Microbial diversity of saline environments: searching for cytotoxic activities

AMB Express

Angela Cantillo¹  María Mercedes Zambrano¹  Freddy A. Ramos²  Susana Fiorentino³  Laura Yinneth Rojas³  Tito Sandoval³  Jorge Robles⁴  Carolina Díaz-Cárdenas⁵  Sandra Baena⁵ 

[1] Corporación Corpogen;Departamento de Química, Universidad Nacional de Colombia-Sede Bogotá;Grupo de Inmunobiología y Unidad de Investigación en Ciencias Biomédicas, Pontificia Universidad Javeriana;Grupo de Investigación Fitoquímica, Pontificia Universidad Javeriana;Unidad de Saneamiento y Biotecnología Ambiental, Departamento de Biología, Pontificia Universidad Javeriana;

关键词: Phylogenetic diversity;    Halophilic bacteria;    Cytotoxic activity;    Secondary metabolism;   

DOI  :  10.1186/s13568-017-0527-6

来源: DOAJ

【 摘 要 】

Abstract 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 IC50 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 IC50 < 6 μg mL−1. Other extracts with high levels of cytotoxic activity were obtained from Bacillus sp. (IC50 < 50 μg mL−1) which contained several compounds such as macrolactin L and A, 7-O-succinoylmacrolactin F and iturin. Shewanella chilikensis USBA 344 also showed high levels of cytotoxic activity against both cell lines in the crude extract: an IC50 < 15 μg mL−1 against the 4T1 cell line and an IC50 < 68 μg mL−1 against the MCF-7 cell line. Nesterenkonia sandarakina CG 35, which has an IC50 of 118 µg mL−1 against 4T1, is a producer of diketopiperazines and 1-acetyl-β-carboline. Also, Ornithinimicrobium kibberense CG 24, which has IC50 < 50 μg mL−1, was a producer of diketopiperazines and lagunamycin. Our study demonstrates that these saline environments are habitats of halophilic and halotolerant bacteria that have previously unreported cytotoxic activity.

【 授权许可】

Unknown