A novel phytase gene appA from Buttiauxella sp. GC21 isolated from grass carp intestine

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• 作者：Pengjun Shi ; Huoqing Huang ; Yaru Wang ; Huiying Luo ; Bo Wu ; Kun Meng ; Peilong Yang ; Bin Yao
• 关键词：Buttiauxella sp. ; Grass carp ; Phytase ; Phytate
• 刊名：Aquaculture
• 出版年：2008
• 期刊代码：16_00448486
• 类别：abs
• 出版时间：31 March 2008
• 卷：275
• 期：1-4
• 页码：70-75
• 文件大小：1010 K

摘要

A novel phytase gene, appA, was isolated by degenerate PCR and genomic library screening from Buttiauxella sp. GC21, a bacterium isolated from grass carp intestine. The full-length gene consists of an open reading frame of 1341 bp and encodes 446 amino acids, including 33 amino acid residues of a putative signal peptide. Containing the active site of typical histidine acid phosphatases, the amino acid sequence shows maximum identity (71%) to PhyA from Obesumbacterium proteus. The gene encoding the mature phytase was expressed in Escherichia coli and the purified recombinant APPA had a specific activity for sodium phytate of 1180 U mg^{− 1} of protein. The optimum temperature was 55 °C and the optimum pH was 4.5. The K_m value was 0.36 mM, with a V_max of 1.39 mmol min^{− 1} mg^{− 1}. This is the first report to detect and isolate a phytase from Buttiauxella sp.