碩士 / 臺灣大學 / 動物學研究研究所 / 95 / Nervous necrosis virus (VNN) has caused mass mortality of many cultured fish species at larval stage. Probiotics become more important in the control of virus infection other than physical or chemical methods and immunization by vaccine. A few strains of bacteria were isolated from grouper intestine, including strain 0409, and were found to exhibit anti-NNV activity in vitro and in vivo (Chang, 2004). The aim of the present study is to analyze the biological and physiochemical properties of antimicrobial metabolites derived from strain 0409, use HPLC and FPLC to pure antiviral substrate, and to characterize its anti-NNV mechanism in GF-1 cell line. The anti-NNV components in the metabolites of strain 0409 were found to be heat-stable, wide-pH tolerant, proteinase K-resistant, high polar and smaller than 5 kD. The anti-NNV components were separated by Gel filtration, and the collected fractions were analyzed by absorbance of protein, total glycan staining and antiviral activity. It is suggested that the anti-NNV substance secreted by strain 0409 is highly to be a small peptide with aromatic group. During in vitro experiment, the culture supernatent of strain 0409 did not neutralize virions directly or block the viral receptor on cell membrane. According to the results of real-time PCR and Western blot, it was found that the amplification of NNV nucleic acids and capsid protein were inhibited only in NNV-infected cells co-cultured with the supernatants of strain 0409, therefore, it is suggested the mechanism of anti-NNV substances is through the depression of viral nucleic acids.
| Identifer | oai:union.ndltd.org:TW/095NTU05312028 |
| Date | January 2007 |
| Creators | Li-Shiuan Chu, 邱莉璇 |
| Contributors | 齊肖琪 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 50 |
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