title: Effects of viruses on bacterial functions under contrasting nutritional conditions for four species of bacteria isolated from Hong Kong waters.
abstract: Free living viruses are ubiquitous in marine waters and concentrations are usually several times higher than the bacterial abundance. These viruses are capable of lysing host bacteria and therefore, play an important role in the microbial loop in oligotrophic waters. However, few studies have been conducted to compare the role of viruses in regulating bacterial abundance and heterotrophic activities between natural oligotrophic waters and anthropogenic influenced eutrophic waters. In this study, we examined viral effects on bacterial functions of four single bacterial species incubated with natural viral assemblages in seawater samples from eutrophic and oligotrophic waters. The viral-lysis of bacteria was significantly higher in eutrophic than oligotrophic waters. This suggests that viruses were capable of controlling bacterial abundance, respiration and production in the eutrophic waters. Cellular bacterial respiration and production was higher with viruses than without viruses, which was more evident in the oligotrophic waters. These results indicate that viruses can slow down bacterial consumption of oxygen and reduce bacteria-induced eutrophication effects in anthropogenic eutrophic waters, but switch to the role of sustaining the bacterial population when nutrients are limiting. There were bacterial species differences in resisting viral attack, which can influence the dominance and biodiversity of bacterial species in coastal waters.
authors.affiliation: School of Marine Sciences, Sun Yat-sen University, Guangzhou, China, 510006.|Key Laboratory of Marine Resources and Coastal Engineering in Guangdong Province, Guangzhou, China, 510006.
authors.forename: Hao
authors.initials: H
authors.lastname: Liu
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China.
authors.forename: Xiangcheng
authors.initials: X
authors.lastname: Yuan
authors.affiliation: State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Xu
authors.affiliation: Department of Earth and Ocean Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Harrison
authors.affiliation: School of Marine Sciences, Sun Yat-sen University, Guangzhou, China, 510006.|Key Laboratory of Marine Resources and Coastal Engineering in Guangdong Province, Guangzhou, China, 510006.
authors.forename: Lei
authors.initials: L
authors.lastname: He
authors.affiliation: School of Marine Sciences, Sun Yat-sen University, Guangzhou, China, 510006.|Key Laboratory of Marine Resources and Coastal Engineering in Guangdong Province, Guangzhou, China, 510006.
authors.forename: Kedong
authors.initials: K
authors.lastname: Yin
mesh_terms: D001419:Bacteria / Q000302:isolation & purification / Q000821:virology; D018407:Bacterial Physiological Phenomena; D006723:Hong Kong; D056265:Microbial Interactions; D012623:Seawater / Q000382:microbiology; D018406:Virus Physiological Phenomena; D014871:Water Microbiology