著者

Aya Iwamoto Tomoyo Nakamura Naoki Narisawa Yukimasa Kawasaki Shin Abe Yasuyoshi Torii Hidenobu Senpuku Fumio Takenaga

出版者

Japanese Society for Food Science and Technology

雑誌

Food Science and Technology Research (ISSN:13446606)

巻号頁・発行日

vol.24, no.1, pp.129-137, 2018 (Released:2018-03-24)

参考文献数

33

被引用文献数

3 5

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Our previous study indicated that certain commercially available proteases inhibit biofilm formation by cariogenic streptococci. Natto made from soybeans cultured with Bacillus subtilis natto contains an abundance of proteolytic enzymes. In this study, we investigated the correlation between the protease activity of extracts from 36 commercially available natto products and the inhibition of biofilm formation. The biofilm inhibitory effect was found to correlate with the level of protease activity in the natto extracts, without reducing the viable cell numbers. The natto extract markedly inhibited the production of a water-insoluble glucan by Streptococcus mutans, which is the main agent involved in the formation of biofilm by cariogenic streptococci. The characteristics of the protease present in the extract were similar to those of nattokinase. Our results indicate that the protease activity exhibited by extracts of the Japanese fermented food natto reduces the risk of caries by inhibiting biofilm formation.

著者

Yusuke Kamiyoshihara Shinji Mizuno Mirai Azuma Fumika Miyohashi Makoto Yoshida Junko Matsuno Sho Takahashi Shin Abe Hajime Shiba Keiichi Watanabe Hiroaki Inoue Akira Tateishi

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-142, (Released:2018-01-26)

被引用文献数

1

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Avocado fruit ripen with ethylene production after harvest and the flesh becomes soft and edible due to degradation of cell wall polysaccharides during ripening. α-l-Arabinofuranosidase is a hydrolytic enzyme known to digest arabinose-containing cell wall polysaccharides. It has been shown that its activity increased with fruit ripening. However, our previous study showed that an α-l-arabinofuranosidase gene (PaArf/Xyl3A) is expressed in the avocado fruit before ethylene production. In addition, the transcripts were detected in some organs in which the level of ethylene was extremely low. These results indicate that the gene expression is independent of ethylene. In the present study, we carried out immunoblot analyses of α-l-arabinofuranosidase at the protein level. Using a polyclonal antibody raised against Japanese pear α-l-arabinofuranosidase, two α-l-arabinofuranosidase proteins with molecular masses of 72 kDa and 68 kDa, presumably belonging to glycoside hydrolase family 3, were detected in ripening avocado fruit. The protein levels in ethylene or 1-methylcyclopropene (1-MCP)-treated fruits were examined and the results indicated that the two proteins responded to ethylene in opposite ways; the 68 kDa protein showed a temporary accumulation, whereas the 72 kDa protein exhibited dissipation possibly caused by a loss of stability. The total enzyme activity of α-l-arabinofuranosidase was elevated faster in the ethylene-treated fruit throughout ripening and was slower in the 1-MCP-treated fruit, suggesting the existence of another α-l-arabinofuranosidase, which did not cross-react with the antibody and was positively regulated by ethylene, in ripening avocado fruit.