Isolation of Hemicellulose from Corn Fiber by Alkaline Hydrogen Peroxide Extraction

For the first time, alkaline hydrogen peroxide (AHP) extraction conditions were used to isolate hemicellulose (arabinoxylan) from destarched corn fiber. Yields of the water-soluble hemicellulose B ranged from 35% (24 hr extraction at 25°C) to 42% (2 hr extraction at 60°C). The hemicellulose B resulting from the 2 hr extraction (pH 11.5) was off-white in color, and a very low proportion (1.7%) of water-insoluble hemicellulose A was extracted. AHP treatment caused delignification and facilitated the alkaline extraction of hemicellulose from the lignocellulosic fiber matrix. In the absence of H₂O₂, yields were reduced by more than one-third when using otherwise identical extraction conditions of time, temperature and pH. In the standard protocol, corn fiber, NaOH solution, and H₂O₂ were mixed in a 1:25:0.25 (w/v/w) ratio. Extractions were conducted at pH 11.5 at 25°C or 60°C. The pH was adjusted to 11.5 by addition of NaOH at ambient and elevated temperatures. The optimum hemicellulose yield (51.3%; dry, starch-free basis) was obtained when the pH was increased to 12.5 for the final one-half of the extraction period. Products obtained after extraction at pH values greater than 11.5 were tan in color, however, and the goal of the research has been to isolate white hemicellulose B and then evaluate its properties. Under most conditions, the yields ofhemicellulose B, potentially the most useful form for food and industrial applications, exceeded those of hemicellulose A by more than 10-fold. The hemicellulose B products were lighter in color than those obtained using traditional alkaline extraction conditions of refluxing with calcium or sodium hydroxide. Steps prior to extractions with alkaline H₂O₂, such as grinding to 20 mesh and extracting with azeotropic toluene-ethanol, were found to be unnecessary.     

TRANSFORMATION OF SUGARS WHEN RYE HEMICELLULOSE LABELLED WITH 14C DECOMPOSES IN SOIL

Incubation of soil with ¹⁴C hemicellulose from rye straw for 448 days resulted in the evolution of about 70 per cent of the substrate as CO₂. The two major sugar components of the hemicellulose, xylose (50 per cent) and arabinose (5 per cent), were almost completely decomposed. After 56 days only 5 per cent of the xylose remained and after 448 days only 1-2 per cent. Similar results were obtained for soil derived from either granitic or basic igneous parent material. Almost 4 per cent of the hemicellulose was transformed to glucose and I per cent to mannose during the first 14 days of incubation. Fine grinding of 14C rye straw increased the extent of its decomposition on incubation but after 448 days 20 per cent of both its xylose and arabinose remained. It is suggested that the isolated hemicellulose is decomposed faster because it has been made water soluble.     

利用近红外光谱测定玉米非淀粉组分中纤维素及半纤维素含量

玉米非淀粉组分是可再生的生物质资源,为实现玉米皮渣中纤维素及半纤维含量的快速检测,该研究以偏最小二乘法(PLS)建立数学模型,探讨一阶导数及二阶导数平滑等预处理对建模的影响,建立玉米皮渣中纤维素及半纤维素近红外分析模型.研究结果表明,纤维素模型的定标集和验证集相关系数为0.9806和0.9799,定标集标准偏差(SEE...     

