Abstract

In this study, cellulose nanocrystals (CNC) were produced from untreated and pretreated sugarcane fibers through enzymatic hydrolysis using a crude cellulolytic extract produced by the fungus Aspergillus fumigatus CCT 7873 using semi-solid fermentation (SSF). The fibers were characterized in terms of cellulose, hemicellulose, and lignin contents and crystallinity index. The CNC generated during the enzymatic hydrolysis using a sugarcane fiber pretreated with 4% NaOH and an enzymatic loading of 7.5 FPU g⁻¹ of bagasse were characterized by atomic force microscopy (AFM). The results showed that after the hydrolysis time of 48 h, spherical-like particles with a good size distribution and a mean diameter of 61 nm were obtained.

Novelty statement

In this study, we produced cellulose nanocrystals (CNC) from untreated and pretreated sugarcane fibers through enzymatic hydrolysis using a crude cellulolytic extract produced by the fungus Aspergillus fumigatus CCT 7873 using semi-solid fermentation (SSF). In fact, the main novelty of this manuscript is the fact that it accompanies the formation of CNC, by means of atomic force microscopy (AFM). It is noteworthy that there are few manuscripts with this approach in the literature. In addition, this was performed during the cultivation of a fermentation broth containing cellulases produced by an enzymatic extract of the fungus Aspergillus fumigatus CCT 7873 using SSF. Thus, CNC, a highly added value product, can be obtained from lignocellulosic residues, which is a renewable and low-cost source. The results showed that, during the cultivation, there is a variation in the size distribution of the CNC and that, for the hydrolysis time of 48 h, a good size distribution was obtained for the CNC with about 61 nm in diameter, presenting a spherical shape.

中文翻译：

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烟曲霉CCT 7873的酶提取物，用于甘蔗渣的水解和纤维素纳米晶体（CNC）的生成

摘要

在这项研究中，使用半固态发酵（SSF）由烟曲霉CCT 7873产生的粗纤维素提取物，通过酶促水解，由未经处理和经过预处理的甘蔗纤维生产纤维素纳米晶体（CNC ）。根据纤维素，半纤维素，木质素含量和结晶度表征纤维。使用原子力显微镜（AFM）对使用4％NaOH预处理的甘蔗纤维和7.5 FPU g ^-1的蔗渣进行酶水解过程中生成的CNC进行了表征。结果表明，经过48 h的水解，得到了粒径分布良好，平均粒径为61 nm的球形颗粒。

新颖性声明

在这项研究中，我们使用半固态发酵（SSF）由烟曲霉CCT 7873产生的粗纤维素分解提取物，通过酶促水解，由未经处理和经过预处理的甘蔗纤维生产了纤维素纳米晶体（CNC ）。实际上，该手稿的主要新颖之处在于它通过原子力显微镜（AFM）伴随CNC的形成。值得注意的是，文献中很少有使用这种方法的手稿。另外，这是在培养含有由真菌烟曲霉的酶提取物产生的纤维素酶的发酵液期间进行的。使用SSF的CCT 7873。因此，可以从木质纤维素残留物中获得高附加值的产品CNC，这是一种可再生的低成本来源。结果表明，在培养过程中，CNC的尺寸分布存在变化，并且在48 h的水解时间下，直径约为61 nm的CNC可获得良好的尺寸分布，呈球形形状。