Archaeal and bacterial diversity in two hot spring microbial mats from a geothermal region in Romania

• Published in: Extremophiles : life under extreme conditions 2013-05, Vol.17 (3), p.523-534
• Main Authors: Coman, Cristian, Drugă, Bogdan, Hegedus, Adriana, Sicora, Cosmin, Dragoş, Nicolae
• Format: Article
• Language: English
• Subjects: Aquatic plants; Archaea; Archaea - classification; Archaea - genetics; Archaea - isolation & purification; Bacteria; Bacteria - classification; Bacteria - genetics; Bacteria - isolation & purification; Biochemistry; Biodiversity; Biomedical and Life Sciences; Biotechnology; DNA, Archaeal - chemistry; DNA, Bacterial - chemistry; Euryarchaeota; Fischerella; Geitlerinema; Geothermal power; Hot springs; Hot Springs - microbiology; Leptolyngbya; Life Sciences; Methanococcus; Microbial activity; Microbial Consortia; Microbial Ecology; Microbiology; Original Paper; Proteobacteria; Regions; Romania; Taxa; Thauera; Water temperature
• ISSN: 1431-0651; 1433-4909
• DOI: 10.1007/s00792-013-0537-5

The diversity of archaea and bacteria was investigated in two slightly alkaline, mesophilic hot springs from the Western Plain of Romania. Phylogenetic analysis showed a low diversity of Archaea, only three Euryarchaeota taxa being detected: Methanomethylovorans thermophila , Methanomassiliicoccus luminyensis and Methanococcus aeolicus . Twelve major bacterial groups were identified, both springs being dominated by Cyanobacteria, Chloroflexi and Proteobacteria. While at the phylum/class-level the microbial mats share a similar biodiversity; at the species level the geothermal springs investigated seem to be colonized by specific consortia. The dominant taxa were filamentous heterocyst-containing Fischerella , at 45 °C and non-heterocyst Leptolyngbya and Geitlerinema , at 55 °C. Other bacterial taxa ( Thauera sp., Methyloversatilis universalis , Pannonibacter phragmitetus , Polymorphum gilvum , Metallibacterium sp. and Spartobacteria) were observed for the first time in association with a geothermal habitat. Based on their bacterial diversity the two mats were clustered together with other similar habitats from Europe and part of Asia, most likely the water temperature playing a major role in the formation of specific microbial communities that colonize the investigated thermal springs.