根系主要成分含量对根系固土效能的影响

选取中国北方两种常见树种油松(Pinus tabulaeformis)和元宝枫(Acer truncatum),对这两种树0.2~6mm直径的根系直径、根系抗拉强度、整根的根土复合体强度、根系3种主要成分含量(纤维素含量、半纤维素含量与木质素含量)进行测定。结果表明,随着根系直径的增加,植物根系半纤维素含量增高,纤维素含量与木质素含量降低,从而植物的抗拉强度降低。植物根系抗拉强度与纤维素含量、木质素含量成正相关关系,与半纤维素含量成负相关关系。因此,在排除根系结构影响的前提下,植物根系纤维素含量与木质素含量是导致不同植物种固土效果差异的直接原因。     

金属阳离子促进酸预处理玉米秸秆效果

0.01%稀硫酸辅助超声波洗涤玉米秸秆可除去大量K、Ca、Mg及P元素。洗涤后秸秆用0.1%硫酸预处理时,硫酸中添加金属氯盐预处理时半纤维素降解率达37%,预处理渣的酶解率最高达23%;经洗涤的秸秆在未添加金属氯盐时,其值分别为17%和 12%。添加金属氯盐使反应体系溶液pH值降低,但添加与金属氯盐溶液的pH值相同的纯硫酸预处理经洗涤的玉米秸秆时,半纤维素降解率为19%,低于添加金属氯盐预处理的半纤维素降解率37%。几种氯盐中,FeCl3促进酸预处理半纤维素降解率高于其他几种。可知,金属氯盐特别是氯化铁能促进稀硫酸预处理玉米秸秆半纤维素降解率,且pH值降低不是引起预处理效率提高的关键原因。     

Cell wall polysaccharide chemistry of peach genotypes with contrasted textures and other fruit traits

Cell wall composition, pectin, and hemicellulose fine structure variation were assessed in peach and related genotypes with contrasted texture and fruit shape. Cell walls were prepared from four commercial peaches, eight genotypes from the Jalousia × Fantasia peach cross, and six genotypes from the Earlygold peach × Texas almond cross. Sugar composition was determined chemically while fine structure of homogalacturonan pectin and xyloglucan hemicellulose were assessed by coupling pectin lyase and glucanase degradation, respectively, with MALDI-TOF MS analysis of the degradation products. The results indicate clear compositional and structural differences between the parents and their related genotypes on the basis of pectin versus cellulose/hemicellulose content and on the fine structure of homogalacturonan and xyloglucan. A relation between methyl- and acetyl-esterification of pectin with fruit shape is revealed in the Fantasia × Jalousia peach genotypes.     

半纤维素分解菌群HMC的微生物群落结构及功能

为明确半纤维素分解菌群HMC（hemicellulolytic microbial consortium）的微生物群落结构及其在半纤维素降解中的潜在功能;该研究测定了其在降解半纤维素主链木聚糖及玉米芯的典型理化指标,并利用16S rDNA测序技术及生物信息学手段对其微生物群落结构及功能注释进行了宏基因组学分析。结果表明,HMC在7d内能高效降解木聚糖和玉米芯,降解率达80%,木聚糖降解产生的高值产物包括还原糖、甲酸、乳酸及乙酸,最高浓度分别为1.30、0.50、1.19与1.23 mg/mL,HMC降解玉米芯时可累积挥发性脂肪酸浓度高达3.54 mg/mL。HMC是由厚壁菌门Firmicutes的多个属的微生物组成的复合微生物菌群,宏基因组分析揭示了HMC在木聚糖降解过程中的关键碳水化合物活性酶系;HMC的半纤维素降解酶系完整,包括19个木聚糖分解及下游产物代谢相关的酶;同时涵盖了乙酸、乳酸等半纤维素关键分解产物代谢相关的通路。HMC蕴含半纤维素及玉米芯高值生物转化的潜力,该研究为深入探究半纤维素在生物降解应用中的分子机制提供了重要线索,有助于推动天然半纤维素生物降解技术的发展。     

