Determination the changes of E. coli depuration times in Ruditapes decussatus and Venus verrucosa by production area and species differences

In this study, two important economic bivalve mollusc species, grooved carpet shell (Ruditapes decussatus) and warty venus (Venus verrucosa) were contaminated with Esherichia coli (E. coli) and the time-dependent changes in their ability to depuration process. At the same time, after the natural E. coli loads of these two species were determined, the natural depuration times were also determined by subjecting them to depuration process separately. In addition to this, it was also tried to determine whether the differences in both bacterial load and production area influence the depuration time by comparing the species grown in production areas with different commercial fishing permits for the carpet shell.The natural E. coli loads of the carpet shell and warty venus samples used in the research were determined as ۱۵۰۰ MPN/۱۰۰ g in batch-A samples, ۴۳۰ MPN/۱۰۰ g in batch-B samples while the level was determined as ۷۴ MPN/۱۰۰ g warty venus samples. The naturally loaded sample decontamination process was completed ۱۸ hours after the start of the process for batch-A samples and ۶ hours after the start of the process for batch-B and warty venus samples, and it was determined that the products reached Class A production area standards.In the contamination application and E. coli level ۲۹۰۰ MPN loaded batch A-B and warty venus samples; warty venus samples were decontaminated at the ۱۲th hour, batch A-B samples were decontaminated at the ۱۸th hour, and they reached class A production area standard (<۲۳۰ MPN). As for the samples loaded with ۴۶۰۰ MPN, batch-A and warty venus samples reached the Class A production area standard after ۲۴ hours and batch B samples reached the Class A production area standard after ۴۸ hours. As a conclusion, species, andsample collection sites may have effect on depuration characteristics of E. coli and this may be related to physiological conditions of the specimens during the collection sites.

Keywords:

Ruditapes decussatus , Venus verrucosa , E. coli , depuration , bivalve