Kinase experiment:

GLUase activity of E. coli cells is measured. Three millilitres of 4-Methylumbelliferyl-β-D-glucuronide hydrate (MUGlu) solution (55 mg of hydrated MUGlu and 20 mL of Triton X-100 in 50 mL of sterile water) is added to each flask (final concentration:165 mg/L). The incubation temperature is 44℃. One hundred microlitres of 2 M NaOH solution is added to each 2.9-mL aliquot to obtain a pH>10 before the fluorescence measurement[1].

4-Methylumbelliferyl-β-D-glucuronide hydrate is a fluorogenic substrat (λex=362 nm , λem=445 nm).

4-Methylumbelliferyl-β-D-glucuronide hydrate is a fluorogenic substrat with λex=362 nm and λem=445 nm. The half-saturation constants, Km, that are calculated for sewage samples are close to the Km values calculated based on experimental plots presented previously for freshwaters[1].

[1]. George I, et al. Use of beta-D-galactosidase and beta-D-glucuronidase activities for quantitative detection of totaland fecal coliforms in wastewater. Can J Microbiol. 2001 Jul;47(7):670-5.