玉米叶片纤维素含量与冠层光谱特征的研究

以株型相近的高赖氨酸玉米“中单9409”、粮饲兼用型玉米“中原单32”和高油玉米“高油115”为供试材料,研究了不同生育时期和冠层中不同高度叶片中纤维素、半纤维素含量的差异及其冠层水平的光谱响应。结果表明：在相同栽培密度和施肥水平下,不同品玉米品种叶片的纤维素、半纤维素含量存在差异,其中以中、上层叶片相差较大,不同品种间同层叶片纤维素含量相差可达34.9%,下层叶片相差较小。通过对同步获取的冠层近红外光谱与叶片中纤维素、半纤维素含量进行相关分析,分别筛选出1420、1450、1490、2100和2270 nm可作为反演纤维素含量的特征波长;而2270、2280和2340 nm可作为反演半纤维素含量的特征波长,达到了显著或极显著水平。     

城市污泥与调理剂混合堆肥过程中有机质组分的变化

【目的】研究城市污泥堆肥过程中各项有机质组分及碳、 氮在堆肥过程中的形成与转化,以期改善堆肥的生物有效性,促进其土地利用。【方法】在工厂规模化下,以城市污泥、 蘑菇渣锯末以及返混料按照6∶3∶1的质量比混合形成堆肥物料,辅以强制通风措施和翻抛,进行为期18 d的高温堆肥试验。堆肥期间定期采样,测定指标包括温度、 C/N值、 pH、 含水率、 有机质降解率、 水溶性组分、 半纤维素、 纤维素和木质素,研究堆肥期间不同阶段堆肥物料中有机质组分的动态变化。【结果】堆体温度随着发酵时间的延长呈现先升高后降低的趋势,最高温度达到71.3℃; 含水率由60.7%降低到51.4%,pH呈现先升高后降低的趋势,总体处于6.0~7.5之间; 总有机碳含量持续下降,氮素含量表现为高温期持续下降随后呈上升的趋势; 初始阶段,堆肥物料中四种成分含量分布为: 水溶性组分纤维素半纤维素木质素,至堆肥结束变化为: 纤维素水溶性组分木质素半纤维素,经过堆肥之后水溶性组分及半纤维素含量分别由39.5%和20.1%下降为27.9%和14.4%,纤维素含量由初始的21.8%上升至29.5%,木质素含量相对稳定不变。物料经过堆肥化处理后达到腐熟标准,水溶性组分和半纤维素含量分别降低了38.6%和38.8%,纤维素和木质素含量在高温期分别降解了11.7%和18.5%; 物料总量降低了9.8%。水溶性组分的主要降解阶段为高温期,期间降解部分占总降解量的65.5%; 半纤维素的主要降解阶段为稳定期,稳定期降解部分占总降解量的69.1%,且有继续降解的趋势; 纤维素和木质素仅在高温期有少量降解; 氮素则表现为高温期铵态氮的损失及稳定期硝态氮的积累。【结论】堆肥化处理在实现污泥减量化基础上,污泥中有机质得到了稳定化,有利于城市污泥的土地利用。     

