A fungus, strain No. 232 which produced arabinogalactan degrading enzymes in the culture filtrate, was isolated from coffee bean. Strain No. 232 was identified as Aspergillus fumigatus by morphological characteristics. When the fungus was cultured at 40°C for 7 days in a medium containing 5 garabinogalactan, 1g KH2PO4, 1g methionine or proline, 0.5g MgSO4·7H2O, 0.5g KCI and 1l distilled water, pH7.0, the maximal production of arabinogalactan degrading enzymes was obserbed. β- (1→3) and β- (1→4) arabinogalactan degrading enzymes were induced by addition of β- (1→3) arabinogalactan and gum arabic to the medium. But β- (1→3) arabinogalactan degrading enzymes were not induced by addition of β- (1→4) arabinogalactan, arabinogalactan constituent monosaccharides, mannan, xylan, and pectin to the medium.
The source of bacterial contamination on the shell surface of hen eggs on the farm was examined. No bacteria were detected on the shell surface of 55 (92%) out of 60 eggs obtained aseptically from the oviduct of old hens. On the shell surface of eggs taken just after being laid in disinfected cages an average of 104 CFU bacteria/egg were detected. On the shell surface of eggs, which were laid in commercial cages and carried to the front of the egg washer on transporting equipment an average of 105 CFU bacteria/egg were detected. As a supplementary experiment, shell eggs carefully washed, disinfected, and dried, were transported on three conveyers and a lifter. The surface of these eggs were contaminated with 103-104 CFU bacteria/egg on each equipment. Large numbers of bacteria were detected on egg conveyers and egg lifter on the farm by the swab test. Large numbers of bacteria were also detected in the air on the farm. Smaller numbers of bacteria were detected on the equipment and the air of the GP center (packing station) neighboring the farm. Bacteria isolated from the shell surface of eggs, egg transporting equipment, and the air were mainly gram positive bacteria such as Micrococcus and Staphylococcus. In conclusion, the degree of bacterial contamination on the shell surface of eggs when they were laid was small, but the contamination from equipment and the air during transport was very important.
In September 1995, three outbreaks of Salmonella Enteritidis infection occurred in Yamaguchi Prefecture. The isolates obtained from each outbreak were examined for drug susceptibility patterns, plasmid DNA profiles, and restriction fragment patterns of chromosomal DNA bypulsed-field gel electrophoresis (PFGE). The isolates from the three outbreaks could be differentiated by the PFGE analysis, but not the plasmid profile analysis. These findings suggest that the isolates obtained from each outbreak are genetically different clones, and that the combination of plasmid DNA analysis with the PFGE method is useful in more precise epidemiological analysis.
Antifungal activity of aqueous garlic extract against various yeasts isolated from seafoods was examined from the viewpoint of food sanitation. The aqueous garlic extract was prepared from homogenate of fresh garlic bulbs blended with an equal weight of water. This mixture was then sterilized by filtration. Eighteen different species of the five genera, Candida, Cryptococcus, Debaryomyces, Rhodotorula and Trichosporon, were used. The minimum inhibitory concentration (MIC) values of the extract against these yeasts were 0.31 to 1.25% by agar dilution method using YM agar, and the extract was effective in vitro against these yeasts. Survival curves in the presence of garlic extracts were made on the two strains, Cryptococcus laurentii M-3 and Trichosporon cutaneum E-5. The extract showed fungicidal activity against these yeasts. The combined effect of garlic extract and sodium chloride on several yeasts were also examined. The antifungal activity of the extract was increased by the addition of sodium chloride
Use of electrically acidified water (E. A. W.) has become popular for sanitation in the medical and food fields in Japan recently. Acidified sodium-hypochlorite solution (A. S. H. S.) is known to have strong germicidal action. Therefore we examined the differences between E. A. W. and A. S. H. S. in the germicidal action. We used solution of B. subtilis spores. Thegermicidal characteristics of E. A. W. and A. S. H. S. were similar. The relationship between the logarithmic number of survivors per milliliter and available chlorine concentrations was described a second-order function. The relationship between the logarithmic number of survivors per milliliter and treatment temperature was shown as a broken line: there seemed to be a turning point at around 20°C.The relationships between the logarithmic number of survivors per milliliter and treatment duration was similar to those of reported by MERCER'S.
Cryptosporidiosis is a disease caused by oocysts of Cryptosporidium parvum. In June 1996, about 1, 000 people in Saitama prefecture, Japan, became ill with a prolonged diarrhea after drinking water contaminated with oocysts of C. parvum. Therefore, waterborne cryptosporidiosis is gathering concern in Japan. The diagnostic methods are acid-fast stain and immunofluorescence of oocysts of C. parvum in feces. However, the methods for the concentration and detection of the oocysts in water from private supplies and river water involving many impurities have not been established in Japan. In this study, using the method for the concentration of viruses from water using cellulose, we examined whether the oocysts in river water can be concentrated with DEAEcellulose and eluting solution. The most efficient eluting solution was the solution consisting of 1ml Tween 80 and 10g NaCl in 1l pH 9 water.