TheIsolationandIncubationofHeterotrophicBacteria,OligotrophicBacteriaandPhotosyntheticBacteriaasWell As TheCorrelation Between The Distributions Of These Three Types Bacteria And The Environmental Factors In Yangtse River Estuary And Its Adjacent Sea

The samples were taken on the cruise in the Yangtse River estuary and the East sea from Sep to Oct in 2003. With the use of in situ incubation, separation and identification of marine planktonic heterotrophic bacteria, oligotrophic bacteria and photosynthetic bacteria, two bacteria, Micrococcus varians and Micrococcus roseus, were obtained and identified; combined the bacteria colonies data with in situ survey data on depth, temperature, salinity, turbidity, fluorescence and inorganic nutrient, the relationship of these three types bacteria and correlated setting factors and the distribution were discussed. The conclusions were as follows: The 30 salinity line of Yangtse River estuary was a characteristic borderline, the distributions of these three types bacteria were quite difference on the two sides of this line; The nitrate concentration (l(imol/L) in the surface layer was a characteristic concentration, the three types bacteria were less limited by DOC in the sea area where the nitrate concentration was over lμmol/L than where the nitrate concentration was under lμmol/L; The main regulating and limiting factors to the different bacteria were different in the same sea area and same ecosystem; The main limiting factors to the number of planktonic heterotrophic bacteria were the water temperature and phytoplankton in summer; From the estuary to the outside sea area, the number of oligotrophic bacteria was influenced more and more by water temperature, but the nutrient's influence and limitation to the number of oligotrophic bacteria became less and less; In the area of Yangtse River estuary, the key limiting factor to the growth of photosynthetic bacteria was turbidity, in the outside area of Yangtse River estuary, the main limiting factors were the illumination and photosynthetic autotrophy; In this area the planktonic bacteria was limited by DOC, the function of oligotrophic bacteria and photosynthetic bacteria in microbial food loop was more important than the heterotrophic bacteria's. Finally fluorescence in situ hybridization (FISH) with rRNA-targeted ohgonucleotide probes on membrane filters was preliminarily applied in the analysis of marine AAP bacteria.