摘要
植酸(Phytic acid)在谷物、豆类、油料等作物籽粒中的含量为1％～5％,籽粒中60％～90％的磷存在于植酸中。人和单胃动物消化道中无植酸酶,粮食中大量的植酸磷不能被利用而随粪便排入环境,既浪费磷资源,又对环境造成磷污染。同时,植酸还是一种广谱性抗营养因子。据报道,饲料中添加植酸酶可使植酸磷的利用率提高到70％,鸡猪粪磷含量分别降低50％和35％,并可提高对Ca、Zn、Fe和Cu等的吸收率,而饲养效果与添加无机磷相当甚至更好,故植酸酶在饲养业及环保业展示出广阔的应用前景。本文报道耐高温植酸酶菌株的筛选及其体外去玉米、豆粕和麸皮植酸磷的效果。
More than 50 cultures, all of which were Aspergillus sp., producing extracellular thermostable acid phytase have been selected from 569 soil samples. The phytase activities of the cultural filtrate produced by strains H46-1 and 59-2 in 3 days were, respectively, 5.5 and 4.8IU/ml; The optimum pH for enzymatic reaction were 1.5-2.5 for H46-1, 1.5-2.5 and 5.0 for 59-2. These phytases respectively retained 97% and 81% of their activities after was incubated at 70℃ for 90 min, and the residual activities after treatment with pepsin for 5 h at pH2.0 were 93.7% and 90.5%, respectively. About 88% of phosphorus of sodium phytate was released by the phytases. Both of the enzymes showed the ability to release phosphorus in corn, soybean and wheat bran at pH1.5-5.5, and the economical enzyme dosage in vitro was 0.11U per 100mg of cprn-soybean-wheat bran diet.
出处
《微生物学报》
CAS
CSCD
北大核心
1996年第6期476-478,共3页
Acta Microbiologica Sinica
基金
国家自然科学基金资助项目
关键词
曲霉
真菌
植酸酶
热稳定
Phytase, Phytic acid, Dephosphorylation, Feed additive
