Yaverino-Gutierrez Mario Alberto, Ascencio Jesús Jiménez, Chandel Anuj Kumar
Renewable Carbon and Biological Systems (ReCABS) Laboratory, Department of Biotechnology, Lorena School of Engineering, University of São Paulo (EEL-USP), Lorena, SP, 12602-810, Brazil.
Appl Biochem Biotechnol. 2025 Jul 2. doi: 10.1007/s12010-025-05316-y.
The efficient conversion of lignocellulosic biomass into fermentable sugars is critical for the sustainable production of biofuels and bioproducts. This study optimized mild alkaline pretreatment conditions for eucalyptus sawdust (ES) and sugarcane bagasse (SCB) using a Response Surface Methodology-Central Composite Rotational Design (RSM-CCRD). The effects of NaOH concentration, solid loading, temperature, and retention time on enzymatic hydrolysis efficiency were evaluated. Optimal pretreatment conditions (7.5% NaOH, 5% solid loading, 90 °C, 8 h) led to a tenfold increase in total reducing sugars (TRS) from ES (40.4 g/L) after 72 h, while SCB exhibited a higher hydrolysis efficiency (89.2%) and TRS (60.8 g/L) after enzymatic hydrolysis. Structural analyses using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) revealed enhanced cellulose accessibility and lignin modification in pretreated SCB, whereas ES remained more recalcitrant due to its higher lignin content. These findings demonstrate the effectiveness of mild alkaline pretreatment for SCB and highlight the need for more aggressive conditions to improve the digestibility of hardwood biomass. This study contributes to optimizing pretreatment strategies to enhance sugar release from agro-industrial residues, supporting lignocellulosic biorefinery development.
将木质纤维素生物质高效转化为可发酵糖对于生物燃料和生物产品的可持续生产至关重要。本研究采用响应面法-中心复合旋转设计（RSM-CCRD）优化了桉木锯末（ES）和甘蔗渣（SCB）的温和碱性预处理条件。评估了氢氧化钠浓度、固含量、温度和保留时间对酶水解效率的影响。最佳预处理条件（7.5%氢氧化钠、5%固含量、90°C、8小时）使ES在72小时后的总还原糖（TRS）增加了十倍（40.4克/升），而SCB在酶水解后表现出更高的水解效率（89.2%）和TRS（60.8克/升）。使用傅里叶变换红外光谱（FTIR）、X射线衍射（XRD）和扫描电子显微镜（SEM）进行的结构分析表明，预处理后的SCB中纤维素的可及性增强，木质素发生了改性，而ES由于其较高的木质素含量仍然更难降解。这些发现证明了温和碱性预处理对SCB的有效性，并强调需要更苛刻的条件来提高硬木生物质的消化率。本研究有助于优化预处理策略，以提高农业工业残渣中的糖释放量，支持木质纤维素生物精炼厂的发展。
