Differences in DNA Fingerprints of Bacterioplankton Community as Affected by Biomass Collection Approaches

To find out different sampling approaches how to affect DNA fingerprinting, environmental genomic DNA was prepared with three sampling approaches. The DNA profiles of 5 bacterial subgroups (alpha-,beta-,gamma-Proteobacteria, Bacteroidetes and Cyanobacteria) and total bacteria were investigated by using denaturing gradient gel electrophoresis (DGGE) fingerprinting. The DGGE patterns showed alpha-Proteobacteria had more free-living OTUs, while gamma-Proteobacteria and Bacteroidetes had more particle-attached OTUs. Cyanobacteria and beta-Proteobacteria had approximately equal OTU number in the two fractions. Principle component analysis based on DNA banding patterns showed there were obvious differences among free-living, particle-attached fraction and whole bacterial community composition of 3 bacterial subgroups (alpha-, gamma-Proteobacteria and Bacteroidetes) and total bacteria, while the patterns of beta-Proteobacteria and Cyanobacteria were similar, suggesting the dynamics of bacterial subgroups can be better understand by combining different collection approaches.