水稻镉安全材料分蘖期根部镉积累分布特征

【目的】镉 (Cd) 低积累作物的培育和应用是减少土壤中Cd通过食物链危害人体健康的重要途径。通过研究Cd处理下水稻分蘖期根部Cd的积累分布特征,揭示水稻Cd安全材料根部Cd的固持机理,为水稻Cd安全品种的培育提供理论依据。【方法】以水稻Cd安全材料D62B为供试材料,普通材料Luhui17为对照,进行水培试验。水稻秧苗于三叶一心时移栽至盆中 (40 cm × 60 cm × 15 cm),以CdCl₂·2.5H₂O加入营养液,设0 (CK)、0.5 (Cd0.5)、1.0 (Cd1)、2.0 (Cd2) mg/L 4个Cd浓度处理,30天后收获,分为根和地上部测定其Cd全量。采用化学试剂逐步提取法和差速离心法分别测定根部Cd化学形态和亚细胞分布特征,并进一步结合细胞壁多糖,研究其对Cd的响应特征。【结果】1) Cd处理下D62B各部位Cd含量显著低于Luhui17,转移系数较小,其根部Cd向地上部转移较少。2) 随Cd处理浓度升高D62B根部水提取态Cd分配比例降低,盐酸提取态Cd、残渣态Cd分配比例升高,Cd移动性减弱。D62B根部Cd以氯化钠提取态为主 (48.9%～52.1%),高浓度Cd处理 (2.0 mg/L) 下其分配比例是Luhui17的1.11倍,水提取态是Luhui17的82.3%,其根中Cd的移动性弱于普通材料。3) D62B根部Cd主要分布于可溶部分和细胞壁,其中细胞壁Cd分配比例为38.6%～41.8%,高于Luhui17。随Cd处理浓度升高,D62B根细胞壁Cd分配比例降幅小于Luhui17,其细胞壁对Cd的固持作用有限但强于普通材料。4) D62B根细胞壁半纤维素1的Cd含量是果胶的7.74～8.40倍,Cd主要与细胞壁中半纤维素1结合。半纤维素1 Cd含量随Cd处理浓度升高而显著增加,2.0 mg/L Cd处理下D62B和Luhui17半纤维素1单位总糖Cd结合量较1.0 mg/L Cd处理分别增加32.6%、11.2%,D62B根细胞壁半纤维素1的Cd结合能力强于Luhui17。【结论】水稻Cd安全材料D62B各部位Cd含量低于Luhui17,其转移系数较小。D62B根中Cd主要为氯化钠提取态,随Cd处理浓度升高,根部Cd向移动性较弱的化学形态转化。D62B根细胞壁中Cd主要与半纤维素1结合,由于其Cd结合能力较强,D62B根细胞壁对Cd的固持作用强于普通材料。因此,D62B对Cd的转移能力弱于普通材料,是其籽粒Cd安全的重要原因。     

Solid-state selective (13)C excitation and spin diffusion NMR to resolve spatial dimensions in plant cell walls

The average spatial dimensions between major biopolymers within the plant cell wall can be resolved using a solid-state NMR technique referred to as a (13)C cross-polarization (CP) SELDOM (selectively by destruction of magnetization) with a mixing time delay for spin diffusion. Selective excitation of specific aromatic lignin carbons indicates that lignin is in close proximity to hemicellulose followed by amorphous and finally crystalline cellulose. (13)C spin diffusion time constants (T(SD)) were extracted using a two-site spin diffusion theory developed for (13)C nuclei under magic angle spinning (MAS) conditions. These time constants were then used to calculate an average lower-limit spin diffusion length between chemical groups within the plant cell wall. The results on untreated (13)C enriched corn stover stem reveal that the lignin carbons are, on average, located at distances ～0.7-2.0 nm from the carbons in hemicellulose and cellulose, whereas the pretreated material had larger separations.     

Changes in Cell Wall Polysaccharides and Hydroxycinnamates in Wheat Roots by Aluminum Stress at Higher Calcium Supply

The present study was conducted to investigate the cell-wall polysaccharides and hydroxycinnamates in wheat plants (Triticum aestivum L.) under aluminum (Al) stress at a higher level of calcium (Ca) supply. Seedlings were grown in nutrient solution for 7 d and then subjected to treatment solutions containing Al (0 or 100 μM) and Ca (0 or 2500 μM) in a 500 μM CaCl ₂ solution at pH 4.5 for 8 d. Calcium treatment (2500 μM) improved root growth significantly under Al-stress conditions. The contents of pectin and hemicellulose in roots were increased under Al-stress conditions, and this increase was conspicuous in the hemicellulosic fraction. The increase in the hemicellulose was attributed to increases in arabinose, xylose, and glucose in neutral sugars. High Ca treatment decreased these contents in Al-stressed cell walls. Aluminum treatment increased the content of ferulic acid, whereas Ca treatment with Al reduced the content. These results suggest that Al may modify the mechanical properties of cell-wall polysaccharides by enhancing the synthesis of arabinoxylan, β-glucan, and ferulic acid in the cell wall. High Ca treatment may maintain the normal synthesis of these materials even under Al-stress conditions.     

