1. Efficient production of mutant phytase (phyA-7) derived from Selenomonas ruminantium using recombinant Escherichia coli in pilot scale.
- Author
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Chi-Wei Lan J, Chang CK, and Wu HS
- Subjects
- 6-Phytase genetics, Acetic Acid pharmacology, Bacterial Proteins genetics, Complex Mixtures metabolism, Escherichia coli drug effects, Escherichia coli genetics, Fermentation, Gene Expression, Pilot Projects, Promoter Regions, Genetic, Recombinant Proteins genetics, Recombinant Proteins metabolism, Selenomonas enzymology, 6-Phytase metabolism, Acetic Acid metabolism, Bacterial Proteins metabolism, Escherichia coli enzymology, Selenomonas chemistry
- Abstract
A mutant gene of rumen phytase (phyA-7) was cloned into pET23b(+) vector and expressed in the Escherichia coli BL21 under the control of the T7 promoter. The study of fermentation conditions includes the temperature impacts of mutant phytase expression, the effect of carbon supplements over induction stage, the inferences of acetic acid accumulation upon enzyme expression and the comparison of one-stage and two-stage operations in batch mode. The maximum value of phytase activity was reached 107.0 U mL(-1) at induction temperature of 30°C. Yeast extract supplement demonstrated a significant increase on both protein concentration and phytase activity. The acetic acid (2 g L(-1)) presented in the modified synthetic medium demonstrated a significant decrease on expressed phytase activity. A two-stage batch operation enhanced the level of phytase activity from 306 to 1204 U mL(-1) in the 20 L of fermentation scale. An overall 3.7-fold improvement in phytase yield (35,375.72-1,31,617.50 U g(-1) DCW) was achieved in the two-stage operation., (Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.)
- Published
- 2014
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