Cyanobacterial diversity of hot sprin gs in high –level natural radiation Areas

There are several places in the world, where the level of natural radiation is unusually high, such as some regions of Ramsar and Abeg arm-e- Mahallat in Iran. Hot mineral springs in Iran are very attractive to people who seek physical healing but some of them are also unique environments due to high natural radi oactive elements that may be contained in the hot mineral water. Extremophile cyanobacteria inhabiting hot springs are very attractive for science research. In this study, 10 hot springs were inv estigated in high-level natural radiation areas of Iran. The effects of high 226Ra concentration were studied on cyanobacterial diversity in this regions. The 226Ra content of water and soil samples were detected. The highest concentrations, 13000Bq kg_1 were measured in the soil and 130Bq l -1 in the water. Seventy-nine cyanobacteria spec ies were identified. The most frequent and widely distributed taxa were Leptolyngbya sp. and Pho rmidium sp. According to results of spatial vari ation of mats species, regional specificity was observed. In this study, was observed that the springs with high temperature or high radiation h ave low cyanobacterial diversity. The highest b iodiversity was displayed by Saddat Mahalleh so urce with the lowest water 226Ra concentration in Ramsar hot springs. Results showed that 226Ra activity, pH and Temperature were importantly environmental factors influencing the distrib ution of cyanobacteria. The morphological an d molecular analyses revealed, that the strains are not classifiable to any existing taxon. The refore, they are described as new taxa for science. Based on results of our study, two earlier described species are transferred into newly established genus. To the best of our knowledg e, this is the first report on the cyanobacterial diversity isolated from HLNRAs in Iran.

There are several places in the world, where the level of natural radiation is unusually high, such as some regions of Ramsar and Abeg arm-e- Mahallat in Iran. Hot mineral springs in Iran are very attractive to people who seek physical healing but some of them are also unique environments due to high natural radi oactive elements that may be contained in the hot mineral water. Extremophile cyanobacteria inhabiting hot springs are very attractive for science research. In this study, 10 hot springs were inv estigated in high-level natural radiation areas of Iran. The effects of high 226Ra concentration were studied on cyanobacterial diversity in this regions. The 226Ra content of water and soil samples were detected. The highest concentrations, 13000Bq kg_1 were measured in the soil and 130Bq l -1 in the water. Seventy-nine cyanobacteria spec ies were identified. The most frequent and widely distributed taxa were Leptolyngbya sp. and Pho rmidium sp. According to results of spatial vari ation of mats species, regional specificity was observed. In this study, was observed that the springs with high temperature or high radiation h ave low cyanobacterial diversity. The highest b iodiversity was displayed by Saddat Mahalleh so urce with the lowest water 226Ra concentration in Ramsar hot springs. Results showed that 226Ra activity, pH and Temperature were importantly environmental factors influencing the distrib ution of cyanobacteria. The morphological an d molecular analyses revealed, that the strains are not classifiable to any existing taxon. The refore, they are described as new taxa for science. Based on results of our study, two earlier described species are transferred into newly established genus. To the best of our knowledg e, this is the first report on the cyanobacterial diversity isolated from HLNRAs in Iran.