Zimmermann B, Lantzsch H-J, Langbein U, Drochner W
Institute of Animal Nutrition, Hohenheim University, Stuttgart, Germany.
J Anim Physiol Anim Nutr (Berl). 2002 Oct;86(9-10):347-52. doi: 10.1046/j.1439-0396.2002.00393.x.
In contrast to supplemented microbial phytases, considerably lower cereal phytase activities were found after application of an enzyme solution extracted in citrate/NaOH buffer (pH 5.5) for 1 h as compared with the direct incubation of the plant material. Differences between both methods obtained were 70% for wheat and spelt and 50% for barley and rye. The determination of phytase activity of a wheat sample by direct incubation was affected by the sample size and amount of substrate (Na-phytate) added. Optimal conditions are a maximal level of phytase activity of < or = 0.05 U incubated for 60 min in a buffered solution (citrate/NaOH, pH 5.5) with 10 ml of 32.6 mmol/l Na-phytate at 37 composite function C. Possible reasons for the differences between both methods and for the factors affecting phytase activity by direct incubation are discussed.
与添加的微生物植酸酶相比，用柠檬酸盐/氢氧化钠缓冲液（pH 5.5）提取1小时后的酶溶液处理植物材料后，谷物植酸酶活性明显低于直接培养植物材料。两种方法的差异在小麦和斯佩尔特小麦中为70%，在大麦和黑麦中为50%。直接培养法测定小麦样品的植酸酶活性受样品大小和添加底物（肌醇六磷酸钠）量的影响。最佳条件是在37℃下，将10毫升32.6毫摩尔/升的肌醇六磷酸钠加入到缓冲溶液（柠檬酸盐/氢氧化钠，pH 5.5）中，在<或 = 0.05单位的最大植酸酶活性水平下孵育60分钟。文中讨论了两种方法之间存在差异以及直接培养法影响植酸酶活性的因素的可能原因。
