Isolation and Screening for Prodigiosin Producing Serratia marcences from Different Sources

Abstract

Prodigiosin is a red bioactive pigment produced by several bacterial species, particularly Serratia marcescens. It has potential applications as a natural colorant and has been reported to exhibit antimicrobial, anticancer, and immunosuppressive properties. This study aimed to isolate and screen Serratia isolates from Kano State, Nigeria, for prodigiosin production. Samples were collected from multiple locations across the state. Red-pigmented isolates were screened on agar plates using a pigment-production screening method and identified by Gram staining and biochemical tests. Isolates were further characterized by 16S rRNA gene sequencing. Prodigiosin production was assessed by cultivating each isolate in nutrient broth and determining pigment concentration. Twenty red to red-orange bacterial isolates were recovered from the samples. Of these, three soil-derived isolates, designated DSSK 5, SSK 3, and SSK 7, produced the pigment. Sequence analysis indicated that SSK 3 shared 95.36% similarity with either Serratia marcescens strain KNU-AP16 or Serratia nematodiphila strain UMAGOD10. DSSK 5 showed 95.88% similarity to Serratia marcescens strain ICC-4, whereas SSK 7 showed 98.97% similarity to Serratia marcescens strain INS420. Under the tested culture conditions, SSK 3 produced the highest reported prodigiosin concentration (4.9 ± 0.157 mg/L), while DSSK 5 produced the lowest (2.76 ± 0.019 mg/L). These findings indicate that prodigiosin-producing Serratia can be recovered from local soils in Kano State and that pigment yield varies among isolates under the same culture conditions.