Abstract：
Aim of present study was to develop biological catalysts of L-arabinose isomerase (L-AI) by immobilizing on four different supports such as multiwalled carbon nanotube (MWCNT), graphene oxide (GOx), Santa Barbara Amorphous (SBA-15) and mobile composite matter (MCM-41). Also, comparative analysis of the developed catalysts was performed to evolve the best in terms of transformation efficiency for D-tagatose production. The developed nano-enzyme conjugates (NECs) were characterized using the high resolution transmission electron microscopy (HR-TEM) and elemental analysis was performed by energy dispersive X-ray spectroscopy (EDS). The functional groups were investigated by Fourier transform infra red spectroscopy. Also, the thermo gravimetric analysis (TGA) was employed to plot a thermal degradation weight loss profile of NECs. The conjugated L-AI with MWCNT and GOx were found to be more promising immobilized catalysts due to their ability to provide more surface area. Conversion of D-Galactose to D-Tagatose at moderate temperature and pH was observed to attain the equilibrium level of transformation (~50%). On the contrary, NECs prepared using SBA-15 and MCM-41 as support matrix were unable to reach the equilibrium level of conversion. Additionally, the developed NECs were suitable for reuse in multiple batch cycles. Thus, promising nanotechnology coupled with biocatalysis made the transformation of D-Galactose into D-tagatose more economically sustainable.
摘要：
本研究的目的是通过将L-阿拉伯糖异构酶（L-AI）固定在多壁碳纳米管（MWCNT）等四种不同的载体上来开发生物催化剂，氧化石墨烯(GOx),圣巴巴拉无定形（SBA-15）和移动复合物质（MCM-41）。此外，对开发的催化剂进行了比较分析，以在D-塔格糖生产的转化效率方面获得最佳。使用高分辨率透射电子显微镜（HR-TEM）对开发的纳米酶缀合物（NEC）进行表征，并通过能量色散X射线光谱（EDS）进行元素分析。通过傅里叶变换红外光谱法研究官能团。此外，热重分析（TGA）用于绘制NEC的热降解失重曲线。发现具有MWCNT和GOx的缀合的L-Al是更有前途的固定化催化剂,因为它们能够提供更大的表面积。观察到在中等温度和pH下D-半乳糖向D-塔格糖的转化达到转化的平衡水平(~50%)。相反,使用SBA-15和MCM-41作为支持基质制备的NEC无法达到平衡的转化水平。此外,开发的NEC适合在多个批次循环中重复使用。因此，有前途的纳米技术与生物催化相结合，使D-半乳糖转化为D-塔格糖更具经济可持续性。