Fractionation of flax shives by water and aqueous ammonia treatment in a pressurized low-polarity water extractor

Fractionation of flax shives into cellulose, hemicellulose, and lignin with a two-stage extraction process using water and aqueous ammonia was carried out in a pressurized low-polarity water extractor operated at different temperatures, flow rates, and ammonia concentrations. During the first stage with water, 84% of hemicellulose and 32% of lignin were removed at 190 degrees C at a flow rate of 1.5 mL/min for 30 min. During the second stage with aqueous ammonia, more than 77% of the lignin was removed, and hemicellulose removal reached 95% at 200 degrees C at a flow rate of 0.5 mL/min and with a solvent/feed ratio of 40 mL/g. The temperature and flow rate had a significant effect on lignin removal. The impact of additives (anthraquinone and hydrogen peroxide) and modifications (overnight soaking, reduced particle size, and elevated temperature) on lignin extraction was also studied. The combination of higher temperatures and reduced particle sizes resulted in enhanced lignin extraction. The extraction profiles of free phenolics (vanillin, acetovanillone, and vanillic acid) during the two-stage processing were monitored and compared with those of lignin.     

Postharvest changes in white asparagus cell wall during refrigerated storage.

The postharvest changes of the white asparagus cell wall have been studied in relation to the toughening process along the length of a spear that was divided into three sections: apical, middle, and basal. Polysaccharides underwent significant turnover during storage. Uronic acid concentration decreased in all sections and in almost all polysaccharide fractions, while neutral sugars increased very slightly in the apical section, decreased in the middle, and increased in the basal one. Xylose, glucose, and galactose are the main neutral sugars implicated in the turnover; xylose accumulated in the hemicellulose fractions of the middle and basal sections, glucose decreased in the hemicellulose and cellulose fractions of the middle section and increased in the cellulose fraction of the basal one, and galactose disappeared mostly from the cellulose fractions of the three sections. Lignin increased most in the middle section and least in the basal one. No increase was detected in the apical one. No important increases of wall phenolics were detected in any part of the spear. The hardening process was limited only to the basal section.     

化学预处理提高酒糟生物质酶解糖化效果

为促进酒糟生物质的酶解糖化,筛选适宜的预处理方法,以脱除木质素,提高综纤维素（纤维素和半纤维素之和）保留率为目标,研究比较了酸-超声波耦合（ultrasound-assisted acid pretreatment,UAAP）、液氨（pretreatment by soaking in aqueous ammonia,PSAA）、碱性双氧水（alkaline hydrogen peroxide pretreatment,AHPP）和酸性亚硫酸氢盐（bisulfite pretreatment,BP）4种预处理法对酒糟化学组分、结构特性和酶解得率的影响。结果表明,与其余3种方法相比,BP法处理后酒糟的纤维素和半纤维素保留率最高,分别为84.59%和84.87%,即综纤维素保留率为84.68%。与未处理酒糟（unpretreatment,UP）相比,4种方法预处理后酒糟的综纤维素酶解得率分别提高了49.12%（酸-超声波,UAAP）、55.48%（液氨,PASS）、92.79%（碱性双氧水,AHPP）和99.15%（酸性亚硫酸氢盐,BP）,其中BP法对酒糟酶解糖化的促进作用最有效。扫描电镜（scanning electron microscope,SEM）和X-衍射（X-ray differaction,XRD）结果显示,酒糟经不同方法预处理后表观结构发生了明显变化,木质纤维网络结构遭到破坏,表面呈现无规则或形状各异的膨松状态,沟壑明显,孔隙率增加,比表面积增大,有利于提高水解酶的可及性。化学组分和结构特性的变化说明酒糟的酶解得率与综纤维素的保留、木质素的去除、表面微观形貌变化以及纤维素结晶度等因素直接相关。总之,酸性亚硫酸氢盐（BP）法是适用于酒糟生物质糖化预处理的一种有效可行方法。     

