| 摘要: |
| 利用扫描电镜技术、X-射线粉末衍射技术和弱酸去钙法, 对菲律宾蛤仔、文蛤、厚壳贻贝、泥蚶、缢蛏5种习见海洋经济贝类贝壳的断面微观结构、物相组成、有机基质和蛋白质含量等进行了观察和分析。电镜观察结果显示, 5种贝壳的微观结构主要包含棱柱层和珍珠层; 棱柱层晶体结构有斜棱柱层、球棱柱层、棱柱层、均质层和交错板状层5种类型, 其中缢蛏只有斜棱柱层, 而泥蚶除球棱柱层外, 其他4种晶体类型均存在, 此复杂结构可能与其贝壳强度大有关; 珍珠层晶体结构有珍珠层和肌棱柱层2种类型, 其中厚壳贻贝的珍珠层呈典型的“砖-泥”结构, 具有明显的层状结构, 其余4种贝壳珍珠层均由不规则块状结构组成。X-射线衍射结果显示, 菲律宾蛤仔、文蛤、缢蛏和泥蚶4种贝壳都属于文石质壳体, 无机相几乎由文石组成, 而厚壳贻贝属于混合质壳体, 无机相由文石和方解石组成; 贝壳化学成分分析显示, 5种贝壳有机质含量均为3%左右, 而总蛋白含量占有机质的2.98%~7.21%, 其中可溶性蛋白是不可溶蛋白含量的5.55~20.31倍。上述结果为贝壳形成机理的研究积累了基础资料。 |
| 关键词: 贝壳 微观结构 有机质 扫描电镜 X-射线衍射 |
| DOI：10.11759/hykx20201217003 |
| 分类号:S91 |
| 基金项目:国家重点研发计划“蓝色粮仓科技创新”专项课题(2018YFD0901405); 浙江省农业新品种选育重大科技专项课题(2021C02069-7); 宁波市重大科技攻关暨“揭榜挂帅”项目(2021Z114); 国家海洋水产种质资源库项目 |
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| Microstructure and composition analysis of five species of economic bivalves |
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MO Tian-bao1,2,3, XU Hong-qiang4, HE Jing4, DONG Ying-hui2,3, LIN Zhi-hua2,3,4
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1.National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China;2.Zhejiang Key Laboratory of Aquatic Germplasm Resources, College of Biological &3.Environmental Sciences, Zhejiang Wanli University, Ningbo 315100, China;4.Ninghai Marine Biological Seed Industry Research Institute, Zhejiang Wanli University, Ninghai 315604, China
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| Abstract: |
| Five popular species of marine bivalves, Ruditapes philippinarum, Meretrix meretrix, Sinonovacula constricta, Tegillarca granosa, and Mytilus coruscus, living off the east coast of China, were selected for shell structure characterization and chemical composition analyses using scanning electron microscopy, X-ray diffraction, and decalcifying in a weak acid. Scanning electron microscopy results showed that the shells comprised a prismatic layer and nacre layers. Additionally, the prismatic crystal structure included five types: fibrous prismatic, spherical prismatic, prismatic, homogeneous, and crossed lamellar layers. S. constricta had only a fibrous prismatic layer, while T. granosa had all types of layers except a spherical prismatic layer. These differences might be related to shell-crushing resistance. The nacre crystal structure contains nacreous and myostracum layers. The nacreous layer of M. coruscus showed an obvious layered structure that was a typical brick-mud structure, while the other four shells presented an irregular blocky structure. The X-ray powder diffractometry results showed two types of shells in the five mollusks, namely aragonite shells and calcite shells. In four species, R. philippinarum, M. meretrix, S. constricta, and T. granosa, the inorganic phases were almost entirely composed of aragonite, while the M. coruscus inorganic phase was composed of aragonite and calcite. The organic matrix content in the five bivalves was approximately 3%, and the total protein content accounted for 2.98%–7.21% of the organic matrix, among which the content of soluble protein was 5.55–20.31 times that of insoluble protein. The information obtained from this study will provide a reliable scientific basis for biomineralization. |
| Key words: bivalves shell organic matter SEM XRD |
