Planktonic Bacterial Genetic Diversity Analysis Of T-rflp Method

Bacteria community plays an important role in aquatic ecosystems. Traditional methodologies for aquatic microbial biodiversity analysis are based on culture of microorganisms, which results in serious change in the microbial community structure. In order to overcome the shortages of traditional methodology, a novel T-RFLP technique was studied in this article. The purpose is to understand its theory, methodology and application, so that the author can apply it in the study of molecular microbial ecology.In this study, T-RFLP has been carried out for field samples, liquid and plate cultures. Results show that PCR primer selection also plays decisive role in the methodology. Two primer pairs considered universal to Domain Bacteria in previous reports did not work on our field sample. Another universal primers pair (S-D-Bact-0011-a-S-17/S-D-Bact-1512-a-A-16) was proved to be efficient for the field samples. T-RFLP patterns of the plate cultures revealed at least 3 different groups. On the other hand, at least 22 different groups of bacteria are recognized in 0.2pm membrane sample. 1um membrane samples consist of at least 4 groups of bacteria. The free living and particle - attached bacteria groups are significantly different in term of species composition. Plate culture strains are different from dominant field groups. This result proved the insufficiency of traditional cultural methodology.