A novel phytase with preferable characteristics from Yersinia intermedia.
A Yersinia intermedia strain producing phytase was isolated from glacier soil. The phytase gene, appA, was isolated by degenerate PCR and TAIL-PCR. The full-length fragment contained 2354bp with a 1326-bp open reading frame encoding 441 amino acids. APPA contained the active site RHGXRXP and HD sequence motifs that are typical of histidine acid phosphatases. To our knowledge, this is the first report of the detection of phytase activity and cloning of the relevant gene from Y. intermedia. The gene was overexpressed in Pichia pastoris, and the purified recombinant APPA had a specific activity for sodium phytate of 3960U/mg, which is higher than that of the Citrobacter braakii phytase (previously the highest specific activity known). Recombinant APPA had high activity from pH 2 to 6 (optimum 4.5) and optimal temperature of 55 degrees C; the enzyme was resistant to pepsin and trypsin. These characteristics suggest that APPA may be highly suitable for use in the feed industry.
Huang
Huoqing
H
Department of Microbial Engineering, Feed Research Institute, Chinese Academy of Agricultural Sciences, PR China.
Luo
Huiying
H
Yang
Peilong
P
Meng
Kun
K
Wang
Yaru
Y
Yuan
Tiezheng
T
Bai
Yingguo
Y
Yao
Bin
B
D010832:6-Phytase / Q000737:chemistry*; D000595:Amino Acid Sequence; D008969:Molecular Sequence Data; D013045:Species Specificity; D015007:Yersinia / Q000145:classification* / Q000201:enzymology*
D010832:6-Phytase