Potential of Near- and Mid-infrared Spectroscopy in Biofuel Production

For many decades, near-infrared spectroscopy (NIRS) has been used to determine the composition of animal feedstuffs and grains. More recently, mid-infrared spectroscopy (mid-IR) has also been examined for similar determinations. These spectroscopic methods offer the potential for rapid and accurate determination of organic constituents, such as fiber components and protein, of forages, by-products, and grains at reduced cost and greatly increased speed (minutes instead of hours or days). Because they are nonchemical in nature, they result in a large reduction (90% or more) in the chemical wastes associated with standard chemical-based assay methods. The same components of interest for biofuel production (cellulose, hemicellulose, lignin, starch, protein, oil, etc.) are those that have already been determined by NIRS/mid-IR for evaluating grains and animal feedstuffs. Therefore, these techniques would appear to be a natural match for evaluating feedstocks for biofuels, and the literature shows that efforts in this direction are being successfully tested and instituted. For this discussion, an overview of where such efforts are and the potential for NIRS/mid-IR in producing biofuels will be covered. For example, while there are similarities between the needs of the biofuels industry and the analysis of animal feedstuffs, there are also both practical and technical differences between the two that will likely impact how NIRS/mid-IR is developed for biofuels. As an example, grain analysis for protein is performed on a large scale by government agencies such as the Canadian Grain Commission and U.S. Grain Inspection Service, while at least in the United States, animal feedstuff analysis is performed by state or independent laboratories for individual farmers. For biofuels, this might well result in most analysis being performed by the large corporations converting the feedstocks to biofuels, as opposed to the individual producer having analysis performed at an independent laboratory. Similarly for animal feedstuffs, measurements of fiber (neutral detergent fiber or NDF, acid detergent fiber or ADF, and lignin) and protein are carried out. These fiber measurements often consist of more than one type of fiber component with some being computed by difference (hemicellulose = NDF – ADF) and are empirical at best. Whether such empirical estimates will be sufficient for assessing biofuels or whether new spectroscopic methods for directly measuring the components of interest (cellulose, etc.) will need to be developed is a question to be answered when components other than starch for ethanol or oil for biodiesel become common.     

Pretreatment and Enzymatic Hydrolysis of Sorghum Bran

Sorghum bran has potential to serve as a low‐cost feedstock for production of fuel ethanol. Sorghum bran from a decortication process (10%) was used for this study. The approximate chemical composition of sorghum bran was 30% starch, 18% hemicellulose, 11% cellulose, 11% protein, 10% crude fat, and 3% ash. The objective of this research was to evaluate the effectiveness of selected pretreatment methods such as hot water, starch degradation, dilute acid hydrolysis, and combination of those methods on enzymatic hydrolysis of sorghum bran. Methods for pretreatment and enzymatic hydrolysis of sorghum bran involved hot water treatment (10% solid, w/v) at 130°C for 20 min, acid hydrolysis (H₂SO₄), starch degradation, and enzymatic hydrolysis (60 hr, 50°C, 0.9%, v/v) with commercial cellulase and hemicellulose enzymes. Total sugar yield by using enzymatic hydrolysis alone was 9%, obtained from 60 hr of enzyme hydrolysis. Hot water treatment facilitated and increased access of the enzymes to hemicellulose and cellulose, improving total sugar yield up to 34%. Using a combination of starch degradation, optimum hot water treatment, and optimum enzymatic hydrolysis resulted in maximum total sugar yield of up to 75%.     

