**9. MUG (beta-glucuronidase) of** *E. coli*

MUG is an acronym for 4-methylumbelliferyl-β-d-glucuronide, most strains of *E. coli* (97%) produce the enzyme β-d-glucuronidase hence, the detection of this enzyme is commonly employed in laboratories to identify and differentiate such organisms [44]. β-d-glucuronidase is an enzyme that hydrolyzes the beta-d-glucopyranoside-uronic derivatives to aglycons and d-glucuronic acid. In about 97% of *E. coli* strains, the enzyme-glucuronidase is present [45].
