BCOJ Analysis Committee (1), YASUO MOTOYAMA (2), Nao Kaneko (2),
Satoshi Shimotsu (2), Satomi Naito (2), Takaaki Fujiwara (2), Tomoko
Uehara (3), Toshinao Shimabukuro (3), Hiroko Kosugiyama (4), Mitsutaka
Sometaya (4), Toshio Fujii (4), Takako Yanagisawa (4), Takeo Ishihara
(5), Hajime Kanda (5), Naoto Harakawa (6), Kumiko Matsubara (7), Keiko
Togami (8), Chikage Yamamoto (9)
(1) Brewery Convention of Japan, Moriya-shi, Ibaraki, Japan; (2) Asahi
Breweries, Ltd., Moriya-shi, Ibaraki, Japan; (3) Orion Breweries, Ltd.,
Nago, Okinawa, Japan; (4) Kirin Group Office Co. Ltd., Tsurumi-ku,
Yokohama-shi, Kanagawa, Japan; (5) Sapporo Breweries, Ltd., Yaizu-shi,
Shizuoka, Japan; (6) Sapporo Breweries, Ltd., Hita-shi, Oita, Japan; (7)
Suntory Liquors, Ltd., Shimamoto-cho, Mishima-gun, Osaka, Japan; (8)
Suntory Business Expert, Ltd., Shimamoto-cho, Mishima-gun, Osaka, Japan;
(9) Sysmex Corporation, Nishi-ku, Kobe-shi, Hyogo, Japan
BioBall® is a freeze-dried reference material for quality
control of media which contains constant numbers of viable cells. As
commercially available products, BioBall® series contain 19 different organisms, such as Bacillus subtilis, Escherichia coli, Clostridium sporogenes, and so on. Recently, BioBall® of Lactobacillus brevis DSM6235 strain has been newly developed. In this trial, BioBalls®
with four powder media (MRS, Raka-Ray, BMB, and UBA) were sent to each
collaborator. Each medium was prepared as per the manufacturer’s
instructions. BioBall® was spread onto each medium, and CFUs
were counted after 7 days of anaerobic cultivation. The results were
evaluated according to “basic method for the determination of
repeatability and reproducibility of a standard measurement method” in
JIS Z 8402 and “design of experiments (ANOVA)” in JIS Z 8101 guidelines.
Mandel’s h and k, Cochran’s test, and Grubb’s test were
used in the statistical evaluation of the data to identify outliers. The
repeatability relative standard deviation (RSDr) for the detection of
CFU by each medium ranged from 6.4 to 8.4%, and the reproducibility
relative standard deviation (RSDR) ranged from 7.7 to 13.3%, respectively. The ratio of SR and Sr (1.2–1.7) is below the empirical threshold of 2.5. Therefore, the RSDr and the RSDR
were judged acceptable. The comparison of CFU averages among four media
using the one-way ANOVA showed no differences at the 5% significance
level. From these results, the BCOJ subcommittee recommends that this
BioBall® method be suitable for the quality control method of
beer-spoiler’s detection media and be adopted for inclusion in the BCOJ
Microbiology Methods.
Yasuo Motoyama received a B.S. degree in agricultural chemistry from
the Tokyo University of Agriculture and Technology, Japan. He joined
Asahi Breweries, Ltd. in 1990. He received a Ph.D. degree from Tokyo
University in 2003. Since 2008, he has been working on microbiological
quality assurance in breweries and developing detection technology for
beer-spoilage microorganisms.
VIEW PRESENTATION