Qi Xuemin, Chu Jie, Jia Liangliang, Kumar Anuj
College of Forestry, Northwest A&F University, 3 Taicheng Road, Yangling 712100, China.
Natural Resources Institute Finland (Luke), Production Systems, Tietotie 2, FI-02150 Espoo, Finland.
Materials (Basel). 2019 Aug 12;12(16):2570. doi: 10.3390/ma12162570.
In the present study, three pretreatments of sodium hydroxide (NaOH), sulfuric acid (HSO), and glycerin were employed with bamboo fibers at two different temperatures of 117 °C and 135 °C, respectively. The chemical composition and structural characterization of the pretreated bamboo fibers were comparatively studied using spectroscopic and wet chemistry methods. Furthermore, the comparative hydrolysis behaviors of pretreated bamboo were studied due to the synergistic interaction between cellulases and xylanase. The NaOH treatment increased the holocellulose contents to 87.4%, and the mean diameter of the cellulose fibers decreased from 50 ± 5 µm (raw fiber bundles) to 5 ± 2 µm. The lignin content and the degree of cellulose polymerization both decreased, while the crystallinity index of cellulose and thermostability increased. The hydrolysis yields of NaOH pretreated bamboo at 135 °C increased from 84.2% to 98.1% after a supplement of 0.5 cellulose to 1 mg protein/g dry xylan. The NaOH pretreatment achieved optimal enzymatic digestibility, particularly at higher temperatures as indicated by the results.
在本研究中，分别在117℃和135℃这两种不同温度下，对竹纤维采用了氢氧化钠（NaOH）、硫酸（H₂SO₄）和甘油三种预处理方法。使用光谱学和湿化学方法对预处理后的竹纤维的化学成分和结构特征进行了比较研究。此外，由于纤维素酶和木聚糖酶之间的协同相互作用，研究了预处理后竹子的比较水解行为。NaOH处理使全纤维素含量增加到87.4%，纤维素纤维的平均直径从50±5μm（原纤维束）降至5±2μm。木质素含量和纤维素聚合度均降低，而纤维素的结晶度指数和热稳定性增加。在每克干木聚糖补充0.5纤维素至1毫克蛋白质后，135℃下NaOH预处理竹子的水解产率从84.2%提高到98.1%。结果表明，NaOH预处理实现了最佳的酶消化率，特别是在较高温度下。
