Effect of Amino Acid Supplementation on Prodigiosin and its Derivatives Production Using Agro-Waste as Potential Substrate

The food and beverage industries often utilize synthetic colors to enhance aesthetics, despite concerns about their potential health impacts. Consequently, there is a demand for alternative colors; however, the cultivation of non-toxic natural colors proves to be expensive. This study aims to increase the production of prodigiosin, a promising food color, utilizing pigment-producing microorganisms and agro-industrial waste as a substrate through solid-state fermentation technology. The research begins with screening suitable substrates, including wheat bran powder and rice bran, and orange peel powder, along with strains such as Serratia marcescens bhu prodig and Serratia nematodiphilia (NCIM 5606). Subsequently, pigment production is optimized through amino acid supplementation, particularly focusing on sulfur-containing amino acids (methionine, cysteine, and cystine) and aromatic amino acids (tryptophan and tyrosine). Various analytical techniques, including UV-Visiblspectrophotometry, NMR, FTIR, HRMS, and ESI–MS, are employed to characterize the produced pigment. The findings underscore wheat bran powder as an excellent substrate for pigment production, especially with the strain Serratia nematodiphilia (NCIM 5606). Remarkably, tyrosine emerges as the most effective supplement for enhancing pigment yield, followed by cysteine, cystine, and methionine, with a concentration of 0.125 g/L. Additionally, the pigment obtained contains prodigiosin and its derivatives, with molecular weights of 323.19 Da, 309.18 Da, and 351.23 Da.