Department of Applied Science and Technology, Environmental Management Laboratory, A.C. Tech , Anna University , Chennai 600025 , India.
Univ. Grenoble Alpes, CNRS , Grenoble INP, LGP2 , 38000 Grenoble , France.
Langmuir. 2018 Jun 5;34(22):6546-6555. doi: 10.1021/acs.langmuir.8b00976. Epub 2018 May 21.
Enzyme cocktails of reusable, highly stable cellulolytic enzymes play an inevitable role in bioconversion of biomass to biofuels economically. Cellulase, xylanase and β-1,3-glucanase bound silica-amine functionalized iron oxide magnetic nanoparticles (ISN-CLEAs) were prepared and used as the biocatalyst for the depolymerization of cellulosic biomass into monomeric sugar in the present study. The FeO-NPs and FeO@SiO-NH-NPs and ISN-CLEAs had an average hydrodynamic size of 82.2, 86.4, and 976.9 nm, respectively, which was confirmed by dynamic light scattering (DLS). About 97% of protein binding was achieved with 135 mM glutaraldehyde at 10 h of cross-linking time and successful binding was confirmed by Fourier transform infrared spectroscopy (FTIR). The ISN-CLEAs exhibited the highest thermal stability of 95% at 50 °C for 2 h and retained extended storage stability of 97% compared to 60% of its free counterpart. Besides, cross-linking allowed ISN-CLEAs reuse for at least eight consecutive cycles retaining over 70% of its initial activity. ISN-CLEAs exhibited approximately 15% increase in carbohydrate digestibility on sugar cane bagasse and eucalyptus pulp than the free enzyme.
可重复使用的、高度稳定的纤维素酶酶制剂在经济上将生物质转化为生物燃料的生物转化中发挥着不可避免的作用。本研究中，将纤维素酶、木聚糖酶和β-1,3-葡聚糖酶固定在硅烷-胺功能化的氧化铁磁性纳米粒子（ISN-CLEAs）上，用作将纤维素生物质解聚为单体糖的生物催化剂。FeO-NPs、FeO@SiO-NH-NPs 和 ISN-CLEAs 的平均水动力粒径分别为 82.2、86.4 和 976.9nm，这是通过动态光散射（DLS）证实的。用 135mM 戊二醛在交联 10 小时后实现了约 97%的蛋白结合，傅里叶变换红外光谱（FTIR）证实了成功结合。ISN-CLEAs 在 50°C 下具有最高的热稳定性，在 2 小时内保留了 95%的活性，与游离酶相比，其延长的储存稳定性保留了 97%，而不是 60%。此外，交联作用允许 ISN-CLEAs 至少重复使用 8 次，保留了其初始活性的 70%以上。ISN-CLEAs 在甘蔗渣和桉树浆上的碳水化合物消化率比游离酶提高了约 15%。
