Occurrence and diversity of epiphytic bacterial communities on two native plant species in a Michigan Creek

Abstract

We examined the occurrence and diversity of bacteria of different phylogenetic groups in epiphytic assemblages on two native Michigan plant species mayapple (Podophyllum peltatum) and cow parsnip (Heracleum maximum) when the plant leaves were submerged in fresh water. Fresh leaves were incubated in triplicate for about a week within a creek in Hasting, Michigan, and in laboratory microcosm to develop mature epiphytic assemblages. We enumerated bacteria in these assemblages by nucleic acid staining (i.e., total direct counts using 40,6-diamidino-2-phenyllindole) and fluorescent in situ hybridization (FISH), while community diversity was determined based on 16S rRNA gene sequencing. FISH indicated the dominance of members of the-Proteobacterial subclass (20%) on both plant species, while the 16S γRNA gene analysis revealed the predominance of the βProteobacteria (51%) on mayapple and the Fermicutes (26%) on cow parsnip, with the Bacteroidetes present equally within the epiphytic assemblages on both plants. © 2011 Taylor & Francis.