ABSTRACT

 

Microbial biochromes are aesthetically alluring secondary metabolites that also display multifaceted applications. Prodigiosin is one such, pink to red, environmentally safe, biochrome produced by certain species of genera Serratia, Pseudomonas and Vibrio. It has found applications in several industries from textile to therapeutics. Currently, as per consumer demand for natural products, replacing synthetic pigments with biochromes like Prodigiosin can lead to several sustainable and long-term environmental benefits. However, Prodigiosin production faces concerns about economic viability and low yields. Moreover, most optimization studies focus on S. marcescens strains, overlooking the resource of S. rubidaea, which also holds prodigiosin production candidature. Hence, the present study aims at identifying and comparing key physical and chemical parameters, leading to prodigiosin yields using the one factor at a time approach (OFAT), in previously isolated S. marcescens and S. rubidaea. Optimization of physical parameters like pH, temperature  and incubation time, showed significantly higher yields at pH 6, 28°C and 96 hrs for both isolates. On comparing the chemical factors, the most significant carbon sources for S. marcescens and S. rubidaea were glycerol and glucose respectively, while yeast extract was the most effective nitrogen source for both. On studying the effect of supplements, FeSO4 and proline were found to be most effective for both the isolates. Considering all the effective factors, a production medium was designed which gave a 2.61-fold and 2.44-fold increase in prodigiosin yield for S. marcescens and S. rubidaea, respectively. 

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Keywords   Biochrome, Prodigiosin, Serratia marcescens, Serratia rubidaea, OFAT.