Optimization and comparative studies on activities of β-mannanase from newly isolated fungal and its mutant

Khattab, Om K.H.; Ismail, Siham A.; Abosereh, Nivien A.; Abo-Elnasr, Amany A.; Nour, Shaimaa A.; Hashem, Amal M.

doi:10.4103/epj.epj_48_19

Optimization and comparative studies on activities of β-mannanase from newly isolated fungal and its mutant

Authors

Abstract

Background and objective
β-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 β-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 β-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 β-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 β-mannanase for 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 150 GY β-mannanase from 219 to 296 IU/ml by applying Plackett–Burman design and increased the level of β-mannanase biosynthesis to 351 IU/ml. Primary characterization of β-mannanase produced by and 150 GY proved that they are almost the same, except in a little shift to higher value (5°C) in optimum temperature.

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