Optimisation of Culture media through Response surface methodology to improve Antioxidant activity of E. coli

Antioxidants play a significant role in oxidative stress management and health protection. One variable at a time response surface methodology (RSM) was used to formulate different composition of media to increase the antioxidant property of selected microorganism (Escherichia coli MTCC no. 40). 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assays was used to measure antioxidant activity of selected microorganism. The reduction potentiality of DPPH radical was determined by the DPPH% antioxidant or scavenging activity of the solution. In the present study, we have measured antioxidant activity of both intracellular and extracellular metabolites in dry and wet extracellular metabolites in supernatant respectively. In DPPH assay, extracellular metabolites showed better antioxidant potential in comparison with the reference compound. The comparison was based on antioxidant activity in different responses (number 1–16) for both dry and wet biomass. According to the results maximum DPPH % antioxidant or scavenging activity was showed by response 9 (wet biomass) and response 6 (dry biomass) that is 24.8447 and 35.0142 respectively in comparison to standard (4.4636). Hence, response surface methodology is used in bioprocess technology to optimize the medium components which is the primary step involved to enhance the antioxidant activity of particular microorganism.