Michelsen Charlotte F, Jensen Helle, Venditto Vincent J, Hennessy Rosanna C, Stougaard Peter
Department of Systems Biology, Technical University of Denmark, Kgs. Lyngby, Denmark.
Department of Microbiology and Immunology, University of California, San Francisco, CA, United States.
PeerJ. 2015 Dec 3;3:e1476. doi: 10.7717/peerj.1476. eCollection 2015.
Background. Bioactive microbial metabolites provide a successful source of novel compounds with pharmaceutical potentials. The bacterium Pseudomonas sp. In5 is a biocontrol strain isolated from a plant disease suppressive soil in Greenland, which produces two antimicrobial nonribosomal peptides (NRPs), nunapeptin and nunamycin. Methods. In this study, we used in vitro antimicrobial and anticancer bioassays to evaluate the potential bioactivities of both a crude extract derived from Pseudomonas sp. In5 and NRPs purified from the crude extract. Results. We verified that the crude extract derived from Pseudomonas sp. In5 showed suppressive activity against the basidiomycete Rhizoctonia solani by inducing a mitochondrial stress-response. Furthermore, we confirmed suppressive activity against the oomycete Pythium aphanidermatum by the Pseudomonas sp. In5 crude extract, and that the purified nunamycin and nunapeptin displayed distinct antimicrobial activities. In addition to the antimicrobial activity, we found that treatment of the cancer cell lines, Jurkat T-cells, Granta cells, and melanoma cells, with the Pseudomonas sp. In5 crude extract increased staining with the apoptotic marker Annexin V while no staining of healthy normal cells, i.e., naïve or activated CD4 T-cells, was observed. Treatment with either of the NRPs alone did not increase Annexin V staining of the Jurkat T-cells, despite individually showing robust antimicrobial activity, whereas an anticancer activity was detected when nunamycin and nunapeptin were used in combination. Discussion. Our results suggest that the bioactivity of a crude extract derived from Pseudomonas sp. In5 involves the presence of both nunamycin and nunapeptin and highlight the possibility of synergy between multiple microbial metabolites.
背景。具有生物活性的微生物代谢产物是具有药物潜力的新型化合物的成功来源。假单胞菌属In5是从格陵兰岛的一种植物病害抑制性土壤中分离出的一种生物防治菌株，它能产生两种抗菌非核糖体肽（NRP），即努纳肽和努纳霉素。方法。在本研究中，我们使用体外抗菌和抗癌生物测定法来评估源自假单胞菌属In5的粗提物以及从粗提物中纯化的NRP的潜在生物活性。结果。我们证实，源自假单胞菌属In5的粗提物通过诱导线粒体应激反应，对担子菌立枯丝核菌具有抑制活性。此外，我们确认了假单胞菌属In5粗提物对卵菌瓜果腐霉具有抑制活性，并且纯化的努纳霉素和努纳肽表现出不同的抗菌活性。除了抗菌活性外，我们发现用假单胞菌属In5粗提物处理癌细胞系，即Jurkat T细胞、格兰塔细胞和黑色素瘤细胞，会增加凋亡标志物膜联蛋白V的染色，而未观察到健康正常细胞（即未活化或活化的CD4 T细胞）的染色。单独使用任何一种NRP处理均未增加Jurkat T细胞的膜联蛋白V染色，尽管它们各自都显示出强大的抗菌活性，而当努纳霉素和努纳肽联合使用时则检测到抗癌活性。讨论。我们的结果表明，源自假单胞菌属In5的粗提物的生物活性涉及努纳霉素和努纳肽的共同存在，并突出了多种微生物代谢产物之间协同作用的可能性。
