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建立了一种准确测定烟梗木质素含量的新方法。用低温NaOH/尿素水溶液抽提烟梗,采用优化的酸处理条件(硫酸浓度17.5 %、液固比80 mL?g-1、酸解温度100 ℃、酸解时间30 min)打断烟梗中木质素与纤维素等组份之间的化学键,残渣用低温NaOH/尿素水溶液进一步溶解纤维素、半纤维素等天然高分子物质,得到酸不溶木质素。酸溶木质素采用分光光度法在325 nm处测定,酸不溶木质素采用灼烧法测定。本方法RSD小于3%,准确度良好,且减少了有机溶剂预处理和浓硫酸处理,提高了测试的安全性。 相似文献
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The soil saprophytic fungus Myrothecium verrucaria was cultivated from glucose, starch, or xylan as the carbon source, and the biomass was compared with three selected feedstuffs. Fungal biomass was analyzed for nitrogen, protein, lipid, water soluble fraction, hemicellulose, cellulose, lignin, and residual ash, and the in vitro dry matter disappearance was determined. The chemical composition of M. verrucaria varied with substrate. In nitrogen content, the fungal biomass was more similar to alfalfa hay than to milo stalks or wheat straw. Content of water soluble fraction of fungal biomass was between those of alfalfa hay and milo stalks; content of hemicellulose was between those of milo stalks and wheat straw. The fungal fractions identified as cellulose and lignin varied widely with substrate. The fungal biomass was less digestible than alfalfa hay but more digestible than milo stalks or wheat straw. There may be potential uses of this organism in upgrading nutritive value of low-quality forages. 相似文献
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NDF, ADF, ‘cellulose’ and IVOMD residues, from feeding value determinations, were prepared from some forages, including straw, alkali-treated straw, grass and lucerne samples. The crude protein, cellulose, hemicellulose, uronic acid, Klason lignin, lignin and ash contents of these residues and the corresponding original forage samples were determined together with the relative composition of the neutral sugar constituents after acid hydrolysis. Cellulose, hemicellulose and Klason lignin were the main components in the NDF fractions but substantial amounts of crude protein (1–6%) also remained. Cellulose and Klason lignin were the main components in the ADF fractions, but 7–14% of the fractions was hemicellulose and 1–4% crude protein. Cellulose was the main component in the ‘cellulose’ fractions, but they also contained 8–13% hemicellulose, 2–7% Klason lignin and 2–11% ash. The composition of the IVOMD residues showed that cellulose and hemicellulose had been dissolved to about the same amounts (70–80%) and that most of the Klason lignin remained. 相似文献
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Evaluation of pretreatment with Pleurotus ostreatus for enzymatic hydrolysis of rice straw 总被引:5,自引:0,他引:5
Taniguchi M Suzuki H Watanabe D Sakai K Hoshino K Tanaka T 《Journal of Bioscience and Bioengineering》2005,100(6):637-643
The effects of biological pretreatment of rice straw using four white-rot fungi (Phanerochaete chrysosporium, Trametes versicolor, Ceriporiopsis subvermispora, and Pleurotus ostreatus) were evaluated on the basis of quantitative and structural changes in the components of the pretreated rice straw as well as susceptibility to enzymatic hydrolysis. Of these white-rot fungi, P. ostreatus selectively degraded the lignin fraction of rice straw rather than the holocellulose component. When rice straw (water content of 60%) was pretreated with P. ostreatus for 60 d, the total weight loss and the degree of Klason lignin degraded were 25% and 41%, respectively. After the pretreatment, the residual amounts of cellulose and hemicellulose were 83% and 52% of those in untreated rice straw, respectively. By enzymatic hydrolysis with a commercial cellulase preparation for 48 h, 52% holocellulose and 44% cellulose in the pretreated rice straw were solubilized. The net sugar yields based on the amounts of holocellulose and cellulose of untreated rice straw were 33% for total soluble sugar from holocellulose and 32% for glucose from cellulose. The SEM observations showed that the increase in susceptibility of rice straw to enzymatic hydrolysis by pretreatment with P. ostreatus is caused by partial degradation of the lignin seal. When the content of Klason lignin was less than 15% of the total weight of the pretreated straw, enhanced degrees of enzymatic solubilization of holocellulose and cellulose fractions were observed as the content of Klason lignin decreased. 相似文献
