Interdisciplinary Program of Graduate School for Bioenergy and Biomaterials, Chonnam National University, Gwangju, 500-757, South Korea.
Bioprocess Biosyst Eng. 2012 Jan;35(1-2):29-33. doi: 10.1007/s00449-011-0630-z. Epub 2011 Sep 24.
Bacillus subtilis TD6 was isolated from Takifugu rubripes, also known as puffer fish. Cellulase from this strain was partially purified by ammonium sulphate precipitation up to 80% saturation, entrapped in calcium alginate beads, and finally characterized using CMC as the substrate. For optimization, various parameters were observed, including pH maximum, temperature maximum, sodium alginate, and calcium chloride concentration. pH maximum of the enzyme showed no changes before and after immobilization and remained stable at 6.0. The temperature maximum showed a slight increase to 60 °C. Two percent sodium alginate and a 0.15 M calcium chloride solution were the optimum conditions for acquisition of enzyme with greater stability. K (m) and V (max) values for the immobilized enzyme were slightly increased, compared with those of free enzyme, 2.9 mg/ml and 32.1 μmol/min/mL, respectively. As the purpose of immobilization, reusability and storage stability of the enzyme were also observed. Immobilized enzyme retained its activity for a longer period of time and can be reused up to four times. The storage stability of entrapped cellulase at 4 °C was found to be up to 12 days, while at 30 °C, the enzyme lost its activity within 3 days.
从东方多斑河豚中分离得到短小芽孢杆菌 TD6。该菌株的纤维素酶经硫酸铵沉淀至 80%饱和度进行部分纯化，包埋在海藻酸钠珠中，最后以 CMC 为底物进行特性分析。为优化条件，观察了各种参数，包括最适 pH 值、最适温度、海藻酸钠和氯化钙浓度。酶的最适 pH 值在固定化前后没有变化，稳定在 6.0。最适温度略有升高至 60°C。2%的海藻酸钠和 0.15 M 的氯化钙溶液是获得稳定性更高的酶的最佳条件。与游离酶相比，固定化酶的 K(m)和 V(max)值略有增加，分别为 2.9 mg/ml 和 32.1 μmol/min/mL。作为固定化的目的，还观察了酶的重复使用性和储存稳定性。固定化酶的活性保持时间更长，可重复使用多达 4 次。在 4°C 下，包埋纤维素酶的储存稳定性长达 12 天，而在 30°C 下，酶在 3 天内失去活性。
