Improving thermostability of Aspergillus niger phytase by elongation mutation.
- Author:
Hui CHEN
1
;
Hong-Ning WANG
;
Wan-Shen YANG
;
Hai-Xia ZHAO
;
Qi WU
;
Zhi SHAN
Author Information
1. College of Life & Science, Sichuan Agriculture University, Ya' an, Sichuan 625014.
- Publication Type:Journal Article
- MeSH:
6-Phytase;
biosynthesis;
genetics;
Amino Acid Sequence;
Aspergillus niger;
enzymology;
genetics;
Enzyme Stability;
genetics;
Escherichia coli;
enzymology;
genetics;
Fungal Proteins;
biosynthesis;
genetics;
Hot Temperature;
Molecular Sequence Data;
Mutation
- From:
Chinese Journal of Biotechnology
2005;21(6):983-987
- CountryChina
- Language:Chinese
-
Abstract:
The phytase gene phyA(m) from Aspergillus niger N25 was recombined into E. coli expression vector pET-30b(+). Recombined at expression vectors pET30b-FphyA(m) was served as a template to amplify phytase gene, and the PCR product named elongation mutation gene phyA(e) was expanded with a 13 amino acid sequence from pET-30b-FphyA(m) vector at C-terminal of phytase gene phyA(m). Furthermore, phyA(e) gene was recombined into expression vector pPIC9k and expressed in Pichia pastoris. The comparison experiment of mutant phytase PP-NP0 with wild-type phytase PP-NP(m)-8 showed that: the optimum temperature of PP-NPe was increased by 3 degrees C, and its thermostability was increased by 21% when it was exposed to 10 min at 75 degrees C. Its effective reaction pH range with catalysis efficiency above 70% was pH 4.6 - pH 6.6, and wider 0.4 pH value than that of wild-type phytase.
