Medium optimization for submerged fermentative production of β-cyclodextrin glucosyltransferase by isolated novel alkalihalophilic Bacillus sp. NCIM 5799 using statistical approach

Abstract

Abstract β-cyclodextrin glucosyltransferase (β-CGTase) is an essential enzyme to catalyse the biotransformation of starch into β-cyclodextrins (β-CD). β-CD has widespread applications in the biomedical, pharmaceutical and food industries. The present study focused on β-CGTase production using an efficient natural microbial strain and statistical production optimization for enhanced production. The isolated organism Bacillus sp. NCIM 5799 was found to be 5 μm short bacilli under FE-SEM and alkalihalophilic in nature. The β-CGTase production was optimized using a combination of Plackett–Burman design (PBD) and Central Composite Design—Response Surface Methodology (CCD-RSM). On PBD screening Na2CO3, peptone and MgSO4.7H2O were found to be significant for optimal β-CGTase production, whereas the soluble starch and K2HPO4 concentrations were found to be nonsignificant for β-CGTase production. The significant factors obtained after PBD were further optimized using CCD-RSM design. Peptone was found to have a significant interaction effect with Na2CO3, and MgSO4·7H2O and Na2CO3 exhibited a significant effect on the production of CGTase. The production of β-CGTase was enhanced in the presence of peptone (3%) and Na2CO3 (0·8%). CGTase production obtained was 156·76 U/ml when optimized using CCD-RSM. The final optimized medium (RSM) shows 7·7- and 5·4-fold high productions as compared to un-optimized and one factor at a time production media.