Department of Soil Science, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.
Department of Food Technology and Bioprocess Engineering, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Karlsruhe, Germany.
J Sci Food Agric. 2018 Aug;98(10):3667-3674. doi: 10.1002/jsfa.8845. Epub 2018 Feb 19.
Phytases are a diverse group of enzymes initiating the dephosphorylation of phytate. Phytate is considered as an anti-nutritional compound because of its capability to chelate nutrients such as Fe , Zn , Mg , and Ca . In this study, several bacterial isolates obtained from earthworm casts were evaluated for their phytate degrading capability. Enzymatic properties and the sequence of the corresponding phytase-encoding gene of the selected isolate were determined.
The phytase exhibited its highest activity at pH 4.0 and was stable from pH 3 up to pH 9. The temperature optimum was determined to be 65 °C. The strongest inhibitors of enzymatic activity were identified as vanadate, Cu , and Zn . High-performance ion chromatography analysis of enzymatic phytate dephosphorylation revealed that the first dephosphorylation product was d/l-myo-inositol(1,2,3,4,5)pentakisphosphate.
Owing to its enzymatic properties, such as tolerance to tartrate and the presence of the consensus motifs PDTVY, GNHE, DLG, VLFH, and GHDH, this phytase could be classified as a purple acid phytase. To the best of our knowledge, this is the first report describing a bacterial purple acid phytase. © 2017 Society of Chemical Industry.
植酸酶是一类能够启动植酸去磷酸化的酶，具有多样性。由于植酸能够螯合 Fe、Zn、Mg 和 Ca 等营养物质，因此被认为是一种抗营养物质。在本研究中，我们评估了从蚯蚓粪便中分离得到的几种细菌菌株的植酸降解能力。我们还测定了所选菌株的植酸酶编码基因的酶学特性和序列。
该植酸酶在 pH4.0 时表现出最高的活性，在 pH3 到 pH9 之间稳定。最适温度为 65°C。酶活性的最强抑制剂鉴定为钒酸盐、Cu 和 Zn。对酶解植酸脱磷酸化的高效离子色谱分析表明，第一个去磷酸化产物是 d/l-肌醇(1,2,3,4,5)五磷酸。
由于该植酸酶具有耐酒石酸盐和存在 PDTVY、GNHE、DLG、VLFH 和 GHDH 等保守基序等酶学特性，可将其归类为紫色酸性植酸酶。据我们所知，这是首次报道细菌紫色酸性植酸酶。 © 2017 英国化学学会。
