並列タイトル等Functionality of lactic acid bacteria in traditional fermented food of Xinjiang, China
一般注記In this study, the author collected traditional fermented dairy products from several pastoral area of Xinjiang, China. Nineteen lactic acid bacteria (LAB) were isolated from kurt, cheeses, fermented camel’s milk, koumiss, and other dairy products and identified by 16S rDNA sequencing analysis. Antibacterial activity of cell free supernatants (CFS) of fermented LAB against bacterial pathogens was determined by agar well diffusion method, indicating that the supernatants were found to have potent antibacterial activity for health care.Eleven isolates of Lactobacillus and eight of Enterococcus were identified as belonging to 7 validated species, L. plantarum, E. hirae, E. faecium, E. lactis, L. casei, L. zeae, and E. lactis. Among them, L. plantarum, L. zeae, and E. hirae lactic acid bacteria (99% homology) were found to have high antibacterial activity (6-9 mm clean zone) against E. coli at neutral pH, suggesting that the antibacterial activity was originated by antibacterial peptides. These lactic acid bacteria were cultured in large scale, and then antibacterial peptides were isolated.In our laboratory, several lactic acid bacteria were isolated from a traditional Mongolian Airag and identified some lactic acid bacteria. Two lactic acid bacteria, L. hilgardii and L. diolivorans, were found to have high antibacterial and proteolytic activities. Therefore, in this thesis, in order to increase the nutritional value of potato pulp, which is discarded without being effectively utilized in starch production, as a livestock feed, a fermentation study using L. diolivorans lactic acid bacteria was conducted.The moisture content of the potato pulp silage was remained 822 g/kg before and after ensiling. After drying for 48 h at 60°C and subsequently for an additional 4 h at 105°C, the moisture content was reduced to 82–84 g/kg. The protein content in the silage increased from an initial concentration of 39 to 57 g/kg and 58 g/kg for L. lactis and L. diolivorans inoculations, respectively. The NDF content decreased slightly from 363 to 360 g/kg (L. lactis) and 354 g/kg (L. diolivorans) after inoculations. Similarly, ADF content showed a small decrease from 348 to 345 g/kg and 325 g/kg for L. lactis and L. diolivorans inoculations, respectively. The soluble sugar content increased roughly by 2 folds in both treatments. The lactic acid content significantly increased from 2 to 52 g/kg (L. lactis) and 50 g/kg (L. diolivorans) after ensiling, whereas, toxic butyric acid was not detected with either treatment. These results suggest that the inoculation of potato pulp with L. lactis or L. diolivorans increases the quality and nutrition of potato pulp as silage. In particular, L. diolivorans is an efficient inoculant because it produces antibacterial peptides that prevent the increase of saprophyte in silage.
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受理日（W3CDTF）2020-10-06T21:18:06+09:00
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