Chu Yu-Hao, Yu Xin-Xin, Jin Xing, Wang Yu-Tang, Zhao Duo-Jia, Zhang Po, Sun Guang-Mei, Zhang Ying-Hua
Key Laboratory of Dairy Science, Ministry of Education, Northeast Agricultural University China
Department of Food Science, Northeast Agricultural University Harbin 150030 P. R. China.
RSC Adv. 2019 Jan 2;9(1):354-360. doi: 10.1039/c8ra08921c. eCollection 2018 Dec 19.
Alkaline phosphatase (ALP) excreted from lactic acid bacteria (LAB) showed the ability to degrade organophosphorus pesticides. This study reported the first purification and characterization of ALP from LAB. The molecular weight of ALP was estimated to be 43 kDa measured by SDS-PAGE. The activity of purified enzyme was determined with the binding of -nitrophenyl phosphate as the substrate. The results showed that the optimal temperature for ALP activity was 37 °C, and the optimal pH was 8.5. But ALP was stable at temperatures below 32 °C. The ALP activity remained at 80% when the pH was 8-9.5. The enzyme activity could be activated by Mg, Ca, and inhibited by Cu, Zn, and EDTA. The Michaelis-Menten constant was 6.05 mg kg with dimethoate as the substrate according to the Lineweaver-Burk plots. These results highlight an important potential use of ALP from LAB for the cleanup of pesticide pollution in raw materials for the food industry.
乳酸菌分泌的碱性磷酸酶（ALP）具有降解有机磷农药的能力。本研究首次报道了从乳酸菌中纯化和鉴定ALP。通过SDS-PAGE测定，ALP的分子量估计为43 kDa。以对硝基苯磷酸酯为底物结合来测定纯化酶的活性。结果表明，ALP活性的最适温度为37℃，最适pH为8.5。但ALP在32℃以下温度时稳定。当pH为8-9.5时，ALP活性保持在80%。该酶活性可被Mg、Ca激活，被Cu、Zn和EDTA抑制。根据Lineweaver-Burk图，以乐果为底物时，米氏常数为6.05 mg/kg。这些结果突出了乳酸菌来源的ALP在食品工业原料农药污染清理方面的重要潜在用途。
