Inhibitory activity against the growth of Escherichia Coli 0157
The Sanyo Shimbun newspaper, Sept:29,1996 issue

"One species of lactic acid bacteria inhibits the growth of O-157" — confirmed by a laboratory in the Faculty of Agriculture, Okayama University.

Professor Hidehiko Tanaka in the Laboratory of Applied Biochemical and Biotechnology in the Faculty of Agriculture, Okayama University discovered that the ingredients in a certain species of lactic acid bacteria used in Malaysian foods Tempeh has antibacterial effects against O-157 by 28th. It is quite rare to show the results in experiments. Although we have heard of some opinion saying for antibacterial effects against O-157, it is ideal to have catechin, ingredients in astringency of Japanese green tea, or citric acid in pickled ume or Japanese plum.

Tempeh is a food with soybean as its ingredients, resembling to Japanese natto or fermented soybean. This species of lactic acid bacteria is what Prof. Dr. Iichiro Ohhira brought back to Japan and is under the research of the laboratory. Dr.Ohhira is an alumnus of Okayama University, now advising agriculture in Malaysia. Two years ago, the laboratory found out the antibacterial effects against MRSA, methicillin resistant Staphylococcus aureus, and started their experiments from this summer investigating their question whether the above bacteria has a simmilar effects against O-157.

In previous experiments, they extracted the ingredients of the above bacteria with acetic acid ethyl, controlled pH, exponent of hydrogen ion concentration, and made it neutral Then they applied the extract of the lactic acid bacteria on a laboratory dish where O-157 is cultivated in 6 stages from 0.75mg to 24mg. Being observed for 48 hours at 37°C, which is closed to human temperature. As a result, the extract of more than 3.0mg level inhibited the growth of O-157. It is also found that the more the volume of the extract, the stronger the inhibitory effect. Experiments were repeated several times with similar results.

Prof. Tanaka says "we still do not know which substance effects on O-157, but we are sure it is a substance with low volume of molecules." They keep on investigation to specify the substance and reveal of activity mechanism.

To apply for medicine
Talk by Prof. Toshio Miwatani of Bacteriology at Okayama Prefectural University: Since researches on O-157 have just started, it is such an interesting research. If we can specify the substance, we might be able to apply it to foods or medicine.