高效植酸盐降解细菌水拉恩氏菌JZ-GX1的植酸酶特性研究

摘要

The efficient phytate-degrading rhizobacteria Rahnella aquatilis JZ-GX1 were used as the research object to study the locating expression of phytase secreted by JZ-GX1. The results show as follews:there were significantly differences among phytase specific activities of different parts of the bacteria culture incubated for 48 hours. the phytase specific activities of extracellular supernatant, intercellular substance and inside cell were 2.5037 U/mg, 0.0015 U/mg, 0.0002 U/mg respectively, which indicated that the phyratse secreted by JZ-GX1 was a kind of extracellular enzyme. Learned from the studies on enzymology characteristics of phytase of JZ-GX1, it showed that the phytase secreted by JZ-GX1 had excellent resistance to acid, but not alkali resistance, its optimal pH value was about 5.5, optimum reaction temperature was about 37℃, when temperature was less than 50 ℃, the phytase had good thermal stability. The results of this study could provide a useful reference for using R. aquatilis JZ-GX1 as bio-fertilizer in agricultural production in the future.%以高效植酸盐降解细菌水拉恩氏菌（Rahnella aquatilis）JZ-GX1为研究对象，对其分泌的植酸酶在细胞内的定域进行研究，结果表明：在该菌48 h的培养物中，菌株细胞不同部位的植酸酶比活力存在极显著差异，分别为：胞外上清液2.5037 U/mg，胞间质0.0015 U/mg，胞内0.0002 U/mg，说明JZ-GX1菌株所产植酸酶为胞外酶；通过研究pH值和温度对该菌分泌的胞外植酸酶活性的影响表明，JZ-GX1菌株所产植酸酶为酸性植酸酶，最适pH值为5.5，具有一定的耐酸性，但不耐碱；最适温度为37℃，当温度小于50℃时，该酶具有良好的热稳定性。本研究为水拉恩氏菌JZ-GX1将来作为微生物菌肥应用于农林业生产，提供了有价值的参考依据。