Production of extra cellular enzymes by microbial strains in molasses and additives supplemented fermentation media

摘要

This work investigates the use of molasses (a cheap substrate) together with additives in fermentation medium to produce extra cellular protease, amylase and lipase, with the aid of Aspergillus oryzae and Bacillus subtilis. The concentration of molasses (0.1 – 1.0%) used for enzyme production by A. oryzae significantly influenced the extracellular lipase, amylase and protease biosynthesis/ secretion. The highest extracellular enzyme activities were found at 96 h of processing (72, 52 and 65 U/ml for lipase, amylase and protease, respectively). As additives, two different carbon sources: Avena sativa and Cicer arietinum were tested for production of extracellular enzymes by A. oryzae. Among the different concentrations of A. sativa, high enzyme activity (61, 83 and 121 U/ml, respectively for lipase, amylase and protease) was noted at concentration of 2.5 g/L. For another additive, C. arietinum, highest extracellular enzyme activity was found at 96 h (71; 61, 80 U/ml for lipase, amylase and protease). In this study, it is concluded that the production of extracellular enzyme using molasses with additives had maximum value compared to using molasses alone in 96 h fermentation by Aspergillus oryzae.