Optimization of prodigiosin biosynthesis by Serratia marcescens using unconventional bioresources

Prodigiosin is a naturally occurring red pigment by Serratia marcescens and having enormous medicinal properties. Recently, there is a need to develop a high-throughput and economically feasible bioprocess for the production of prodigiosin. In order to find a cost-effective alternative to individual fatty acids as substrate in industries, we tried to study the effect of different fatty acid containing oil seed cakes of peanut, sesame, and mustard as sources of substrate. The present study screened waste and unconventional bioresources for the production of prodigiosin using S. marcescens ATCC 13880. Sources with high oil content were screened for maximum production of prodigiosin. Also, various parameters like temperature, pH, and nutrient precursors were screened and optimized for the production of prodigiosin.

Scaled-up of optimized media consisting of 4% peanut oil seed cake powder, 2% sucrose, pH 7.5, temperature 28 °C, and 72 h incubation time resulted in highest production of 15.5 g/L wet biomass and 0.9 g/L of dried prodigiosin. Further, UV scan of the pigment showed maximum absorbance at 538 nm which is physiological property of the pigment. Extraction and purification of the pigment at the commercial level using the chromatographic techniques and mass spectral analysis confirmed the presence of prodigiosin.

Using oil-extraction leftover wastes might help in the commercial and cost-effective production of prodigiosin.