OPTIMIZED PRODIGIOSIN PRODUCTION BY SERRATIA MARCESCENS AND ITS ANTIMICROBIAL EFFECT

Abstract

Serratia marcescens commonly synthesize a red pigment known as prodigiosin. Prodigiosin is considered a promising pharmaceutical due to its documented properties of having antimicrobial, anticancer, and immunosuppressive effects. This investigation involved the isolation of Serratia marcescens, a bacterium capable of producing prodigiosin, from grey water samples collected in Nnamdi Azikiwe University Awka campus, Nigeria. The central composite design (CCD) of the experiment was applied to generate a set of 31 experimental combinations to study the optimal conditions for pigment production using nutrient broth supplemented with glucose as a fermentation medium. A regression model that described the relationship between the test variables for optimum prodigiosin yield was developed. The regression coefficient (R2) value of 72.48% implied adequate model fitness. The optimal conditions identified were 24 g/L glucose concentration, pH 7.2, 2.4 mL inoculum size, and 180 rpm agitation speed. A 4.25-fold increase in prodigiosin yield was recorded in optimized condition than in unoptimized condition. Antimicrobial activity against E. coli and Candida albicans shows that prodigiosin has significantly higher activity than the conventional antibiotics tested. Our results indicate that prodigiosin production by Serratia marcescens can be enhanced using statistical models, and the pigment can be an alternative to conventional antibiotics for treating microbial infections.

Keywords

• Prodigiosin
• Serratia marcescens
• Response surface
• Optimization
• antimicrobial