Distribution Characteristics Of Bacterioplankton And Virioplankton And Bacterial Diversity In Sediments In Coastal Lines Of Shandong

Based on four cruises from August, 2006 to October, 2007, the distribution patterns of cultivable heterotrophic bacteria biomass (CHBB), virioplankton and bacterioplankton abundance (BA) in coastal waters of Shandong were studied. Moreover, the relationships between them and the environmental ecological factors, temperature, dissolved oxygen (DO), chlorophyll a (Chl a), total N, total P, total organic carbon, NO3- and PO43- in summer and winter were also analyzed. At the same time, bacterial diversity in sediments of station QD08 and QD13 were also investigated used the method of ARDRA.1. Distribution of cultivable heterotrophic bacteria (CHBB)Cultivable heterotrophic bacteria biomass fluctuated between 1.01×104CFU/L and 6.27×107CFU/L in the four seasons. The highest number was detected in the substrate waters of station QD15 in summer, while the CHBB was lowest in middle layer water of station QD03 in winter. The highest CHBB in water columns in different stations was recorded during summer, the second highest CHBB occurred in winter and the lowest was in spring. The CHBB decreased with the distance far away from the coast on most of transects in summer, winter and august. There was no distinct spatial distribution pattern of the CHBB in vertical section.The CHBB has highly significant correlations (P < 0.01) with total nitrogen, phosphorus and PO43-, which indicated that the CHBB might be influenced by these environmental factors in summer and winter. No correlation was detected between CHBB and temperature and the Chl a.2. Distribution of bacterioplankton abundance and biomassThe abundance and biomass of bacterioplankton in coastal waters of Shandong was 9.76×108~1.55×1010cells/L and 14.79~236.49μg/L respectively. The distribution of bacterioplankton abundance and biomass almost demonstrated the same temporal and spatial pattern. The bacterioplankton abundance and biomass were much lower in winter than in the other three seasons. The highest bacterioplankton abundance and biomass in water columns were occurred in spring, while the second in summer. There was no distinct spatial distribution pattern of the bacterioplankton abundance and biomass in vertical section. The bacterioplankton abundance and biomass were higher in the coastal line area in spring, august and winter. Most of the highest bacterioplankton abundance areas were around Jiaozhou bay, Xiaodao bay and Dingzi bay.The correlations were highly significant between bacterioplankton abundance, biomass and temperature, total organic carbon and Chl a in summer and winter. At the mean time, bacterioplankton and biomass were negative correlated with DO and PO43-. The distribution of bacterioplankton abundance and biomass were affected by the environmental ecological factors above.3.Distribution of virioplankton abundanceThe virioplankton abundance was between 1.71×109 VLPs/L and 3.40×1011 VLPs/L in the four cruises. The highest virioplankton abundance was recorded during winter, the second highest virioplankton abundance occurred in spring and the lowest in august. Salinity and DO content in sea water were regarded as the main factors which leaded to the seasonal variation of virioplankton abundance. The distribution of virioplankton abundance in the four seasons almost demonstrated the same pattern, which showed higher abundance in the costal line.Virioplankton abundance was significant positive correlated with NO3- content in the sea water, and was weak negative correlated with bacterioplankton abundance and Chl a. NO3- content might be the primary factor which effected the distribution of virioplankton abundance in summer and winter.4.Bacterial diversity in the sediment of QD08 and QD13Bacterial diversity in the sediment of stations QD08 and QD13 were studied in summer, winter, and spring, august. 16S rDNA fragments of bacteria were amplified and libraries were constructed based on the purified DNA extracted from the sediments of station QD08 and QD13. In the station of QD08, the numbers of positive clones which have different enzyme digest maps were 37, 48, 48 and 39. The numbers of positive clones were 33, 29, 57 and 57 respectively in the station of QD13. The 16S rDNA sequences which these clones contented were than sequedced. The results indicated that the coverage C of A8S, D8S, A13S and B13S libraries are very high, while the coverage C of B8S, C8S, C13S and D13S libraries all below 80%.In the station QD08, the sequenced clones fell into nine major lineages of the domain bacteria: the alpha, gamma, delta and epsilon Proteobacteria, Plancomycene, Actinobacteria, Gemmatimonadetes, Acidobacteriaceae, Nitrospirales, Verrucomicrobial, Bacteroidetes and Chloroflexi. The sub class of Proteobacteria, especially gamma Proteobacteria predominated in this station. The results suggested that these clones were very diverse in phylogeny. In the station of QD13, the domain bacteria included the alpha, gamma, delta and epsilon Proteobacteria, Plancomycene, Gemmatimonadetes, Acidobacteriaceae, Nitrospirales, Bacteroidetes, Chloroflexi, Actinobacteria and Clostridiales.Compared to the station QD13, seasonal variation of bacteria diversity in the sediment of QD08 seemed to be very small. This phenomenon might indicate that the sediment environment did not change much during the year.