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Diel cycle of metabolism of phototrophic purple sulfur bacteria in Lake Cisó (Spain) 1
Author(s) -
van Gemerden Hans,
Montesinos Emilio,
Mas Jordi,
Guerrero Ricardo
Publication year - 1985
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1985.30.5.0932
Subject(s) - sulfur , diel vertical migration , sulfide , glycogen , sulfur cycle , carbon fixation , chemistry , sulfur metabolism , bacteria , phototroph , bloom , environmental chemistry , green sulfur bacteria , biology , botany , biochemistry , photosynthesis , ecology , organic chemistry , genetics
During a bloom of purple sulfur bacteria in Lake Cisó (Spain) data were collected on diel changes in the concentrations of sulfide, sulfur, glycogen, and poly‐ β ‐hydroxybutyrate (PHB), the rates of CO 2 fixation and H 2 S oxidation, and the viability of cells along the vertical profile. During the day, sulfide oxidation resulted in the intracellular accumulation of sulfur and glycogen. At night, the concentrations of glycogen and sulfur decreased concomitant with the production of sulfide and PHB. Throughout the day, CO 2 fixation and H 2 S oxidation were maximal in the zone of maximal population density (peak of the layer); however, in the top of the layer the specific rates were 2–6 times higher. The ratio of CO 2 fixation to H 2 S oxidation, the sulfur content of the cells, and their specific density all indicated that sulfide was predominantly oxidized to sulfur. In the top and the peak of the layer cell viability was high but decreased rapidly with increasing depth. It was concluded that the existence of the bloom is the combined result of slow growth at the peak of the layer and a much faster rate of reproduction at the top of the layer. The cells at the top stored sulfur extensively and then sank to deeper layers where they could not oxidize the sulfur because of insufficient light.