瘤背石磺腹部皮肤的超微结构及其黏液抗菌特性分析  

Ultrastructure of abdominal skin of Onchidium reevesii and antimicrobial property of its skin mucus

作　　者：孙梦颖 沈和定[1,2,3] SUN Meng-ying;SHEN He-ding(National Demonstration Center for Experimental Fisheries Science Education(Shanghai Ocean University),Shanghai 201306,China;Key Laboratory of Marine Fauna Phylogeny and Evolution of Shanghai University(Shanghai Ocean University),Shanghai 201306,China;Shanghai Collaborative Innovation Center for Cultivating Elite Breeds and Green-culture of Aquaculture Animals(Shanghai Ocean University),Shanghai 201306,China)

机构地区：[1]水产科学国家级实验教学示范中心(上海海洋大学),上海201306 [2]海洋动物系统分类与进化上海高校重点实验室(上海海洋大学),上海201306 [3]上海市水产动物良种创制与绿色养殖协同创新中心(上海海洋大学),上海201306

出　　处：《南方农业学报》2024年第4期1225-1237,共13页Journal of Southern Agriculture

基　　金：国家重点研发计划“蓝色粮仓科技创新”重点专项(2020YFD0900802);上海市协同创新中心任务团队经费项目(A1-3605-21-000202)。

摘　　要：【目的】对瘤背石磺(Onchidium reevesii)腹部皮肤进行超微结构观察和皮肤黏液抗菌特性分析,为瘤背石磺皮肤免疫功能的研究和天然抗菌药物的开发提供参考依据。【方法】采集瘤背石磺腹部皮肤和皮肤黏液,采用光学显微镜和透射电镜观察瘤背石磺腹部(足部和足侧)皮肤结构、腺体和腺细胞特征,采用组织化学染色技术检测黏液细胞中的糖缀合物,用瘤背石磺皮肤黏液对7种致病菌进行处理,采用生长曲线法和抑菌圈法测定黏液的抑菌效果,并深入研究黏液对金黄色葡萄球菌(Staphylococcus aureus)和哈维氏弧菌(Vibrio harveyi)的抑菌机理。【结果】瘤背石磺腹部皮肤黏液细胞中含有较多酸性黏多糖;足部皮肤中的黏液腺呈圆形,含有混合型黏多糖的黏液储存在中央腺腔中,足侧皮肤中的颗粒腺也分泌酸性黏多糖。根据分泌囊泡形态和致密程度的不同,足部皮肤中的腺细胞可分为6种类型,足侧皮肤中的腺细胞可分为3种类型,分泌囊泡与细胞膜融合后以胞吐的方式向外分泌。瘤背石磺皮肤黏液对7种致病菌的生长曲线均表现出抑制作用,具有广谱抗菌活性,且抑菌圈直径测定结果显示,黏液对金黄色葡萄球菌和哈维氏弧菌的抑制效果最好。扫描电镜观察结果显示,经皮肤黏液处理后,金黄色葡萄球菌和哈维氏弧菌细胞表面出现畸形和裂纹,胞质内容物流出,同时OD260变化反映黏液可增加细菌细胞膜的通透性,表明黏液可有效破坏细菌细胞膜的完整性。此外,与不经皮肤黏液处理相比,经黏液处理后,金黄色葡萄球菌和哈维氏弧菌三羧酸循环关键酶活性和ATP含量均显著降低(P<0.05,下同),Na+/K+-ATPase活性显著升高,说明黏液能破坏细菌的能量代谢过程,导致细菌生长繁殖受阻。【结论】瘤背石磺腹部皮肤具有多种类型的腺体和腺细胞,其分泌的黏液可破坏细菌的细胞膜完整性及能量代谢【Objective】To provide a reference for exploring the immune function of Onchidium reevesii skin and deve-loping natural antimicrobial drugs,ultrastructural observation of O.reevesii abdominal skin and analysis of the antimicrobial properties of skin mucus were performed.【Method】Collected abdominal skin(foot and side of foot)and skin mucus from O.reevesii,observed skin structure,glandular and glandular cell characteristics by light microscopy and transmission electron microscopy,detection of glycoconjugates in mucous cells by histochemical staining technique was conducted and seven pathogenic bacteria were treated with skin mucus of O.reevesii,the growth curve method and zone of inhibition were used to determine the antimicrobial activity of the mucus,and the antimicrobial mechanism of the mucus was studied in depth with Staphylococcus aureus and Vibrio harveyi.【Result】The results showed that the mucous cells had a higher content of acidic mucopolysaccharides;the mucus glands in the foot were round,and mucus containing a mixture of mucopolysaccharides was stored in the central lumen of the glands;and the granular glands in the skin of side of foot secreted acidic mucopolysaccharides.According to the morphology and density of the secretory vesicles,there were six and three types of glandular cells in the skin of the foot and in the lateral skin of the foot respectively.And the secretory vesicles were attached to the cell membrane and secreted into the environment via exocytosis.O.reevesii skin mucus had an inhibitory effect on the growth curves of all seven pathogens,with broad-spectrum antibacterial activity,and the results of the zone of inhibition test showed the optimal inhibitory effect on S.aureus and V.harveyi.Scanning electron microscope results showed that after being treated with skin mucus,the morphology of S.aureus and V.harveyi appeared malform and crack,cellular contents leaked out.Meanwhile,the change in OD260 reflected that skin mucus could increase the permeability of bacterial cell memb

关 键 词：瘤背石磺 皮肤黏液 抑菌 透射电镜 

分 类 号：S917.4[农业科学—水产科学]