Carboxylated cellulose nanocrystals (cCNCs) can be prepared directly from biomass in a one-step ammonium persulfate (APS) oxidation. However, the cellulose in the biomass is not fully utilized because APS oxidation degrades the cellulose amorphous regions. In this paper, to improve cellulose utilization rate, a two-step method (enzymatic pre-hydrolysis and APS oxidation) was developed to co-produce fermentable sugar and cCNCs from xylooligosaccharides manufacturing waste residue (XOR) of corncob. Enzymatic pre-hydrolysis produced 26.1 g of glucose per 100 g of XOR with a cellulase loading of 5 FPU/g cellulose in 24 h. Subsequent oxidation produced 22.9 g cCNCs with 0.5 M APS in 8 h. In contrast, the one-step APS method only produced 28.3 g cCNCs per 100 g of XOR. The total cellulose utilization rate by the two-step method increased by 73 % compared to the one-step APS method. Structural characteristics of cCNCs prepared by the two-step method were slightly different from those of the one-step method, but good properties were maintained. Therefore, the co-production method could prepare glucose and cCNCs with stable properties from XOR with a greatly improved cellulose utilization rate.

中文翻译：

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通过低酶预水解和过硫酸盐氧化，从富含纤维素的生物质废渣中高效联产葡萄糖和羧化纤维素纳米晶体


羧化纤维素纳米晶体 (cCNC) 可以通过一步过硫酸铵 (APS) 氧化直接从生物质制备。然而，生物质中的纤维素没有得到充分利用，因为 APS 氧化会降解纤维素无定形区域。本文为提高纤维素利用率，开发了一种两步法（酶预水解和APS氧化），以玉米芯低聚木糖生产废渣（XOR）为原料，联产可发酵糖和cCNC。酶促预水解在 24 小时内每 100 g XOR 产生 26.1 g 葡萄糖，纤维素酶负载量为 5 FPU/g 纤维素。随后的氧化在 8 小时内产生了 22.9 g cCNC，其 APS 为 0.5 M。相比之下，一步 APS 方法每 100 g XOR 仅产生 28.3 g cCNC。两步法的纤维素总利用率比一步APS法提高了73%。两步法制备的cCNCs的结构特征与一步法略有不同，但保持了良好的性能。因此，联产方法可以通过XOR制备性质稳定的葡萄糖和cCNC，并大大提高纤维素利用率。