Abstract:Culturable bacteria were isolated from the five different growth stages of Gyrodinium instriatum by gradient dilution method and identified based on sequence of 16S rDNA V3region. A phylogenetic tree was constructed using the twelve sequences in this study and fourteen closest related sequences from GenBank, and the genetic distances were calculated. Meanwhile, bacteria in different growth stages of G. instriatum were analyzed quantitatively. Among the thirty two strains of bacteria isolated, twelve different strains were identified which belonged to Alphaproteobacteria, Gammaproteobacteria, Bacteroidetes, and Actinobacteria. Alphaproteobacteria was the most diversified and abundant group, followed by Bacteroidetes and Actinobacteria. The species number of culturable bacteria ranged from 5to 8in each growth stage, and was highest in the stationary stage but lower in the lag stage and late decline stage. The abundance was lowest in the exponential stage (2.83×106CFU/mL), reached the maxmium in early decline stage (1.72×109CFU/mL), and then slightly decreased in late decline stage (1.37×108CFU/mL). Cluster analysis and multidimensional scaling analysis showed that the bacteria community in early decline stage was quite different from those of the other growth stages, whereas the community stuctures were comparable in the exponential stage and stationary stage when bacteria experienced fast growth. The massive occurrence of a particular bacterium in early decline stage, Acinetobacter baumannii, might be related to the rapid decline of algal cells. Moreover, the ubiqutous Alteromonas macleodii might be play a role in the population competition for G. instriatum. These results suggested that the abundance and community composition in phycosphere bacteria differed in various growth stages of G. instriatum, and bacterial community might play important roles in the growth, population competition, and bloom dynamics of G. instriatum.
王剑, 王朝晖, 熊毅俊. 不同时期条纹环沟藻可培养藻际细菌研究[J]. 中国环境科学, 2014, 34(6): 1540-1547.
WANG Jian, WANG Chao-Hui, XIONG Yi-Jun. Culturable phycosphere bacteria from different growth stages of Gyrodinium instriatum. CHINA ENVIRONMENTAL SCIENCECE, 2014, 34(6): 1540-1547.