Quality by design: Optimization of media components and factors affecting biosynthesis of copper nanoparticles by Bacillus cereus

Copper is useful in various ways for wellbeing and copper nanoparticles (CuNps) find various applications in electronics, healthcare, etc. Microbial synthesis of metal nanoparticles is a nanobiotechnology approach which is intersection of nanotechnology with biology. Here, we attempted to optimize production of biosynthesized CuNps from a copper resistant strain of Bacillus cereus, using quality by design approach. Media components were optimized by Placket Burman design for 11 media components using 12 individual runs and measuring three responses variables viz., optical density, dry cell weight and extracellular protein concentration. Various factors, which affect biochemical process of biosynthesis, were optimized by central composite design using 32 runs and measuring three responses variable viz., surface plasmon resonance, particle size and polydispersity index. Factorial models were optimized by selecting those factors which have maximum effect on response. The obtained results were statistically analyzed by ANOVA. Among the components of media, dextrose, peptone, yeast extract and copper sulphate had significant (p<0_05) effect on each responses. Temperature, filtrate concentration and copper ion concentration were found to have significant (p < 0_05) effect on biosynthesis of CuNps using Bacillus cereus.