English
Top

Studies on Probiotics and Microbial Diversity in the Institute of Rainbow Trout

学友会セミナー

学友会セミナー

2006年開催 学友会セミナー

開催日時: 平成18年5月23日(火) 17:00~18:30
開催場所: 新総合研究棟4F会議室
講  師: Dr. Do-Hyung Kim
所  属: School of Life Science, Heriot-Watt University
演  題: Studies on Probiotics and Microbial Diversity in the Institute of Rainbow Trout
概  要:

Alternative strategies to chemotherapy are needed to control diseases in aquaculture. In this study, the microbial diversity of rainbow trout (Oncorhynchus mykiss) intestine revealed that most DNA sequences of uncultured and cultured members of the microflora were affiliated with a major phylum, Proteobacteria. However, the microbial diversity of the mucosal layer was different from that of intestinal contents. This suggests that the fish intestine harbours a larger diversity than was previously recognised. Carnobacterium maltaromaticum B26 and C. divergens B33, which were isolated from healthy rainbow trout intestine, were selected as probiotics. Thus, fish administered with B26 and B33 for 14 days when dosed at 107 bacterial cells g-1 of feed were protected against challenge with virulent strains of Aeromonas salmonicida and Yersinia uckeri.

The cultures, which persisted in the gut for up to 3 weeks after administration, enhanced the innate immune responses. Specifically, the use of B26 led to significantly enhanced phagocytic activity of the head kidney (HK) leucocytes, whereas B33 significantly increased the espiratory burst and serum lysozyme activity. Also, both cultures significantly stimulated the gut mucosal lysozyme activity. Furthermore, HK leucocytes co-cultured with B26 or B33 significantly raised the expression of IL-1β and TNF-α mRNA.

世 話 人: ○清野 宏
河岡 義裕