caa a22 4500 465790216 CHVBK 20180323112021.0 cr unu---uuuuu 170327e19900101xx s 000 0 eng 10.1007/BF02015055 doi (NATIONALLICENCE)springer-10.1007/BF02015055 Microbial community structure and biomass estimates of a methanogenic Antarctic Lake ecosystem as determined by phospholipid analyses [Elektronische Daten] [C. Mancuso, P. Franzmann, H. Burton, P. Nichols] Phospholipid analyses were performed on water column particulate and sediment samples from Ace Lake, a meromictic lake in the Vestfold Hills, Antarctica, to estimate the viable microbial biomass and community structure in the lake. In the water column, methanogenic bacterial phospholipids were present below 17 m in depth at concentrations which converted to a biomass of between 1 and 7×108 cells/liter. Methanogenic biomass in the sediment ranged from 17.7×109 cells/g dry weight of sediment at the surface to 0.1×109 cells/g dry weight at 2 m in depth. This relatively high methanogenic biomass implies that current microbial degradation of organic carbon in Ace Lake sediments may occur at extremely slow rates. Total microbial biomass increased from 4.4×108 cells/ liter at 2 m in depth to 19.4×108 cells/liter at 23 m, near the bottom of the water column. Total nonarchaebacterial biomass decreased from 4.2 ×109 cells/g dry weight in the surface sediment (1/4 the biomass of methanogens) to 0.06×108 cells/g dry weight at 2 m in depth in the sediment. Phospholipid fatty acid profiles showed that microeukaryotes were the major microbial group present in the oxylimnion of the lake, while bacteria dominated the lower, anoxic zone. Sulfate-reducing bacteria (SRB) comprised 25% of the microbial population at 23 m in depth in the water column particulates and were present in the surface sediment but to a lesser extent. Biomass estimates and community structure of the Ace Lake eco-system are discussed in relation to previously measured metabolic rates for this and other antarctic and temperate ecosystems. This is the first instance, to our knowledge, in which the viable biomass of methanogenic and SRB have been estimated for an antarctic microbial community. Springer-Verlag New York Inc., 1990 Mancuso C. Australian Collection of Antarctic Microorganisms, Department of Agricultural Science, University of Tasmania, Box 252C, 7000, Hobart, Tasmania aut Franzmann P. Australian Collection of Antarctic Microorganisms, Department of Agricultural Science, University of Tasmania, Box 252C, 7000, Hobart, Tasmania aut Burton H. Antarctic Division, Channel Highway, 7150, Kingston, Tasmania aut Nichols P. CSIRO Division of Oceanography, GPO Box 1538, 7001, Hobart, Tasmania, Australia aut Microbial Ecology Springer-Verlag 19/1(1990-01-01), 73-95 0095-3628 19:1<73 1990 19 248 https://doi.org/10.1007/BF02015055 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02015055 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Mancuso C. Australian Collection of Antarctic Microorganisms, Department of Agricultural Science, University of Tasmania, Box 252C, 7000, Hobart, Tasmania aut NATIONALLICENCE 700 1- Franzmann P. Australian Collection of Antarctic Microorganisms, Department of Agricultural Science, University of Tasmania, Box 252C, 7000, Hobart, Tasmania aut NATIONALLICENCE 700 1- Burton H. Antarctic Division, Channel Highway, 7150, Kingston, Tasmania aut NATIONALLICENCE 700 1- Nichols P. CSIRO Division of Oceanography, GPO Box 1538, 7001, Hobart, Tasmania, Australia aut NATIONALLICENCE 773 0- Microbial Ecology Springer-Verlag 19/1(1990-01-01), 73-95 0095-3628 19:1<73 1990 19 248 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer