Effects of Combined Ultrasound and Chlorine Treatment on the Reduction of Sanitary Indicative Microorganism in the Korean Freshwater Snail (Semisulcospira libertine)

The current study investigated the effects of ultrasound (US; 40 kHz, 320W, 5 or 10 min) and chlorine (CL; 100 ppm of Cl2, 5 or 10 min) combined treatment on the indigenous natural microorganism regarded as sanitary indicatives in Korean freshwater snail (Semisulcospira libertine). The numbers of total viable bacteria, coliforms, and yeast and mold in the fresh water nail were significantly reduced more (p0.05) by the UL and CL combined treatments than by US or CL single treatment. Single treatment with CL for 10 min showed a maximum 1.38 log reduction of total viable bacteria, while 5 min of US 5 min/CL 5 min, US 10 min/CL 10 min, US 10 min/CL 5 min, and US 10 min/CL10 min showed 2.1, 2.16, 2.21, and 2.43 log reduction, respectively. The number of coliforms were also revealed as 1.10 and 1.22 log reduction, respectively when combined treated with US 10 min/CL 5 min and US 10 min/CL 10 min. When combined treated with US 10 min/CL 10 min, there were a maximum 2.03 log reduction of yeast and mold.