We conducted a study for immobilization of cellulase produced by Aspergillus tubingensis-IMMIS2 through pre-optimized solid-state fermentation of corn stover. Incredible increment in stability and catalytic activity of the immobilized cellulase was observed. Thermostability of the immobilized cellulase was increased to 82% at 75 °C as compared to that of free cellulase after 26 h of incubation. The cellulase activity was decreased after the 20th day of incubation of the both immobilized and free enzymes. Maximum cellulase activity was achieved at pH 4.5 (174 ± 0.4 U mL⁻¹ min⁻¹) and temperature 45 °C (179 ± 0.4 U mL⁻¹ min⁻¹) for xerogel matrix. The lowest K_m value was found for the enzyme immobilized on xerogel as compared to those of immobilized on calcium alginate and free enzyme. Immobilization of cellulase on calcium alginate and xerogel matrix increased tolerance capacity of the enzyme to 75–82% against different activators and/or inhibitors like EDTA, SDS, Co²⁺, Ca²⁺ and Hg²⁺. The immobilized cellulase also revealed good fruit saccharification and yielded increased juice volume and hence proved to be a suitable candidate for biotechnological and industrial applications.

中文翻译：

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海藻酸钙和干凝胶基质上的固定真菌纤维素酶

我们进行了一项研究，通过预先优化的玉米秸秆固态发酵，固定了曲霉菌-IMMIS2产生的纤维素酶。观察到固定的纤维素酶的稳定性和催化活性的增加令人难以置信。孵育26小时后，与游离纤维素酶相比，固定纤维素酶在75°C时的热稳定性提高到82％。固定酶和游离酶孵育20天后，纤维素酶活性降低。对于干凝胶基质，最大纤维素酶活性在pH 4.5（174±0.4 U mL ^-1 min ^-1）和温度45°C（179±0.4 U mL ^-1 min ^-1）时达到。最低K _m与固定在海藻酸钙和游离酶上的酶相比，发现固定在干凝胶上的酶具有更高的价值。将纤维素酶固定在藻酸钙和干凝胶基质上可使该酶对不同活化剂和/或抑制剂（如EDTA，SDS，Co 2 ⁺，Ca ²⁺和Hg ^2+）的耐受能力提高到75-82％。固定的纤维素酶还显示出良好的水果糖化性，并增加了果汁的量，因此被证明是生物技术和工业应用的合适候选者。