RESUMO
Microbial inulinases have a great potential for industrial use in the production of fructose from inulin. Optimization of the growth parameters of the microbes is essential to obtain inulinase in sufficient quantity. The present work aimed to obtain inulinase from natural strains isolated from sugarcane fields and to optimize its growth parameters. In a total of ten isolates, four organisms Bacillus subtilis, Lactobacillus casei, Pseudomonas aeruginosa, and Achromobacter sp. were identified as efficient inulinase producers. The optimum temperature and pH of these organisms were found to be 40°C and pH 5 respectively. Inulin was observed to be the suitable carbon source for these organisms. The molecular weight of this enzyme was estimated at 45 KDa using SDS-PAGE. On thin layer chromatography inulin hydrolysis showed mono and disaccharides as the main end products. The highest enzyme activity was obtained from Achromobacter spp. of 333 U/L at 22nd hour which showed exo-inulinase type.