초록
<P><B>Abstract</B></P><P>The <I>Streptomyces lonarensis</I> strain NCL 716 hydrolyses starch to produce a mixture of maltotriose (G3) and maltotetraose (G4) along with maltose (G2). The objective of the present work was to determine an optimum cost effective media composition for the production of α‐amylase from this strain. The most influential factor was found to be starch while the least influential factor found was peptone by Plackett–Burman method. Peptone amount was kept constant throughout the fermentation. Peptone, which is one of the expensive media components was used at a concentration of 1 g/L, which made the optimum media composition cost effective. A support vector regression‐based process model was developed for approximating the non‐linear relationship between the fermentation operating variables and the α‐amylase yield. Multicanonical Jump Walk Annealing, a stochastic optimization technique is used to obtain optimal operating variables to maximize amylase yield. The maximum amylase activity thus obtained was in good agreement with the experimental values at the optimized levels. The optimum media composition obtained by this method was: yeast extract: 4.53 g/L, starch: 20.246 g/L, K<SUB>2</SUB>HPO<SUB>4</SUB>: 0.0827%, MgSO<SUB>4</SUB>: 0.15%, peptone: 1 g/L. A maximum enzyme activity of 297 U/mL, which was achieved using the above approaches compares well with the activity of reported amylases producing maltooligosaccharides.</P>