BACTERIAL DIVERSITY AND NOVEL HALOPHILIC BACTERIA FROM AN EXTREME HIGH ALTITUDE ANDEAN WETLAND

R.J. MENES, O. ORDOÑEZ, C. ESTEVEZ, M.J. SEUFFERHELD, M.E. FARÍAS.

Cairns, Australia.

Congreso; 12th International Symposium on Microbial Ecology; 2008

International Society for Microbial Ecology (ISME)

INTRODUCTION Vilama Lake (Argentina) is an extreme environment due to the high salinity (80) and arsenic content (12 ppm), UV radiation exposition (max. 8.94 Wm-2 280-312 nm), desiccation conditions and daily temperature fluctuations (-20 to 30 ºC). It is located in the north western of Andean Puna desert at 4,600 m of altitude. With the aim of characterizing the microbial diversity of the ecosystem molecular techniques and isolation were employed MATERIALS AND METHODS Heterotrophic counts Plate count agar, MGM 10, MGM 18 and MGM 25 agar (yeast extract 1 g/L, tryptone 5 g/L, Salt water 30 % :33, 60 or 83 mL/L respectively, agar 15 g/L), Ph 7.5. Incubation: 30 ºC, 10 days aerobically Salt water 30%: NaCl 240 g, MgCl2.6H20 30 g, MgS04.7H20 35 g, KCl 7 g, water q.s. 1000 mL DGGE PCR amplification with Archaeal primers 21F and 1392R with GC clamp. Formamide 20 to 80%.Plate count agar, MGM 10, MGM 18 and MGM 25 agar (yeast extract 1 g/L, tryptone 5 g/L, Salt water 30 % :33, 60 or 83 mL/L respectively, agar 15 g/L), Ph 7.5. Incubation: 30 ºC, 10 days aerobically Salt water 30%: NaCl 240 g, MgCl2.6H20 30 g, MgS04.7H20 35 g, KCl 7 g, water q.s. 1000 mL DGGE PCR amplification with Archaeal primers 21F and 1392R with GC clamp. Formamide 20 to 80%.DGGE PCR amplification with Archaeal primers 21F and 1392R with GC clamp. Formamide 20 to 80%. T-RFLP – PCR amplification with Bacterial primers 27F and 1492R. Digestion withPCR amplification with Bacterial primers 27F and 1492R. Digestion with HhaI and MspI. CONCLUSIONS Vilama lake showed low microbial diversity (3 and 6 T-RFs in water and 2 and 1 T-RFs in sediment with HhaI and MspI respectively for Bacteria and 4 bands in DGGE for Archaea) that was expected from the extreme conditions of the ecosystem The isolation media employed recovered most of the bacteria present however only one archaea was isolated. All of the archaea microorganisms revealed by molecular techniques are unknown speciesI and MspI. CONCLUSIONS Vilama lake showed low microbial diversity (3 and 6 T-RFs in water and 2 and 1 T-RFs in sediment with HhaI and MspI respectively for Bacteria and 4 bands in DGGE for Archaea) that was expected from the extreme conditions of the ecosystem The isolation media employed recovered most of the bacteria present however only one archaea was isolated. All of the archaea microorganisms revealed by molecular techniques are unknown speciesHhaI and MspI respectively for Bacteria and 4 bands in DGGE for Archaea) that was expected from the extreme conditions of the ecosystem The isolation media employed recovered most of the bacteria present however only one archaea was isolated. All of the archaea microorganisms revealed by molecular techniques are unknown species