AME 68:267-272 (2013)  -  DOI: https://doi.org/10.3354/ame01620

ABSTRACT: High bacteriochlorophyll (BChl) concentrations in the anoxic water layers of some humic lakes have indicated that green sulphur bacteria (GSB) may be ecologically significant. The abundance and spatial distribution of GSB were therefore addressed in 13 small humic lakes using fragment analysis and sequencing of PCR-amplified 16S rRNA genes. GSB were detected from lakes where the photosynthetically active radiation was at least 1.1 ?E m^-2 s^-1 at the oxic-anoxic boundary layer. In these lakes, 13 to 42% of the 16S rRNA gene sequences of the anoxic water column were assigned to GSB. The spatial distribution of GSB was tightly correlated with the spectrophotometrically measured BChl concentration during the summer season. Maximum BChl concentrations were observed in the uppermost part of the anoxic water layer, covering most of the chlorophyll pigment in these lakes. The GSB of the humic lakes typically belonged to a phylogenetically homogenous group closely related to Chlorobium clathratiforme.

KEY WORDS: Chlorobium sp. · LH-PCR · Green sulphur bacteria · Humic lake · Boreal lake

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Cite this article as: Karhunen J, Arvola L, Peura S, Tiirola M (2013) Green sulphur bacteria as a component of the photosynthetic plankton community in small dimictic humic lakes with an anoxic hypolimnion. Aquat Microb Ecol 68:267-272. https://doi.org/10.3354/ame01620 Export citation Share:    Facebook - - linkedIn