Sponsor: National Nature Science Foundation of China (NNSFC)
Headed by Zhang Yongyu
Date: 2011.01-2013.12
As the most abundant organisms in marine ecosystem, viruses mediate microbial population size, community structure and diversity; promote gene transfer between different bacteria and their coevolution; and play important roles in marine biogeochemical cycles. Roseobacter is a dominant bacterial lineage occupying a very important ecological status in coast environment. Whereas, little is known about viruses that infect them.In this project, we focus on: (1) Setting up seveal different host-virus systems by isolating pure cultures of Roseobacter and their viruses from Xiamen coast and nearby estuary environment; (2) Investigating gene transfer and coevolution of Roseobacter and their viruses through comprehensive identification of the isolated roseophages and analyzing the complete genomic sequences of 2-3 roseophages; (3) Studying the kinetic changes of host bacteria throughout the processes of viral infection and revealing the phage resistant mechanisms of several mutated hosts,by using a combined method of atomic force microscopy, confocal microscopy and comparative proteomics. Our aim is to understand the life characteristics of roseophages and their influences on roseobacters in terms of the physiological and biochemical features, gene compositon, and coevolution, providing new insights of the important status and roles of viruses in marine ecosystems.