Characterisation and evaluation of anticancer, antimicrobial and antioxidant activity of the pigment from Pyxidicoccus sp. S252

Abstract

Myxobacteria, a group of δ-proteobacteria, are known to be prolific producers of bioactive secondary metabolites. Pyxidicoccus sp. S252, a myxobacterial strain, produces an orange pigment. The pigment was extracted from the cells, and its bioactive potential was evaluated. The pigment extract inhibited Gram-positive bacteria and fungi (Alternaria sp. and Fusarium sp.) and exhibited antioxidant properties. The methanol extract of the pigment inhibited human osteosarcoma cells in vitro, with an IC50 of 87 µg/mL against MG-63 cells. The active fraction of the pigment implicated in antimicrobial activity was identified as a flexirubin-type pigment.