Department of Chemical Engineering, Institute of Chemical Technology, Matunga, Mumbai 400019, India.
Department of Chemical Engineering, Institute of Chemical Technology, Matunga, Mumbai 400019, India.
Bioresour Technol. 2017 Sep;239:117-126. doi: 10.1016/j.biortech.2017.04.096. Epub 2017 Apr 27.
In the present work, effect of low power, low frequency ultrasound on cellulase immobilized magnetic nanoparticles (cellulase@MNPs) was studied. To gain maximum activity recovery in cellulase@MNPs various parameters viz. ratio of MNPs:cellulase, concentration of glutaraldehyde and cross-linking time were optimized. The influence of ultrasonic power on cellulase@MNPs was studied. Under ultrasonic conditions at 24kHz, 6W power, and 6min of incubation time there was almost 3.6 fold increased in the catalytic activity of immobilized cellulase over the control. Results also indicated that there was improvement in pH and temperature stability of cellulase@MNPs. Furthermore, thermal deactivation energy required was more in cellulase@MNPs than that of the free cellulase. Secondary structural analysis revealed that there were conformational changes in free cellulase and cellulase@MNPs before and after sonication which might be responsible for enhanced activity after ultrasonication. Finally, the influence of ultrasound and cellulase@MNPs for biomass hydrolysis was studied.
本工作研究了低功率、低频超声对固定化纤维素酶磁性纳米粒子（cellulase@MNPs）的影响。为了获得纤维素酶@MNPs 的最大活性回收，优化了各种参数，如 MNPs:纤维素酶的比例、戊二醛的浓度和交联时间。研究了超声功率对纤维素酶@MNPs 的影响。在 24kHz、6W 功率和 6min 的孵育时间的超声条件下，固定化纤维素酶的催化活性比对照提高了近 3.6 倍。结果还表明，纤维素酶@MNPs 的 pH 和温度稳定性得到了提高。此外，纤维素酶@MNPs 的热失活动力学能比游离纤维素酶的高。二级结构分析表明，游离纤维素酶和超声前后的纤维素酶@MNPs 都发生了构象变化，这可能是超声后活性增强的原因。最后，研究了超声和纤维素酶@MNPs 对生物质水解的影响。
