Brown sugar as a low-cost medium for the production of prodigiosin by locally isolated Serratia marcescens UTM1

• Brown sugar was used as an alternative growth medium for Serratia marcescens UTM1.
• Furfural in brown sugar and culture conditions affected the pigment production.
• LC-MS, FTIR, NMR, hue and chroma values clearly identified the pigment as prodigiosin.

Interest in bacterial pigments such as prodigiosin is growing among researchers due to their antibacterial, antifungal, antiproliferative and immunosuppressive properties. However, commercial application of bacterial-based pigments such as prodigiosin is limited due to the high production cost, which is partly caused by the expensive growth medium. This study reports on the use of brown sugar for the growth of a locally isolated, red-pigment (prodigiosin)-producing bacterium, i.e. Serratia marcescens UTM1. Factors affecting prodigiosin production – notably culture conditions and the effect of lactose and L- tryptophan supplementation – were evaluated in both shake-flask and 5-l bioreactor conditions. The use of optimized conditions resulted in a high prodigiosin yield of ∼8000 mg l−1. The TLC and column chromatography-purified fraction was confirmed as prodigiosin using FTIR, LC-MS and NMR. This study demonstrates the feasibility of using brown sugar as a potential cheap growth medium for large-scale cultivation of prodigiosin using locally isolated S. marcescens UTM1.