ABSTRACT
Methane-forming bacteria contain unusual phytanylglycerol ether phospholipids which can be extracted from the bacteria in sediments and assayed quantitatively by high performance liquid chromatography (HPLC). In this procedure the lipids were extracted, the phospholipids recovered, hydrolyzed, purified by thin layer chromatography, derivatized and assayed by HPLC. Ether lipids were recovered quantitatively from Methanobacterium thermoautotrophicum and sediments at levels as low as 8 x 10(-14) moles. In freshwater and marine sediments the flux of methane to the atmosphere and the methane levels in the pore water reflects the recovery of the phytanyl glycerol ether lipid 'signature'. The proportion of the ether phospholipid to the total recoverable phospholipid was highest in anaerobic digester sewage sludge and deeper subsurface freshwater sediment horizons.
Subject(s)
Biomass , Environmental Microbiology , Geologic Sediments/analysis , Glyceryl Ethers/analysis , Methanobacterium/metabolism , Phospholipid Ethers/analysis , Chromatography, High Pressure Liquid , Chromatography, Thin Layer , Fresh Water , Geologic Sediments/chemistry , Geologic Sediments/microbiology , Glyceryl Ethers/isolation & purification , Hydrolysis , Methane/metabolism , Methanobacterium/physiology , Phospholipid Ethers/isolation & purification , Phospholipids/analysis , Phospholipids/isolation & purification , SewageABSTRACT
An airborne gas-filter correlation analyzer was designed and assembled to monitor atmospheric trace gases. Flight tests indicated that a methane version of this nondispersive infrared instrument performed properly while measuring CH(4) concentration profiles as small as 1 ppm from altitudes of 0.15 up to 1.2 km. A unique multiple chopping scheme was developed to simplify the gas-filter technique and to provide an easy mechanical nulling procedure. The single-beam rotating-cell optical system integrated with a multipass sampling cell and the signal processing circuit are described in detail.
