Singh Bijender, Satyanarayana T
Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India.
Bioresour Technol. 2008 May;99(8):2824-30. doi: 10.1016/j.biortech.2007.06.010. Epub 2007 Aug 2.
Phytase production by a thermophilic mould Sporotrichum thermophile Apinis was investigated in solid state fermentation (SSF) using sesame oil cake as the substrate. Scanning electron microscopy of the fermented sesame oil cake revealed a dense growth of the mould with abundant conidia. Glucose, ammonium sulphate and incubation period were identified as the most significant factors by Plackett-Burman design. The optimum values of the critical components determined by central composite design of response surface methodology for the maximum phytase production were glucose 3%, ammonium sulphate 0.5% and incubation period 120 h. An overall 2.6-fold improvement in phytase production was achieved due to optimization. Highest enzyme production (348.76 U/g DMR) was attained at a substrate bed depth of 1.5 cm in enamel coated metallic trays. The enzyme liberated inorganic phosphate from wheat flour and soymilk with concomitant dephytinization and liberation of soluble inorganic phosphate.
以芝麻油饼为底物,在固态发酵(SSF)中研究了嗜热霉菌嗜热侧孢霉(Sporotrichum thermophile Apinis)产植酸酶的情况。对发酵后的芝麻油饼进行扫描电子显微镜观察,发现霉菌生长密集,分生孢子丰富。通过Plackett-Burman设计确定葡萄糖、硫酸铵和培养时间是最显著的因素。采用响应面法的中心复合设计确定的最大植酸酶产量的关键成分最佳值为葡萄糖3%、硫酸铵0.5%和培养时间120小时。通过优化,植酸酶产量总体提高了2.6倍。在搪瓷涂层金属托盘中底物层深度为1.5厘米时,酶产量最高(348.76 U/g干物质残留)。该酶从面粉和豆浆中释放出无机磷酸盐,同时实现了脱植酸并释放出可溶性无机磷酸盐。