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为了深入了解菊芋茎秆用于生物能源转化的潜力,在对菊芋茎秆的全秆、韧皮以及髓芯的组成分析基础上,采用不同浓度的Na OH在121℃对菊芋茎秆进行预处理,并对预处理后的茎秆进行酶水解。结果表明:菊芋茎秆具有较高木质素含量(32.0%),且韧皮中木质素含量最高;茎秆中碳水化合物总含量与传统农作物秸秆相当,但纤维素含量相对较高(40.5%),半纤维含量相对较低(19.6%)。经不同浓度Na OH预处理后,相对于未处理茎秆,全秆、韧皮以及髓芯中木质素含量分别降低13.1%–13.4%、8.3%–13.5%和19.9%–27.2%,半纤维素含量分别降低了87.8%–96.9%、87.6%–95.0%和74.0%–90.2%。纤维素含量在全秆、韧皮和髓芯中相应增加了56.5%–60.2%、52.2%–55.4%和62.7%–73.2%。酶水解的结果显示,增加预处理过程中Na OH的浓度,全秆和韧皮的水解率可被提高2.3–2.6倍和10.3–18.5倍。虽然热Na OH预处理可以有效地改善髓芯水解性能,但经过高浓度的Na OH(2.0 mol/L)预处理,髓芯的水解性能下降明显。由此可见,菊芋用于生物能源转化技术中,热碱法可较好地适用于菊芋秸秆预处理。提高碱浓度,有利于半纤维素和木质素的去除,并实现酶水解糖化产率的提高。但鉴于碱浓度过高会造成髓芯糖产率降低,热碱预处理菊芋秸秆工艺条件需进一步优化。
In order to further understand the potential of Jerusalem artichoke stalks for bioenergy conversion, based on the analysis of composition of stalks, phloem and core of Jerusalem artichoke stalks, the stalks of Jerusalem artichoke were pretreated with Na OH at 121 ℃ , And the pretreated stem was enzymatically hydrolyzed. The results showed that Jerusalem artichoke stalk had the highest content of lignin (32.0%) and the highest content of lignin in the bast; the total content of carbohydrate in the stalk was similar to that of the traditional crop straw, but the cellulose content was relatively high (40.5% , Semi-fiber content is relatively low (19.6%). Compared with untreated stems, the content of lignin in whole stalks, phloem and pulp core decreased by 13.1% -13.4%, 8.3% -13.5% and 19.9% -27.2%, respectively, after pretreatment with different concentrations of Na-OH. The content of hemicellulose The content of chlorophyll decreased by 87.8% -96.9%, 87.6% -95.0% and 74.0% -90.2% respectively. Cellulose content increased by 56.5% -60.2%, 52.2% -55.4% and 62.7% -73.2% in whole stalk, bast and core respectively. The results of enzymatic hydrolysis showed that the hydrolysis rate of whole stalks and bast was increased by 2.3-2.6 times and 10.3-18.5 times when Na OH concentration was increased during pretreatment. Although thermal NaOH pretreatment can effectively improve the core hydrolysis, but after high concentration of NaOH (2.0 mol / L) pretreatment, the core hydrolysis decreased significantly. Thus, Jerusalem artichoke for biological energy conversion technology, the hot alkali method can be better applied to Jerusalem artichoke straw pretreatment. Increasing the alkali concentration is conducive to the removal of hemicellulose and lignin, and to improve the yield of enzymatic hydrolysis and saccharification. However, in view of the high alkali concentration, the yield of saponin will decrease, and the technological conditions of hot alkali pretreatment of Jerusalem artichoke straw need to be further optimized.