MONITORING OF FECAL POLLUTION IN COASTAL WATERS BY USE OF RAPID ENZYMATIC TECHNIQUES

Enzyme assays for 4-methylumbelliferyl-beta-D-galactopyranosidase and 4-methylumbelliferyl-beta-D-glucuronidase activities were used for rap id detection (25 min) of fecal water pollution and to determine the im pact of sewage discharge in coastal waters. Two coastal areas were inv estigated: (i) an estuary characterized by a high degree of contaminat ion downstream of a discharge from a sewage treatment plant and a low degree of water renewal and (ii) a fjord with a low degree of pollutio n and a high degree of water renewal. Statistical analysis showed that a global correlation curve could be used to estimate concentrations o f culturable fecal coliform bacteria in the two coastal areas, althoug h environmental factors important for cell physiology (e.g., salinity) varied at different sampling locations. The sensitivity limit for det ection of 4-methylumbelliferyl-beta-D-glucuronidase activity correspon ded to bacterial concentrations on the order of 10 to 100 CFU/100 ml. The 4-methylumbelliferyl-beta-D-galactopyranosidase assay was less sen sitive because of a higher rate of substrate autohydrolysis. The detec tion limit corresponded to bacterial concentrations on the order of 10 0 to 1,000 fetal coliforms per 100 mi.