[New method for the observation of gas-production using fiber-stuffed tube for coliform detection and EC-test]

Gas production in lactose-containing medium (e.g., BGLB, LB, or EC medium) is the most important characteristic in the E. coli/Coliform group (C.F.G.) test on food and water. Generally a Durham tube is used as the fermentation tube, and the collected gas is analyzed. However, difficulties can arise, such as insufficient gas volume or muddy precipitates. Since air clings well to fibers in water, the Tsunoda tube (T-tube), a stalk-like tube stuffed with synthetic fibers which can capture the gas more precisely and easily, was designed. With this T-tube, air elimination during the preparation of the medium and detection of gas, even in small quantities, are both simplified. Our results show that the T-tube can replace the Durham tube as a device for detecting gas-production by the E. coli/Coliform group, with improved accuracy and sensitivity.