Bacterioplankton community in Chesapeake Bay: predictable or random assemblages

350 210 Stroud Water Research Center

Kan, J., B.C. Crump, K. Wang, and F. Chen. 2006. Limnology and Oceanography 51:2157–2169.

doi: 10.4319/lo.2006.51.5.2157


We monitored bacterioplankton communities from Chesapeake Bay over 2 years (2002-2004) by use of denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA gene. Chesapeake Bay bacterioplankton exhibited a repeatable annual pattern and strong seasonal shifts. In winter, the bacterial communities were dominated by Alphaproteobacteria and Actinobacteria, whereas in summer, the predominant bacteria were members of AlphaproteobacteriaGammaproteobacteriaCyanobacteriaActinobacteriaPlanctomycetes, and Bacteroidetes. Phylotypes of Alphaproteobacteria and Actinobacteria present in warm seasons were different from those in cold seasons. Relatively stable communities were present in summer-fall across the sampling years, whereas winter communities were highly variable interannually. Temporal variations in bacterial communities were best explained by changes of chlorophyll a (Chl a) and water temperature, but dissolved oxygen, ammonia, nitrite and nitrate, and viral abundance also contributed significantly to the bacterial seasonal variations.