乙二醇-氯化铁预处理对棉秆酶水解效率的影响

为提高棉秆的纤维素酶水解效率,该研究以乙二醇为预处理溶剂,氯化铁为催化剂对棉秆进行预处理,实现了棉秆木质素和半纤维素的有效去除,提高了酶水解效率。以木质素和半纤维素的去除率为指标,运用正交试验方法优化乙二醇-氯化铁预处理条件。结果表明,棉秆在90%乙二醇水溶液,0.1 mol/L氯化铁,固液比1∶15,160 ℃条件下处理20 min,木质素和半纤维素去除率分别为85.7%和88.9%。相较原料,预处理后棉秆酶解率提高了7.6倍,葡萄糖产率达到100%（基质浓度5%,酶载量8.3 FPU/g,水解72 h条件下）。通过结构表征发现乙二醇-氯化铁预处理使棉秆的比表面积增大,致密结构被破坏,有效提高了棉秆的纤维素酶可及性。     

两步法预处理制备生物质燃料乙醇

为了扩展燃料乙醇制备的预处理工艺的发展方向,该文针对燃料乙醇制备的2种新预处理方法——半纤维素分离两步预处理法和木质素分离两步预处理法进行了试验研究。分别以能源植物柳枝稷和农业废弃物玉米秸秆为原料,考查了这2种方法对酶水解过程中糖产量的影响。结果表明,半纤维素分离两步预处理法对柳枝稷的较优处理条件为:第一步预处理用3%质量分数的过氧化氢溶液在50℃处理16h,第二步预处理用去离子水在121℃处理30min,最终酶水解可获得89%的纤维素转化率;木质素分离两步预处理法对玉米秸秆的较优处理条件为:第一步预处理用碱性乙醇溶液(1%质量分数氢氧化钠和70%质量分数乙醇)在80℃处理2h,第二步预处理为去离子水在135℃处理30min,最终酶水解可获得83%的纤维素转化率;扫描电镜观察,柳枝稷和玉米秸秆的纤维束均被破坏,纤维素酶的作用面积得到提高。同时,分离提取了部分半纤维素和木质素,可以回收提纯,应用于高附加值化学产品的制备。这一结果表明,这2种方法为实现燃料乙醇制备工程工业化提供依据。     

Hydrothermal Treatment of Date Palm Lignocellulose Residue for Organic Fertilizer Conversion: Effect on Cell Wall and Aerobic Degradation Rate

Date palm (Phoenix roebelenii) woodchips, a residue of palm tree plantations, was subjected to hydrothermal treatment (HTT) at mild reaction conditions (160°C < T < 220°C, 0.6 MPa < P < 2.4 MPa) for 30 min, and the effect of treatments on the cell wall (CW) solubilization and subsequent aerobic degradation rate (as CO production) was tested under controlled composting conditions during 63 days of incubation (38°C). The HTT at 160 and 180°C reaction temperatures notably solubilized hemicellulose, decreasing the fraction of this CW polymer from 34.1% in the untreated material, to 9.5 and 4.6% in the respective residues. However, treatment at 200 and 220°C reaction temperatures rapidly liquefied the lignin, which apparently went into solution with hemicellulose and appeared to stabilize a portion of this polysaccharides against hydrolysis. Consequently, the fraction of hemicellulose in 200 and 220°C – treated residues gradually increased; the respective values were 5.8 and 9.4%. The treatment temperature of 180°C was the most effective HTT temperature for subsequent aerobic degradation by solubilizing the largest portion of hemicellulose within the CW, which had two consequences: 1) it supplied additional readily bioavailable form of carbon, which in turn promoted rapid microbial activities in the early stage of decomposition; and 2) it created pores and cavities within the CW, which permitted rapid bacterial penetration and CW degradation. As a consequence, biodegradation of the residue treated under this reaction temperature proceeded rapidly and stability was reached within 21 days, compared to 63 days of continued degradation for the untreated CW. The enhanced biodegradability was also partially linked to the effect of 180°C treatment temperature on solubilization of amorphous cellulose and partial hydrolysis of lignin. Based on the results, the HTT system can successfully be used as a pretreatment step to accelerate the aerobic digestion rate of date palm residues for the production of organic fertilizers.