Bioproduction, characterization, and evaluation of the biological activities of prodigiosin from Serratia marcescens HMS

Prodigiosin is a bioactive red pigment with antimicrobial and anticancer properties, offering a natural substitute for synthetic colorants. A pigment-producing strain, Serratia marcescens HMS, was isolated from air and identified via 16S rRNA sequencing (GenBank Accession No. PP456732.1; 100% similarity). Acetone yielded the highest pigment extraction efficiency (4.54 mg/L). Optimal production (6.98 mg/L) occurred in LB medium (pH 7) at 30 °C under shaking conditions (150 rpm). Sweet potato peels served as an effective low-cost and sustainable agricultural waste substrate for extracellular pigment production. The purified pigment was confirmed as prodigiosin using TLC, HPLC, FTIR, and GC–MS (C20H25N3O; m/z 323). The pigment displayed antimicrobial activity against Bacillus subtilis (inhibition zone: 12 mm), cytotoxicity against HepG2 and MCF-7 cells (IC50: 61.12 ± 2.64 and 87.86 ± 4.18 μg/mL, respectively), and α-glucosidase inhibitory activity (IC50: 380.27 ± 8.15 μg/mL). These results establish S. marcescens HMS as an efficient prodigiosin producer and highlight the pigment’s potential for pharmaceutical and industrial applications.