title: Screening of microorganisms from Antarctic surface water and cytotoxicity metabolites from Antarctic microorganisms.
abstract: The Antarctic is a potentially important library of microbial resources and new bioactive substances. In this study, microorganisms were isolated from surface water samples collected from different sites of the Antarctic. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay-based cytotoxicity-tracking method was used to identify Antarctic marine microorganism resources for antitumor lead compounds. The results showed that a total of 129 Antarctic microorganism strains were isolated. Twelve strains showed potent cytotoxic activities, among which a Gram-negative, rod-shaped bacterium, designated as N11-8 was further studied. Phylogenetic analysis based on 16S rRNA gene sequence showed that N11-8 belongs to the genus Bacillus. Fermented active products of N11-8 with molecular weights of 1-30 kDa had higher inhibitory effects on different cancaer cells, such as BEL-7402 human hepatocellular carcinoma cells, U251 human glioma cells, RKO human colon carcinoma cells, A549 human lung carcinoma cells, and MCF-7 human breast carcinoma cells. However, they displayed lower cytotoxicity against HFL1 human normal fibroblast lung cells. However, they displayed lower cytotoxicity against HFL1 human normal fibroblast lung cells. Microscopic observations showed that the fermented active products have inhibitory activity on BEL-7402 cells similar to that of mitomycin C. Further studies indicated that the fermented active products have high pH and high thermal stability. In conclusion, most strains isolated in this study may be developed as promising sources for the discovery of antitumor bioactive substances. The fermented active products of Antarctic marine Bacillus sp. N11- 8 are expected to be applied in the prevention and treatment of cancer.
authors.affiliation: Key Laboratory for Sustainable Utilization of Marine Fisheries Resources Ministry of Agriculture Yellow Sea Fisheries Research Institute Chinese Academy of Fishery Sciences Qingdao 266071 China.
authors.forename: Lanhong
authors.initials: L
authors.lastname: Zheng
authors.affiliation: Key Laboratory for Sustainable Utilization of Marine Fisheries Resources Ministry of Agriculture Yellow Sea Fisheries Research Institute Chinese Academy of Fishery Sciences Qingdao 266071 China.
authors.forename: Kangli
authors.initials: K
authors.lastname: Yang
authors.affiliation: Medical College Qingdao University Qingdao 266021 China.
authors.forename: Jia
authors.initials: J
authors.lastname: Liu
authors.affiliation: Key Laboratory for Sustainable Utilization of Marine Fisheries Resources Ministry of Agriculture Yellow Sea Fisheries Research Institute Chinese Academy of Fishery Sciences Qingdao 266071 China.
authors.forename: Mi
authors.initials: M
authors.lastname: Sun
authors.affiliation: Key Laboratory for Sustainable Utilization of Marine Fisheries Resources Ministry of Agriculture Yellow Sea Fisheries Research Institute Chinese Academy of Fishery Sciences Qingdao 266071 China.
authors.forename: Jiancheng
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Key Laboratory for Sustainable Utilization of Marine Fisheries Resources Ministry of Agriculture Yellow Sea Fisheries Research Institute Chinese Academy of Fishery Sciences Qingdao 266071 China.
authors.forename: Mei
authors.initials: M
authors.lastname: Lv
authors.affiliation: Key Laboratory for Sustainable Utilization of Marine Fisheries Resources Ministry of Agriculture Yellow Sea Fisheries Research Institute Chinese Academy of Fishery Sciences Qingdao 266071 China.
authors.forename: Daole
authors.initials: D
authors.lastname: Kang
authors.affiliation: Key Laboratory for Sustainable Utilization of Marine Fisheries Resources Ministry of Agriculture Yellow Sea Fisheries Research Institute Chinese Academy of Fishery Sciences Qingdao 266071 China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Key Laboratory for Sustainable Utilization of Marine Fisheries Resources Ministry of Agriculture Yellow Sea Fisheries Research Institute Chinese Academy of Fishery Sciences Qingdao 266071 China.
authors.forename: Mengxin
authors.initials: M
authors.lastname: Xing
authors.affiliation: Key Laboratory for Sustainable Utilization of Marine Fisheries Resources Ministry of Agriculture Yellow Sea Fisheries Research Institute Chinese Academy of Fishery Sciences Qingdao 266071 China.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Li
keywords: Antarctic surface water; MTT method; cytotoxicity; fermented active products; microorganism screening