Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.
Curr Microbiol. 2011 Nov;63(5):408-15. doi: 10.1007/s00284-011-9995-0. Epub 2011 Aug 19.
Microbial phytases play a major role in the mineralization of organic phosphorous, especially in symbiotic plants and animals. In this study, we identified two types of phytases in Serratia sp. TN49 that was harbored in the gut of Batocera horsfieldi (Coleoptera) larvae. The two phytases, an acidic histidine acid phosphatase (PhyH49) and an alkaline β-propeller phytase (PhyB49), shared low identities with known phytases (61% at most). PhyH49 and PhyB49 produced in Escherichia coli exhibited maximal activities at pH 5.0 (60°C) and pH 7.5-8.0 (45°C), respectively, and are complementary in phytate degradation over the pH range 2.0-9.0. Serratia sp. TN49 harboring both PhyH49 and PhyB49 might make it more adaptive to environment change, corresponding to the evolution trend of microorganism.
微生物植酸酶在有机磷的矿化中起着重要作用，特别是在共生植物和动物中。在本研究中，我们在鞘翅目幼虫（Coleoptera）肠道中发现的沙雷氏菌（Serratia sp.）TN49 中鉴定出两种植酸酶，一种是酸性组氨酸酸性磷酸酶（PhyH49），另一种是碱性β-螺旋桨植酸酶（PhyB49）。这两种植酸酶与已知的植酸酶的同源性最低（最高为 61%）。在大肠杆菌中表达的 PhyH49 和 PhyB49 在 pH5.0（60°C）和 pH7.5-8.0（45°C）下表现出最大活性，并且在 pH2.0-9.0 范围内在植酸盐降解方面互补。同时含有 PhyH49 和 PhyB49 的沙雷氏菌（Serratia sp.）TN49 可能使其更适应环境变化，这与微生物的进化趋势相对应。
