POSTER: Identifying the Microbial Community in the Phycosphere of Microcystis aeruginosa
Research Mentor: Dr. Hidetoshi Urakawa
Additional Authors: Dr. Hidetoshi Urakawa, Taylor L. Hancock
Abstract:
Microcystis aeruginosa is a representative freshwater cyanobacterium and is known to form a phycosphere, with other microorganisms to create a mutualism or commensalism relationship. These satellite microorganisms may play an important role for M. aeruginosa in the surface bloom formation. We aim to identify the microbial community in the phycosphere of several Microcystis aeruginosa cultures. To identify the heterotrophic bacteria living in the phycosphere of different M. aeruginosa host strains, heterotrophic bacteria were first isolated with Luria broth agar plates and partial 16S rRNA gene sequence were determined. The 16S rRNA gene sequences were analyzed using MEGA software. The isolated bacteria were members of different classes such as Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria and Actinobacteria. Majority of the isolates are Plant Growth Promoting Bacteria (PGPB) such as Rhizobium, Sphingomonas, and Microbacterium. Other satellites belonged to lineages known as an inhibitor, such as Delftia, or as an indicator for M. aeruginosa being in a terminal state such as Stenotrophomonas sp. Microbial diversity within the phycosphere will vary depending on the conditions and state that M. aeruginosa is found in. This will influence the Microcystis-associated bacteria and could amplify different relationship. Further investigation is required to have an in depth understanding of the different relationships M. aeruginosa has with its satellites.