Microbial communities in the saturated groundwater environment II: Diversity of bacterial communities in a Pleistocene sand aquifer and their in vitro activities.

摘要: Bacterial cell numbers obtained from 103 water and sediment samples a Pleistocene sandy aquifer in the Lower Rhine region (Bocholt, FRG) were determinated on P-agar by direct count. Below 5 m under surface, colony-forming unit (cfu) less than 100/ml, many cases 50/ml. In samples, they 10- to 100-fold higher (10(2)-10(4) cfu/g dry wt), but changing markedly between different depths. Direct counts yielded two three orders of magnitude higher.About 2,700 strains bacteria 60 isolated randomly characterized morphological physiological properties. Of all isolates, 71.6% gram-negative, 52.2% gram-negative straight rods. Water communities, with one exception, had low proportions gram-positive (<11%), whereas communities percentages isolates three- sevenfold (35-43%). as well sampling sites depths same site, differed their qualitative quantitative morphotype composition capabilities.The vitro activities within single community quite different, indicating that each is composed diverse bacteria, several having extremely capabilities. Thus, has its own specific activity pattern. Gram-positive showed an average lower total did bacteria. Grampositive values corresponding groups water. Many preferred substrates which utilized at high rates. However, there differences degradation various other present, preferences for particular substrates, degraded best.The results morphology physiology studies indicated eight very another diversely structured.