碩士 / 國立海洋大學 / 水產養殖學系 / 89 / This study investigated the characteristics and pathogenicity of bacterial strains 890926 and SL5, isolated from moribund diseased small abalone, Haliotis diversicolor supertexta. Both of the two strains were characterized and identified as Vibrio alginolyticus on the basis of various biochemical, physiological, API 20E kids and Biolog GN kits tests. In addition, V.alginolyticus ATCC 17749 was used as a reference strains.
These two field strains were resistant to ampicillin, penicillin G, and vancomycin while susceptible to chloramphenicol, ciprofloxacin, doxycycline-HCl, erythromycin, nalidixic acid, nitrofurantoin, oxolinic acid and oxytetracycline. Furthermore, strain 890926 originally isolated in I-Lan, Taiwan, was resistant to novobiocin but susceptible to furazolidone. Strain SL5 originally isolated in Fu-Ken, China, was resistant to furazolidone but susceptible to novobiocin.
The 890926 strain and its extracellular products(ECP) were virulent to small abalone especially when the animals were kept in higher temperature(28℃). The majority of the tested animals were killed within 24h at higher dose. The protease activities of ECP from strains 890926 and SL5 grown on TSA(+3﹪NaCl), at 30℃ for 24h, were3629 and4869 hide powder azure digestibility unit/mg protein, respectively. The ECPs of both strains showed caseinase and gelatinase activity. The protease activities in the ECPs of 890926 strain and partially purified fractions were apparently inactivated at 50℃ indicating that the protease(s) produced by V. alginolyticus is heat labile. The optimal pH for the protease in both preparations was at pH6. The protease activity was inhibited by PMSF, TPCK(serine protease inhibitors) and EDTA while not inhibited by other inhibitors tested. This result revealed that the major protease activity present in the ECP is serine protease. As partially purified protease was lethal to the abalone, the serine protease may play an important role in the lethality of the bacterium.
| Identifer | oai:union.ndltd.org:TW/089NTOU0086026 |
| Date | January 2001 |
| Creators | ShaoYuan Wang, 王少元 |
| Contributors | PingChung Liu, 劉秉忠 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 70 |
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