碩士 / 國立高雄海洋科技大學 / 水產食品科學研究所 / 102 / Hydrolytic products of red algal polysaccharides, agar, are confirmed to have many biological activities. An agarase-producing bacterium FY is studied and characteristics of its agarases are investigated in this thesis. The enzyme activitystaining after electrophoresis showed that agarases with molecular weight about 43-52 kDa display higher enzyme activity. Therefore, agarases derived from FY fermrntatuon broth after desaiting are purified by gel filtration and anion exchange chromatography, purified molecule of agar about 50 kDa enzyme, and its characteristics were discussed. The results indicate that the optium cultivation temperature and pH of the purification agarase are 30 oC and 3, respectively. The metal ions Co+ 2 and Mn+ 2 increase FY agarase activity, but Hg+2 inhibit its activity. The activity of the purification agarases not reduced by addition of citric acid, EDTA, magnesium sulfste, and potassium dihydrogen phosphate. In addition, FY agarases display detergent-tolerant activity because many detergents have no significant effect on their agarase activity. Moreove, the FY agarases are salt-tolerant when the NaCl concentration increased to 6 M, the further 99% activity. In addition, that thermal stability and pH stability of the purified agarase are 50 oC and 9, respectively. In this study, the purified enzyme FY km and Vmax were 0.56 μg/ ml and 14.36 mg/ ml/ hr, and the purified enzyme was β-agarase, as it was able to hydrolyze agarose, releasing neoagarotetraose, neoagarohexaose and neoagarooctaose as the products. These oligosaccharides may be further utilized to add functional food.
| Identifer | oai:union.ndltd.org:TW/102NKIM0084015 |
| Date | January 2014 |
| Creators | Chih-Jung Chen, 陳芝蓉 |
| Contributors | Jing-Iong Yang, 楊景雍 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 106 |
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