Identification and enhanced production of prodigiosin isoform pigment from Serratia marcescens N10612

• A strain named Serratia marcescens N10612 was isolated from soil culture.
• A series of nutrition tests were performed for the production of PIPs by this strain.
• Optimal production of PIPs was carried out through statistical experiment designs.
• Separation and identification of PIPs were carried out via high resolution MS and MNR.
• The PIPs are identified as shorter carbon chain isoform pigments.

Serratia marcescens N10612, isolated from soil culture, was found to produce the bio-active prodigiosin isoform pigment (PIP) through nutrition tests. The complex medium consisting of sucrose, peptone and yeast extract was found to be the best composition for PIP production. The optimization of PIP production was carried out by using statistical experiment designs. The optimal concentrations of medium were yeast extract 5.6 g/L, peptone 6.9 g/L, sucrose 31.6 g/L and NaCl 1.0 g/L. Under the optimal conditions, the predicted production of PIP was 1307 mg/L, while the experimental value was 1303 mg/L. Further identification by high resolution mass spectrometry and MNR revealed that the PIP products were prodigiosin and its isoforms. The PIP produced by this strain belongs to shorter carbon chains isoforms (15, 17, 18, 20-C) mentioned in the report. These PIPs are expected to have bioactive functions in medical and clinical applications.