level, and these appear to be an adaptation to a free-floating growth habit. Upper mat layers supported biomass with elevated carotenoid:chlorophyll a ratios and an as yet uncharacterized waxy layer on the dorsal surface. Microscopic examination revealed mats comprised a single Fischerella morphotype, with abundant heterocysts throughout mats at all temperatures. Molecular analysis of mat community structure only partly matched morphological identification. All samples supported greater 16S rDNA-defined diversity than morphology suggested, with a progressive loss in the number of genotypes with increasing temperature. Fischerella-like sequences were recovered from mats occurring at all temperatures, but some mats also yielded Oscillatoria-like sequences, although corresponding phenotypes were not observed. Phylogenetic analysis revealed that Fischerella-like sequences were most closely affiliated with Fischerella major and the Oscillatoria-like sequences with Oscillatoria amphigranulata.

Full Text

Cited Authors

  • Lacap, DC; Smith, GJD; Warren-Rhodes, K; Pointing, SB

Published Date

  • July 2005

Published In

Volume / Issue

  • 51 / 7

Start / End Page

  • 583 - 589

PubMed ID

  • 16175207

Pubmed Central ID

  • 16175207

Electronic International Standard Serial Number (EISSN)

  • 1480-3275

International Standard Serial Number (ISSN)

  • 0008-4166

Digital Object Identifier (DOI)

  • 10.1139/w05-038


  • eng