Koichi Iwasaki

In vitro inactivation of Escherichia coli, Staphylococcus aureus and Salmonella spp. using slightly acidic electrolyzed water

In the current study, the effectiveness of slightly acidic electrolyzed water (SAEW) on an in vitro inactivation of Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Salmonella spp. was evaluated and compared with other sanitizers. SAEW (pH 5.6, 23mg/l available chlorine concentration; ACC; and 940mV oxidation reduction potential; ORP) was generated by electrolysis of dilute solution of HCl (2%) in a chamber of a non-membrane electrolytic cell. One milliliter of bacteria suspension (ca. 10-11 log(10)CFU/ml) was mixed with 9ml of SAEW, strong acidic electrolyzed water (StAEW; ca. 50mg/l ACC), sodium hypochlorite solution (NaOCl; ca.120mg/l ACC) and distilled water (DW) as control and treated for 60s. SAEW effectively reduced the population of E. coli, S. aureus and Salmonella spp. by 5.1, 4.8, and 5.2 log(10)CFU/ml. Although, ACC of SAEW was more than 5 times lower than that of NaOCl solution, they showed no significant bactericidal difference (p>0.05). However, the bactericidal effect of StAEW was significantly higher (p<0.05) than SAEW and NaOCl solution in all cases. When tested with each individual test solution, E. coli, S. aureus and Salmonella spp. reductions were not significantly different (p>0.05). These findings indicate that SAEW with low available chlorine concentration can equally inactivate E. coli, S. aureus and Salmonella spp. as NaOCl solution and therefore SAEW shows a high potential of application in agriculture and food industry as an environmentally friendly disinfection agent.

Instructional Technology and Design for a Distance Education Project Between UGA and Kagoshima University

An IT architecture was proposed herein to deliver synchronous distance education materials for an Applied Machine Vision course from UGA to Kagoshima University. This architecture was designed for extensive computer and Internet resources such as gigabits network, video conferencing and remote control software, but we had found that it could be adapted to minimal IT resources such as cable modem at 1 Mbps and audio-only feedback between teacher and students. Herein, system performance and student feedback for the first 7-weeks of class are reported and a prototype asynchronous WebCT version of this course is also described.