The distribution of cyanobacteria across physical and chemical gradients in hot springs in northern Thailand

Abstract

We mapped the distribution of mat forming cyanobacteria along the thermal gradient from 30 to 80 degrees C, in nine hot spring districts in northern Thailand. Nineteen genera and 36 species were identified by morphometric analysis. Water temperature was the predominant determinant of community structure in the springs. The diversity of cyanobacterial morphotypes fell as temperature increased. Water chemistry (pH, alkalinity and ammonia concentration) was a much weaker descriptor of the floral similarity between the springs. The morphotypes which dominated all springs were Synechococcus lividus and Synechococcus sp. (>40 and <80 degrees C) and Phormidium boryanum (>30 and <60 degrees C). The occurrence of Synechococcus lividus and Synechococcus sp. in every spring at 70 degrees C or more, implied there was no regional barrier to the distribution of these highly thermophilic taxa. Conversely, there were regional differences in the diversity of mat communities growing below 60 degrees C. The most depauperate flora were in the northernmost springs (SKP, TPN, PD, JS) and the springs further south around Chiang Mai had more diverse flora, suggestive of barriers to the dispersal of some taxa. More discriminating analyses using molecular tools will be required to determine whether the ubiquitous distribution Synechoccoccus morphotypes above 60 degrees C masks a genotypic diversity, comparable to the morphotype diversity observed below 60 degrees C.

Distribution of Cyanobacteria in Two Sirch Hot Springs With Regards to the Physicochemical Traits of Water

“…It has been indicated for a long time that most of cyanobacteria are very sensitive to sulfide toxicity and exposing to low concentrations of sulfide, lead to complete and irreversible cessation of light CO 2 fixation (24). Levels of measured nitrate in water samples were variable.…”

Biophysical model of prokaryotic diversity in geothermal hot springs

“…Table 3 in Ref. 24 ); (triangles down) DGGE intensity for all strains, Octopus Springs, Yellowstone National Park from Fig. 1(a) in Ref.…”

Association between physical and geochemical characteristics of thermal springs and algal diversity in Limpopo Province, South Africa

“…They occur in waters with different degrees of salinity, trophicity, organic matter, and hydrogen ions, and at various temperatures. Thermal spring algae communities have long attracted the attention of microbial ecologists because of their unique adaptations to harsh environments (Sompong et al, 2005). Although algae seem to be widespread in thermal waters, some thermophilic organisms have distinctive geographic distribution patterns, with their distribution being limited by their ecological adaptation, resistance and tolerance to extreme environments.…”

“…The diversity of algae in thermal springs is influenced by the mineral composition and water temperature of the spring (Castenholz, 1969;Sember, 2002;Sompong et al, 2005). Generally, diversity of algal species increases from 0°C to 25°C and decreases at temperatures >30°C, while biomass increases with temperature from approximately 0 to 30°C and decreases from 30 to 40°C (Dallas, 2008).…”