366013 Bioprocess Development of Microbial Enzymes with Outstanding Properties: An Egyptian Extremophiles Platform

Wednesday, November 19, 2014: 3:15 PM
207 (Hilton Atlanta)
Yasser R. Abdel-Fattah Sr.1,2, Hesham El-Enshasy Sr.3 and Mahmoud Sakr Sr.1, (1)Ministry of Scientific Research, Cairo, Egypt, (2)Bioprocess Development Dept., Genetic Engineering and Biotechnology Research Institute, Alexandria, Egypt, (3)Institute of Bioproduct Development, Universiti Teknologi Malaysia, Johor Bahru, Malaysia

Over two decades, researchers of Bioprocess Development Dept., Genetic Engineering and Biotechnology Research Institute have mastered the bioprocess development for the production of microbial enzymes with special preferences to extremophiles with the aim to establish an extremophiles' platform.

Within this context, we were able to define production medium to maximize the production of thermostable lipase and esterase by Geobacillus thermoleovorans YN with the aid of statistical-mathematical approaches that led to increase the productivity by 3 folds. The responsible gene for the production of this enzyme was identified and cloned into E.coli overexpression host and the enzyme was purified and well characterized. Both enzymes were most active at pH ∼9.5 and remarkably stable at pH 5 and 10.5. Temperature optima and stabilities (up to 70 °C) of both enzymes as well as their reaction kinetics and substrate spectra were determined.

In other work, we succeeded to optimize the production of alkaline protease from Bacillus pseudofirmus Mn6 in 15 L pilot plant bioreactor that lead to increase the productivity more than 10 folds initial activity under controlled PO2 and pH.

The production and purification of thermostable amylase from Bacillus licheniformis AI20 was also studied. Response Surface Methodology (RSM) was adopted to acquire the best process conditions among the selected variables, where a three-level Box-Behnken design was employed to create a polynomial quadratic model correlating the relationship between the three variables and 𝛼-amylase activity. The predicted optimum 𝛼-amylase activity was 384 U/mL/min, which is two folds more than the basal medium conditions. On enzyme level, the estimated molecular mass was 55 kDa and the 𝛼-amylase had an optimal temperature and pH of 60–80 Cand 6–7.5, respectively. The enzyme showed great stability against different solvents.


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