鱿鱼墨囊共生菌对鱿鱼墨黑色素聚合度的影响

Melanin is a kind of bio-pigment formed by multi-step oxidation and polymerization of phenols and/or indoles, which has important biological functions such as defense and protection, and its photoprotection is closely related to degree of polymerization. Squid ink sac, as a special habitat, contains a large amount of squid ink melanin. Current studies have shown that squid ink melanin is composed of secondary degradation oligomers with different molecular weights. However, there are few reports on the relationship between symbiotic microorganisms in squid ink sac and the degree of polymerization of squid ink melanin.Therefore, this project intends to take squid ink sac as the research object, and analyze the structure and composition of symbiotic microbial community of squid ink sac by means of molecular biology and microbial culture, so as to obtain the secondary biodegradable bacteria of squid ink melanin. Thereby revealing the squid the effect of commensal microbes on the degree of polymerization of squid ink melanin. The results can lay a foundation for the practical application of squid ink melanin in food, nutrition and health care, and have important economic and social significance for promoting the development of high-value utilization of processed wastes of pelagic fishery and aquatic products in China.

黑色素是一类由酚类和/或吲哚类物质经多步氧化聚合形成的生物色素，具有防御、保护等生物活性功能，其光保护作用与聚合度密切相关。鱿鱼墨囊作为一种特殊生境，其中存在大量的鱿鱼墨黑色素，当前研究表明，鱿鱼墨黑色素是由分子量不等的次生降解低聚物组成，然而，目前关于鱿鱼墨囊共生微生物与鱿鱼墨黑色素聚合度相互关系的研究鲜见报道。因此，本项目拟以北太平洋鱿鱼墨囊为研究对象，运用分子生物学和微生物培养研究手段，对鱿鱼墨囊共生微生物群落的结构组成进行分析，致力于鱿鱼墨黑色素次生降解菌的获取；并对黑色素降解菌进行全基因组测序及降解酶基因生物信息学分析，对黑色素降解相关基因的次生降解功能进行研究，从而揭示鱿鱼墨囊共生微生物对鱿鱼墨黑色素聚合度的影响。研究结果能为鱿鱼墨黑色素在食品、营养保健等领域的实际应用奠定基础，对促进我国远洋渔水产品加工废弃物的高值化利用的发展具有重要的经济和社会意义。

黑色素是一类由酚类和/或吲哚类物质经多步氧化聚合形成的生物色素，具有防御、保护、抗氧化抗炎等生物活性功能，然而在加工过程中，鱿鱼墨黑色素通常被丢弃掩埋，污染当地环境。本项目以鱿鱼墨囊为研究对象，采用传统微生物法和高通量测序法对鱿鱼墨囊共生菌的结构组成和多样性进行分析；其次结合紫外光谱、红外光谱以及扫描电子显微镜、透射电镜等技术对两种鱿鱼墨黑色素结构进行表征，并进行抗炎活性研究，此外，本项目还研究了一种快速、低成本、高通量的鱿鱼自动分类及新鲜度鉴定方法。研究结果表明：1）两种鱿鱼墨囊共生微生物有差异，但功能相近；2）两种鱿鱼墨黑色素的结构有差异，结构上的差异解释了秘鲁鱿鱼墨黑色素较真鱿鱿鱼墨黑色素更易溶。3）鱿鱼墨黑色素可以逆转DSS干预诱导的小鼠体重下降、结肠变短、出血、肿胀；以及缓解氧化应激、影响相关炎症因子表达、恢复连接蛋白表达水平、改善细胞凋亡等，进而改善小鼠肠道炎症，另外可发现，秘鲁鱿鱼墨黑色素较真鱿效果好。4）开发了一种基于改进Faster-RCNN卷积神经网络技术的鱿鱼自动分类方法，该方法在测试集上的准确率为87%，算法平均运行时间为0.144 s，此外，基于全局阈值分割法实现了鱿鱼新鲜度在线实时检测。本研究为鱿鱼墨黑色素的开发利用奠定基础，同时，实现鱿鱼品种的精确分类对于制定合理的捕捞策略、构建差异化定价体系具有十分重要的意义。