Optimization of amylase fermentation conditions by marine bacterium Bacillus sp.YP07 using response surface methodology

An amylase producing marine bacterium Bacillus sp.YP07 was isolated from the coastal water of Yangpu in Hainan.Plackett-Burman design and Response Surface Methodology(RSM) were used to optimize the production conditions of amylase.The results showed that the concentrations of peptone,yeast extract and NaCl were the most significant factors to influence amylase production.The optimal conditions were as followed: starch 5.00g/L,peptone 3.88g/L,yeast extract 3.97g/L,NaCl 37.69g/L,pH 7.0,rotation speed 180r/min,temperature 35℃ and fermentation time 48h.Under these conditions,the amylase activity was 665.4U/mL,which was increased by more than 4.3 folds compared with that before optimization.