Mariscal A, Gómez-Aracena J, Varo M C, Fernández-Crehuet J
Departament of Preventive Medicine and Public Health, School of Medecine, University of Malaga, Campus Teatinos, 29071 Malaga, Spain.
Arch Environ Contam Toxicol. 1998 Nov;35(4):588-93. doi: 10.1007/s002449900420.
Most commercially available test kits for water and foodstuffs use beta-galactosidase activity for coliforms and beta-glucuronidase activity for Escherichia coli. We tested the effects on the beta-glucuronidase activity of E. coli W3110 of substances usually present in foods and several synthetic pharmaceutical compounds. Thirteen substances were tested: three carbohydrates, four flavonoids, five monosaccharide derivatives, and dimethyl sulphoxide. In a minimum medium without any other carbon source, glucose (0.1 mM), quercetin (0.1 mM), silymarin (10 mg/L), D-gluconic acid (0.01 mM), D-gluconic acid lactone (0.01 mM), isopropyl-beta-D-thiogalacto pyranoside (1 mM), p-nitrophenyl beta-D-glucuronide (1 mM), and DMSO (1 M) completely inhibited E. coli glucuronidase activity at the above concentrations. However, the following compounds stimulated E. coli glucuronidase activity within the ranges of concentrations shown: glucose (0.0001-0.01 mM), lactose and sucrose (>0.1 mM), D-saccharic acid 1,4 lactone (0.0001-0.1 mM), p-nitrophenyl beta-D-glucuronide (0.001-0.01 mM) and DMSO (2-500 mM). In a rich culture medium that contained other carbon sources (lauryl tryptose broth) E. coli glucuronidase activity in the presence of the extra nutrients was unaffected by the test substances and therefore, under normal conditions in water or foods, they should not interfere with E. coli assays based on measurements of beta-glucuronidase activity.
大多数市售的水和食品检测试剂盒利用β-半乳糖苷酶检测大肠菌群活性，利用β-葡萄糖醛酸酶检测大肠杆菌活性。我们测试了食品中常见物质以及几种合成药物化合物对大肠杆菌W3110的β-葡萄糖醛酸酶活性的影响。测试了13种物质：三种碳水化合物、四种黄酮类化合物、五种单糖衍生物和二甲基亚砜。在没有任何其他碳源的基本培养基中，葡萄糖（0.1 mM）、槲皮素（0.1 mM）、水飞蓟宾（10 mg/L）、D-葡萄糖酸（0.01 mM）、D-葡萄糖酸内酯（0.01 mM）、异丙基-β-D-硫代半乳糖苷（1 mM）、对硝基苯基-β-D-葡萄糖醛酸苷（1 mM）和二甲基亚砜（1 M）在上述浓度下完全抑制了大肠杆菌葡萄糖醛酸酶活性。然而，以下化合物在所示浓度范围内刺激了大肠杆菌葡萄糖醛酸酶活性：葡萄糖（0.0001 - 0.01 mM）、乳糖和蔗糖（>0.1 mM）、D-糖二酸1,4内酯（0.0001 - 0.1 mM）、对硝基苯基-β-D-葡萄糖醛酸苷（0.001 - 0.01 mM）和二甲基亚砜（2 - 500 mM）。在含有其他碳源的丰富培养基（月桂基胰蛋白胨肉汤）中，添加额外营养物质时大肠杆菌葡萄糖醛酸酶活性不受测试物质影响，因此，在水或食品的正常条件下，它们不应干扰基于β-葡萄糖醛酸酶活性测量的大肠杆菌检测。
