Downstream Process Development for Extraction of Prodigiosin: Statistical Optimization, Kinetics, and Biochemical Characterization.

Prodigiosin is natural red colourant derived from Serratia marcescens. However, the high cost of prodigiosin restricts its use in food and pharmaceutical industries, which can be addressed with the design of a suitable extraction procedure. Therefore, the present study aims to use Taguchi methodology to optimize various process parameters during ultrasound-assisted extraction (UAE) to get a higher prodigiosin extraction yield. The most significant contribution comes from the solid-to-liquid ratio (36.66%), followed by sonication of duty cycle (34.82%), medium pH (15.7%), and acoustic intensity (12.82%). The Taguchi technique predicts the highest optimal yield using the solid-liquid ratio (0.3 g/mL), duty cycle sonication (75%), acoustic intensity (12.5 w/cm2), and medium pH (3) as parameters. When the extraction conditions were optimized, the yield of prodigiosin increased by 4166.89 mg/L. In the future, the above extraction conditions determined using Taguchi approach will be applied for large-scale extraction of prodigiosin. Finally, a second-order kinetic model is used to suit the batch extraction investigation and the second-order rate constant (k) has a value of 4 × 10-5 L/mg/min. In the future, the rate constant, which is reported for the first time, will be used to create a batch extractor for commercial extraction of prodigiosin. Prodigiosin has also been shown to have substantial antioxidant and scavenging properties, which increase in a dose-dependent way with prodigiosin concentration. Because of its antioxidant and scavenging properties, prodigiosin can be used as food additives or pharmaceutical ingredients in industries.