In recent years, the skin and muscle hemorrhagic ulcer occurred in grouper hatchery, suggesting that the bacteria extracellular protease was involved. In this study I surveyed the extracellular protease activity of marine bacteria and investigated the characteristics of the pathogen isolated from diseased grouper. The sampling sites of background survey were located along the coast of Taitung. The cultured media were MB2216 and PPESII. The extracellular protease activity was measured using milk seawater medium (MS) and dye-modified proteins of azocasein and azoalbumin. The extracellular protease activities of the marine bacteria were 1~5 U/mg. The average protease activities of the bacteria from MB2216 media were higher than those from PPESII media. The extracellular protease activity assay using azocasein and azoalbumin had similar tendency but the result by the clear zone measurement on the MS medium was of high variations. The FI-02 isolated from the diseased grouper skin was identified as Aeromonas hydrophila by the biochemicial characteristics and 16S rDNA sequence analysis. FI-02 was able to grow on the LB broth with 0~4% NaCl. The FI-02 was resistant to ampillicin, cefazolin, erythomycin, sulfisoxazole, whereas it was sensitive to streptomycin, doxycline, norfloxacin, cefotazime, oxolinic acid, and tetracycline. When FI-02 growing in the four media, the extracellular protease activities were higher than 4 U/mg. The highest protease activity was 6.08 U/mg when the bacteria grew on the LB medium. After heating on 27, 37, 42 and 56¢J for 20 mins, the protease activities remained the same. In the investigation of the fish immunity, owing to the complex compositions of the fish serum, no conclusion can be drawn on the specificity of the antibody against the bacterium.

In this study the gene expression pattern of a novel proteinase inhibitor II (PI-II) gene, PiA, in potato (Solanum tuberosum ), was analyzed using RT-PCR. The PiA gene was found to have enhanced expression in expanding tubers of a greenhouse-grown diploid clone (DC), different stages of 'Russet Burbank' tubers and expanding microtubers of in vitro-grown 'Russet Burbank' and 'Bintje'. PiA mRNA was more abundant in the tuber vascular ring and perimedullary zone areas than in other tuber tissues of DC. The PiA gene was also expressed in flower buds/flowers, shoot apices, leaf blades, stems and roots of 'Russet Burbank'. The PiA mRNA levels did not show significant change after IAA treatment in detached leaf blades and tubers of 'Russet Burbank'. Results suggest that the PiA gene is constitutively expressed and could be involved in tuber developmental processes. To the best of our knowledge, PiA is the first reported PI-II gene expressed in most tissues/organs of potato plants.

No description available.

No description available.

No description available.

No description available.

No description available.

Typescript (photocopy) / vi, 106 leaves, [11] leaves of plates : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Biochemistry, 1982

Thesis (Ph.D.) -- University of Adelaide, Dept. of Biochemistry, 1982. / Typescript (photocopy).

Licentiatavhandling (sammanfattning) Linköping : Linköpings universitet, 2006. / Härtill 2 uppsatser.