Phototrophic sulfur bacteria in two Spanish lakes: Vertical distribution and limiting factors1

Abstract

The anaerobic zones of Lakes Cis6 and Vilar (Banyoles karstic area, NE Spain) had mass developments of purple sulfur bacteria during summer 1982. In Lake Vilar, Chromatium spp. was dominant (up to 92% of the microbial biovolume). In Lake Ciso, the predominant microorganisms were Chromatium spp. (up to 7 1%) and another purple sulfur bacterium forming aggregates (20%).The bacterial layer could be divided according to the physiological state of the cells into a top part of maximal specific activity, a peak of maximal abundance, and a bottom part of inactive cells. The bacteria in the peak were predominantly limited by light; sulfide, phosphate, and acetate were not limiting in the middle of the day. The light limitation started at the depth having the maximal concentration of cells; the top of the layer appeared to be sulfide-limited. Specific contents of photopigments, elemental sulfur, and reserve polymers decreased from the top to the bottom of the bacterial layer. These phenomena point to the crucial role of light in the development of layers of phototrophic bacteria in stratified lakes.

Seasonal variations in size structure and procaryotic dominance in sulfurous Lake Cisó

“…Maximal depth is 8 m and mean depth is 0.97 m. Morphometry and physicochemical characteristics have been extensively described elsewhere (Guerrero et al 1985). Water inputs are surface runoff and, mostly, seepage.…”

Anaerobic Metabolism: Linkages to Trace Gases and Aerobic Processes

“…Blooms of phototrophic bacteria are observed in lakes (e.g., Guerrero et al, 1985;Overmann, 1997)), microbial mats (Pierson et al, 1987;Van Gemerden, 1993) and in salt marshes (Baas Becking, 1934). Purple nonsulfur bacteria (PNSB) can use a wide variety of organic carbon compounds (Madigan, 1988) and typically thrive in habitats where sulfur and organic carbon loading are high (e.g., sewage effluents).…”

Seasonal change in microbial sulfur cycling in monomictic Lake Fukami‐ike, Japan

“…As compared with purple sulfur bacteria, green sulfur bacteria usually exist at deeper depths because the latter exhibit higher photoenergy conversion efficiency and sulfide tolerance (Pfennig 1975;Guerrero et al 1985). The contribution of anoxygenic photosynthesis to the total primary production in water bodies is 3-5% in lakes of low sulfide concentration (, 0.1 mmol L 21 ) and 20-90% in those of higher sulfide concentration (Takahashi and Ichimura 1968;Culver and Brunskill 1969).…”