Stratified Distribution of Nutrients and Extremophile Biota within Freshwater Ice Covering the Surface of Lake Baikal

• Published in: The journal of microbiology Vol. 50; no. 1; pp. 8 - 16
• Main Authors: Bondarenko, Nina A., Limnological Institute, Siberian Branch of Russian Academy of Sciences, Ulan-Batorskaya, Irkutsk, Russia, Belykh, Olga I., Limnological Institute, Siberian Branch of Russian Academy of Sciences, Ulan-Batorskaya, Irkutsk, Russia, Golobokova, Ludmila P., Limnological Institute, Siberian Branch of Russian Academy of Sciences, Ulan-Batorskaya, Irkutsk, Russia, Artemyeva, Olga V., Limnological Institute, Siberian Branch of Russian Academy of Sciences, Ulan-Batorskaya, Irkutsk, Russia, Logacheva, Natalia F., Limnological Institute, Siberian Branch of Russian Academy of Sciences, Ulan-Batorskaya, Irkutsk, Russia, Tikhonova, Irina V., Limnological Institute, Siberian Branch of Russian Academy of Sciences, Ulan-Batorskaya, Irkutsk, Russia, Lipko, Irina A., Limnological Institute, Siberian Branch of Russian Academy of Sciences, Ulan-Batorskaya, Irkutsk, Russia, Kostornova, Tatyana Ya., Limnological Institute, Siberian Branch of Russian Academy of Sciences, Ulan-Batorskaya, Irkutsk, Russia, Parfenoya, Valentina V., Limnological Institute, Siberian Branch of Russian Academy of Sciences, Ulan-Batorskaya, Irkutsk, Russia, Khodzher, Tamara V., Limnological Institute, Siberian Branch of Russian Academy of Sciences, Ulan-Batorskaya, Irkutsk, Russia, Ahn, T.S., Kangwon National University, Chuncheon, Republic of Korea, Zo, Young-Gun, Kyungsung University, Busan, Republic of Korea
• Format: Journal Article
• Language: English
• Published: Heidelberg The Microbiological Society of Korea 01.02.2012; Springer Nature B.V; 한국미생물학회
• Subjects: ACTINOMYCETALES; Algae; Aquatic ecosystems; Aquatic plants; BACILLARIOPHYCEAE; Bacteria; bacterial communities; bioactive properties; Biodiversity; biomass; Biomedical and Life Sciences; Biota; Cellulose acetate; CHEMICAL COMPOSITION; Chemical elements; Chlorophyta; cold; COMPOSICION QUIMICA; COMPOSITION CHIMIQUE; Cyanobacteria; Cyanobium; Detritus; ecosystems; extremophiles; food chain; Freezing; Fresh Water - chemistry; Fresh Water - microbiology; Freshwater; Freshwater ecosystems; Freshwater ice; Freshwater lakes; Ice; Ice - analysis; ice organisms; Lake Baikal; Life Sciences; Microbiology; Microorganisms; mycelium; Nitrates; Nitrates - analysis; Nutrients; phosphorus; Phosphorus - analysis; picoplankton; Plankton; River ecology; Silica; Silicon Dioxide - analysis; Synechococcus; Yeasts; 생물학; Lake Baikal; South Korea; Russia; Russia, Siberia, Baykal L; freshwater ice; actinomycetes; diatoms; picoplankton; chemical composition; ice organisms
• ISSN: 1225-8873; 1976-3794; 1976-3794
• DOI: 10.1007/s12275-012-1251-1

Biological entities and gradients of selected chemicals within the seemingly barren ice layers covering Lake Baikal were investigated. Ice cores 40-68 cm long were obtained from inshore and offshore sites of Southern Lake Baikal during the cold period of a year (March-April) in 2007 and 2008. In microscopic observations of the melted ice, both algae and bacteria were found in considerable numbers (greater than 10³ cells/L and greater than 10⁴ cells/ml, respectively). Among all organisms found, diatom was generally the most predominant taxon in the ice. Interestingly, both planktonic and benthic algae were present in considerable numbers (2-4×10⁴ cells/L). Dominant phototrophic picoplankton were comprised of small green algae of various taxa and cyanobacteria of Synechococcus and Cyanobium. The bacterial community consisted mostly of short rod and cocci cells, either free-living or aggregated. Large numbers of yeast-like cells and actinomycete mycelium were also observed. Concentrations of silica, phosphorus, and nitrate were low by an order of magnitude where biota was abundant. The profile of the ice could be interpreted as vertical stratification of nutrients and biomass due to biological activities. Therefore, the organisms in the ice were regarded to maintain high activity while thriving under freezing conditions. Based on the results, it was concluded that the freshwater ice covering the surface of Lake Baikal is considerably populated by extremophilic microorganisms that actively metabolize and form a detritus food chain in the unique large freshwater ecosystem of Lake Baikal.