Bioassay-based screening of myxobacteria producing antitumor secondary metabolites

Myxobacteria are gliding gram-negative bacteria and a class of prokaryote with complicated multicellular behaviors and morphogenesis. Reports show that myxobacteria generally produce large families of secondary metabolites with various bioactivities, such as antifungal and anti-tumor activities. In this paper, two strains producing metabolites with high anticancer bioactivity to 5 tumor cell lines were screened from over 370 isolated samples by adopting cell culturing technology and cell toxicity tests. The strains were identified as genus polyangium (Polyangium vitellinum and Sorangium cellulosum), named JSW103 and AHB125, based on the morphology of vegetative swarms, fruiting bodies, vegetative cells and myxospores. IC50 values of JSW103 to tumor cell lines B16 and SGC7901 were 0.2715 and 4.1924
g ml-1, respectively, while for AHB125 metabolites to tumor cell lines B16 and SGC7901, the values were 0.0082 and 0.036
g ml-1, respectively.