| 摘要: |
| 采用壳聚糖为载体，优化了海洋微生物YS2071脂肪酶的壳聚糖固定化条件。结果显示，在壳聚糖浓度为2% (m/v)、氢氧化钠浓度为12% (m/v)、乙酸浓度为1% (v/v)、戊二醛浓度为0.25% (v/v)、与戊二醛交联的时间为12 h及添加2 ml (1120 U)的游离脂肪酶时，固定化脂肪酶的活力最高，其活力回收率达到69.4%。对游离脂肪酶与固定化脂肪酶的酶学性质进行比较，结果显示，游离脂肪酶的最适反应温度为40℃，而固定化脂肪酶的最适反应温度为45℃，固定化脂肪酶的温度稳定性明显优于游离脂肪酶。最适反应pH均为8.0，脂肪酶经过固定化之后，酸碱耐受性增大。重复利用10次的固定化脂肪酶的酶活力保留率仍高于65%。固定化脂肪酶贮藏半衰期为96 d，而游离脂肪酶的贮藏半衰期是33 d。固定化脂肪酶与游离脂肪酶的酶活力保留率在不同有机试剂中表现出不同的稳定性。 |
| 关键词: 壳聚糖 海洋微生物脂肪酶 固定化 酶学性质 |
| DOI：10.11758/yykxjz.20150615 |
| 分类号: |
| 基金项目:国际科技合作与交流专项(2014DFG30890)、国家自然科学基金-联合基金(U1406402-5)和青岛市科技计划(13-4-1-57-nsh)共同资助。 |
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| Chitosan Immobilization of Lipase from Marine Microorganism YS2071 and Its Enzyme Characteristics |
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ZHANG Quan1,2, SHENG Jun1, LIU Junzhong1, ZHENG Hongfei1, SUN Mi1
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1.Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071;2.College of Food Science & Technology, Shanghai Ocean University, Shanghai 201306
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| Abstract: |
| Lipase (EC 3.1.1.3) is one of hydrolases that specifically catalyzes the hydrolysis of triglyceride. It plays an important role in the food improvement, the health care, and the environment protection. The lipase of our interest here is produced by a marine microorganism YS2071 and has high enzymetic capability. Chitosan is a type of biological sources which possesses good biocompatibility and biodegradation. It is a natural, biological, and macromolecular polysaccharide, the solution of which is a non-toxic and functional gel. Therefore, chitosan is an excellent immobilization carrier. The separation and recycling of materials have been a challenge in the industrial production process. In this study we aimed to solve this problem by immoblizing YS2071 lipase on a chitosan microsphere. The properties of the immoblized lipase was compared to the free lipase to verify the immobilization method. The activity of the immobilized enzyme reached the maximum when the conditions were as below: 2% chitosan (m/v), 1% acetic acid concentration (v/v), 0.25% glutaraldehyde concentration (v/v), 12% sodium hydroxide concentration (m/v), crosslinking time 12 h, and 2 ml (1120 U) enzyme. The recovered activity of the immobilized lipase was 69.4%. The optimal temperature for the functions of the free lipase and the immobilized lipase was 40℃ and 45℃ respectively. The optimal pH for both the free lipase and the immobilized lipase was 8.0. It was also showed that immobilization obviously increased the stability of the temperature and pH. After 10-time reuse the recovered enzyme activity was still higher than 65%. The storage half-life of the immobilized lipase was 96 days while it was only 33 days for the free lipase. The free lipase and the immobilized lipase exhibited distinct stabilities in different organic reagents. These results suggested that the immobilized lipase might have great values in the industrial process. |
| Key words: Chitosan Marine microorganism lipase Immobilization Enzyme characters |
