SEMINAR: OI Seminar Series - Neus Garcias Bonet

Neus Garcias Bonet from IMEDEA – Department of Global Change Research

Title: Diversity of bacterial communities in seagrass tissues

Abstract: This presentation will sum up some of the main results derived from my PhD research, focusing on the assessment of bacterial diversity related to seagrass tissues. Bacterial communities in seagrass meadows have been largely documented but mainly related to sediments. Less information is available in terms of bacterial communities in association with marine plant tissues. Despite the paucity of information on bacteria closely related to seagrasses, there are evidences of the presence of bacteria inside seagrass tissues. We described the bacterial community found in leaves, rhizomes and roots of an endemic Mediterranean seagrass (Posidonia oceanica) by applying molecular methods such as Denaturing Gradient Gel Electrophoresis (DGGE) and subsequent sequencing of the main OTUs identified. The analysis of the sequences allowed the identification of some bacteria that could play key roles in the maintenance of these seagrass meadows. Moreover, we evidenced the presence of putative diazotrophs (i. e. bacteria with nitrogen fixing capabilities) in surface-sterilized roots of P. oceanica by the detection of nifH gene that codes for the nitrogenase enzyme, responsible of nitrogen fixation. Any insight in the bacterial communities present in seagrass tissues could be helpful in order to understand the global decline that seagrass ecosystems are undergoing worldwide.