Optimization And Comparative Studies On Activities Of Beta-Mannanase From Newly Isolated Fungal And Its Mutant

Background and objective beta-Mannanase has potential industrial applications in pharmaceutical field, bioethanol production, coffee extraction, food and feed technology, etc. So finding a new and promising enzyme source is a very important issue. The aim of this study was to improve the biosynthesis of beta-mannanase by different techniques, such as mutation and optimization of the culture parameters. Materials and methods Five fungal isolates were tested for the production of beta-mannanase. Enzyme activity, protein content, and specific activity were determined. The most potent isolated microorganism and its mutant were identified by using Transmission Electron Microscopy and 18SrDNA sequencing and phylogenetic analysis. Ultraviolet and gamma rays were used. Optimization studies were done to maximize enzyme production from the most potent microorganism and its highly productive and stable mutant, including culture conditions and medium compositions, and statistical optimization was also carried out. Primary characterization of beta-mannanase was studied. Results and conclusion In our research, we found a stable mutant strain obtained by using gamma radiation at 150 GY. The first step of the fermentation, optimized by one-factor-at-a-time technique, increased the biosynthesis of beta-mannanase for Penicillium citrinium 150 GY from 65.9 to 219 IU/ml compared with the wild strain, which increased from 16.82 to 26.5 IU/ml. Statistical optimization improved P. citrinium 150 GY beta-mannanase from 219 to 296 IU/ml by applying Plackett-Burman design and increased the level of beta-mannanase biosynthesis to 351 IU/ml. Primary characterization of beta-mannanase produced by P. citrinium and P. citrinium 150 GY proved that they are almost the same, except in a little shift to higher value (5 degrees C) in optimum temperature.