Microbial diversity of saline environments: searching for cytotoxic activities

• Published in: AMB Express 2017-12, Vol.7 (1), p.223-16, Article 223
• Main Authors: Díaz-Cárdenas, Carolina, Cantillo, Angela, Rojas, Laura Yinneth, Sandoval, Tito, Fiorentino, Susana, Robles, Jorge, Ramos, Freddy A., Zambrano, María Mercedes, Baena, Sandra
• Format: Article
• Language: English
• Subjects: Adenocarcinoma; Bacillus; Biomedical and Life Sciences; Biotechnology; Chloroform; Cytotoxic activity; Cytotoxicity; Halophilic bacteria; Life Sciences; Microbial Genetics and Genomics; Microbiology; Microorganisms; Original; Original Article; Phylogenetic diversity; Saline environments; Salinity tolerance; Secondary metabolism; Strains (organisms); Tumor cell lines
• ISSN: 2191-0855; 2191-0855
• DOI: 10.1186/s13568-017-0527-6

In order to select halophilic microorganisms as a source of compounds with cytotoxic activities, a total of 135 bacterial strains were isolated from water and sediment samples collected from the Zipaquirá salt mine in the Colombian Andes. We determined the cytotoxic effects of 100 crude extracts from 54 selected organisms on the adherent murine mammary cell carcinoma 4T1 and human mammary adenocarcinoma MCF-7 cell lines. These extracts were obtained from strains of Isoptericola, Ornithinimicrobium, Janibacter, Nesterenkonia, Alkalibacterium, Bacillus, Halomonas, Chromohalobacter, Shewanella, Salipiger, Martellela, Oceanibaculum, Caenispirillum and Labrenzia . The extracts of 23 strains showed an IC 50 of less than 100 μg mL −1 . They were subsequently analyzed by LC/MS allowing dereplication of 20 compounds. The cytotoxic effect was related to a complex mixture of diketopiperazines present in many of the extracts analyzed. The greatest cytotoxic activity against both of the evaluated cell lines was obtained from the chloroform extract of Labrenzia aggregata USBA 371 which had an IC 50