Cuttlebone modified chitosan used as immobilized trypsin carrier and degradation of bovine hemoglobin

Cuttlebone (CFB) is a food waste and primarily composed of calcium carbonate. In this study, the chitosan modified CFB (chitosan@CFB) was prepared by the CFB particle coated with chitosan and then employed as an eco-friendly carrier for trypsin immobilization. The immobilized trypsin (trypsin@chitosan@CFB) was characterized by scanning electron microscopy. The optimal pH of trypsin@chitosan@CFB was 9.0 and the optimal temperature was 37 °C. The trypsin@chitosan@CFB exhibited excellent temperature, pH, storage stability, and reusability. The <i>K</i>m of the trypsin@chitosan@CFB was 0.64 mM when casein used as substrate. The trypsin@chitosan@CFB was used for bovine hemoglobin degradation and the result was analyzed by SDS-PAGE. The trypsin@chitosan@CFB demonstrated preferably potential for industrial applications.

乌贼骨（Cuttlebone, CFB）是一种食品废弃物，其主要成分为碳酸钙。本研究中，通过壳聚糖包覆乌贼骨颗粒制备得到壳聚糖改性乌贼骨（chitosan@CFB），并将其作为一种环保型载体用于胰蛋白酶固定化。本研究采用扫描电子显微镜对固定化胰蛋白酶（trypsin@chitosan@CFB）进行了表征。该固定化胰蛋白酶的最适pH为9.0，最适反应温度为37℃。该固定化胰蛋白酶展现出优异的温度稳定性、pH稳定性、储存稳定性及重复使用性能。以酪蛋白为底物时，该固定化胰蛋白酶的米氏常数（Km）为0.64 mM。将该固定化胰蛋白酶应用于牛血红蛋白的降解实验，并通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）对降解结果进行分析。该固定化胰蛋白酶展现出良好的工业应用潜力。