title: Exploration of the antioxidant system and photosynthetic system of a marine algicidal Bacillus and its effect on four harmful algal bloom species.
abstract: A novel marine bacterium, strain B1, initially showed 96.4% algicidal activity against Phaeocystis globosa. Under this situation, 3 other harmful algal species (Skeletonema costatum, Heterosigma akashiwo, and Prorocentrum donghaiense) were chosen to study the algicidal effects of strain B1, and the algicidal activities were 91.4%, 90.7%, and 90.6%, respectively. To explore the algicidal mechanism of strain B1 on these 4 harmful algal species, the characteristics of the antioxidant system and photosynthetic system were studied. Sensitivity to strain B1 supernatant, enzyme activity, and gene expression varied with algal species, while the algicidal patterns were similar. Strain B1 supernatant increased malondialdehyde contents; decreased chlorophyll a contents; changed total antioxidant and superoxide dismutase activity; and restrained psbA, psbD, and rbcL genes expression, which eventually resulted in the algal cells death. The algicidal procedure was observed using field emission scanning electron microscopy, which indicated that algal cells were lysed and cellular substances were released. These findings suggested that the antioxidant and photosynthetic system of these 4 algal species was destroyed under strain B1 supernatant stress. This is the first report to explore and compare the mechanism of a marine Bacillus against harmful algal bloom species of covered 4 phyla.
authors.affiliation: a Key Laboratory of Water and Soil Pollution Control and Bioremediation of Guangdong Higher Education Institutes, School of Environment, Jinan University, Guangzhou 510632, People's Republic of China.|b Guangzhou Key Laboratory of Environmental Exposure and Health, School of Environment, Jinan University, Guangzhou 510632, People's Republic of China.
authors.forename: Shaoling
authors.initials: S
authors.lastname: Hou
authors.affiliation: a Key Laboratory of Water and Soil Pollution Control and Bioremediation of Guangdong Higher Education Institutes, School of Environment, Jinan University, Guangzhou 510632, People's Republic of China.|b Guangzhou Key Laboratory of Environmental Exposure and Health, School of Environment, Jinan University, Guangzhou 510632, People's Republic of China.
authors.forename: Wanjiao
authors.initials: W
authors.lastname: Shu
authors.affiliation: c Department of Chemistry, Jinan University, Guangzhou 510632, People's Republic of China.
authors.forename: Shuo
authors.initials: S
authors.lastname: Tan
authors.affiliation: a Key Laboratory of Water and Soil Pollution Control and Bioremediation of Guangdong Higher Education Institutes, School of Environment, Jinan University, Guangzhou 510632, People's Republic of China.|b Guangzhou Key Laboratory of Environmental Exposure and Health, School of Environment, Jinan University, Guangzhou 510632, People's Republic of China.
authors.forename: Ling
authors.initials: L
authors.lastname: Zhao
authors.affiliation: c Department of Chemistry, Jinan University, Guangzhou 510632, People's Republic of China.|d Research Center of Analytical Testing, Jinan University, Guangzhou 510632, People's Republic of China.
authors.forename: Pinghe
authors.initials: P
authors.lastname: Yin
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D001407:Bacillus / Q000378:metabolism*; D057097:Harmful Algal Bloom; D008315:Malondialdehyde / Q000032:analysis; D010788:Photosynthesis; D014871:Water Microbiology
chemical_list: D000975:Antioxidants; D008315:Malondialdehyde
keywords: Bacillus algicide; algicidal Bacillus; dommage morphologique; dommage oxydatif; expression génique; gene expression; harmful algal blooms; morphologic damage; oxidative damage; proliférations d’algues nuisibles