Expression of recombinant phytase of Bacillus subtilis E20 in Escherichia coli HMS 174 and improving the growth performance of white shrimp, Litopenaeus vannamei, juveniles by using phytase-pretreated soybean meal-containing diet

摘要

To produce a thermostable and neutral phytase (phy) of Bacillus subtilis E20 in Escherichia coli HMS174 and evaluate its efficiency in improving growth performance. The phy C of B.subtilis E20 was expressed in E.coli HMS 174, and then the 42-kDa recombinant phy C was purified by Ni-NAT and analysed by SDSPAGE. The recombinant phy C had optimal ranges of pH of 6 similar to 7 and temperature of 50 similar to 60 degrees C. A thermostability analysis showed that the enzyme is a thermostable phytase, and around 33% of residual activity was detected after being incubated at 90 similar to 100 degrees C for 10min. The recombinant phy C-pretreated soybean meal for feed preparation improved white shrimp, Litopenaeus vannamei, growth and feed efficiency. Overall, the neutral and thermostable phy C is suitable for aquafeed, and it is able to improve the nutritional utilization, resulting in enhanced shrimp growth and reduced feed costs.