Search results for "Purple sulfur bacteria"

Spatio-temporal distribution and growth dynamics of phototrophic sulfur bacteria populations in the sulfide-rich Lake Arcas

2000

Lake Arcas exhibits a thermal stratification from April to October. A sulfide-rich anoxic hypolimnion is then formed between the deeper part of the thermocline and the lake bottom, and high population densities of phototrophic microorganisms are found at the oxic-anoxic interface. Chromatium weissei, a large rod, 8 × 4 μm in size, was the dominant phototrophic bacterium, reaching densities of up to 1.84 × 106 cells ml-1. Other phototrophic sulfur bacteria, such as Amoebobacter cf. purpureus, Thiocapsa sp., and Pelodictyon clathratiforme were also present in the anoxic hypolimnion, but their cell size and population densities were much lower. Net growth rates (0.125 to —0.123 d-1) and freque…