Izmir Institute of Technology, Science Faculty, Department of Chemistry Gülbahçe Urla, Izmir, Turkey.
Int J Biol Macromol. 2012 Apr 1;50(3):545-51. doi: 10.1016/j.ijbiomac.2012.01.017. Epub 2012 Jan 31.
Thermoalkalophilic esterase enzyme from Balçova (Agamemnon) geothermal site were aimed to be immobilized effectively via a simple and cost-effective protocol in silicate coated Calcium alginate (Ca-alginate) beads by entrapment. The optimal immobilization conditions of enzyme in Ca-alginate beads were investigated and obtained with 2% alginate using 0.5mg/ml enzyme and 0.7 M CaCl(2) solution. In order to prevent enzyme from leaking out of the gel beads, Ca-alginate beads were then coated with silicate. Enzyme loading efficiency and immobilization yield for silicate coated beads was determined as 98.1% and 71.27%, respectively and compared with non-coated ones which were 68.5% and 45.80%, respectively. Surface morphologies, structure and elemental analysis of both silicate coated and non-coated alginate beads were also compared using Fourier Transform Infrared Spectroscopy (FT-IR) and Scanning Electron Microscope (SEM) equipped with Energy-dispersive X-ray spectroscopy (EDX). Moreover, silicate coated alginate beads enhanced reusability of esterase in continuous processes compared to non-coated beads. The hydrolytic properties of free and immobilized enzyme in terms of storage and thermal stability as well as the effects of the temperature and pH were determined. It was observed that operational, thermal and storage stabilities of the esterase were increased with immobilization.
从巴爾奇瓦（阿伽門農）地熱區域中提取的嗜堿脂肪酶，目的是通過簡單且具有成本效益的方案，在硅酸鹽包被的海藻酸鈣（Ca-海藻酸鈉）珠中被包埋而有效地固定化。研究了酶在 Ca-海藻酸鈉珠中的最佳固定化條件，並使用 2%的海藻酸鈉、0.5mg/ml 的酶和 0.7 M 的 CaCl2溶液獲得。為了防止酶從凝膠珠中滲漏出來，然後用硅酸鹽對 Ca-海藻酸鈉珠進行塗覆。硅酸鹽塗覆珠的酶載量效率和固定化收率分別為 98.1%和 71.27%，而未塗覆的分別為 68.5%和 45.80%。還使用傅立葉變換紅外光譜（FT-IR）和掃描電子顯微鏡（SEM）配備能量色散 X 射線光譜（EDX）比較了硅酸鹽塗覆和未塗覆的海藻酸鈉珠的表面形貌、結構和元素分析。此外，與未塗覆的珠相比，硅酸鹽塗覆的海藻酸鈉珠在連續過程中提高了脂肪酶的重復使用性。測定了自由酶和固定化酶在儲存和熱穩定性方面以及溫度和 pH 值的影響下的水解特性。觀察到酶的操作、熱和儲存穩定性隨著固定化而提高。