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CONCEPCIÓN VIDAL-VALVERDE JOSEFA HERRANZ INMACULADA BLANCO ENRIQUE ROJAS-HIDALGO 《Journal of food science》1982,47(6):1840-1845
The dietary fiber, cellulose, hemicellulose, lignin and pectic substances of 21 fruits have been determined. For some of these fruits several varieties and different degrees of ripeness have been considered. The contents of these compounds ranged between 0.2– 2.75% for dietary fiber, 0.06–1.8% for cellulose, 0.00–0.86% for hemicellulose, 0.06–0.5% for lignin and 0.12–1.28% for pectic substances. In some cases the dietary fiber can be affected by the fruit variety. Plantain increased in dietary fiber, hemicellulose and pectic substances content with increased ripening, while no change in cellulose and a decrease of lignin content were observed. 相似文献
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固态基质是固态发酵的核心,为了探究其异质性对固态发酵效率的影响,以不同部位玉米秸秆(鞘、茎、髓、叶)为固态基质,以硬毛粗盖孔菌(Funalia trogii)发酵生产漆酶,测定固态基质化学组成与物理性质,考察固态基质理化性质与漆酶产量关系,进一步从细胞壁角度探讨固态基质与微生物相互作用。结果表明,以髓为固态基质时,菌丝茂密且漆酶产量最高(110.70 U/g),鞘为固态基质时产量最低(26.40 U/g);髓具有最高的还原糖得率(239.44 mg/g)和较低的灰分含量,而鞘具有最低的还原糖得率(154.29 mg/g)和最高的半纤维素含量(36.65%);漆酶产量与木质素及还原糖得率呈显著正相关(P<0.05),与半纤维素及灰分呈显著负相关(P<0.05)。研究显示,固态基质异质性是影响固态发酵效率的重要因素。 相似文献
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The conversion of lignocellulosic biomass into biofuels or biochemicals typically involves a pretreatment process followed by the enzyme-catalyzed hydrolysis of cellulose and hemicellulose components to fermentable sugars. Many factors can contribute to the recalcitrance of biomass, e.g., the lignin content and structure, crystallinity of cellulose, degree of fiber polymerization, and hemicellulose content, among others. However, nonproductive binding between cellulase and lignin is the factor with the greatest impact on enzymatic hydrolysis. To reduce the nonproductive adsorption of enzymes on lignin and improve the efficiency of enzymatic hydrolysis, this review comprehensively summarized the progress that has been made in understanding the interactions between lignin and enzymes. Firstly, the effects of pretreatment techniques on lignin content and enzymatic hydrolysis were reviewed. The effects of lignin content and functional groups on enzymatic hydrolysis were then summarized. Methods for the preparation and characterization of lignin films were assessed. Finally, the methods applied to characterize the interactions between lignin and cellulase were reviewed, and methods for decreasing the nonproductive binding of enzymes to lignin were discussed. This review provides an overview of the current understanding of how lignin hinders the enzymatic hydrolysis of lignocellulosic biomass, and provides a theoretical basis for the development of more economical and effective methods and additives to reduce the interaction of lignin and enzymes to improve the efficiency of enzymatic hydrolysis. 相似文献
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JOSEFA HERRANZ CONCEPCION VIDAL-VALVERDE ENRIQUE ROJAS-HIDALGO 《Journal of food science》1981,46(6):1927-1933
The content in NDF, ADF, cellulose, hemicellulose, and lignin of 22 raw and 19 cooked vegetables (14 boiled, and 5 fried) widely consumed among the Spanish population was determined according to the method of Van Soest. Cooking generally increases the NDF, ADF and cellulose content on a dry weight basis. Normal size servings of the vegetables were prepared and their NDF, cellulose, hemicellulose and lignin contents calculated. We observed that, with vegetables of common use, a total amount of 15–20 g/day of these fiber components can be obtained; according to current knowledge this implies beneficial physiological effects for a broad human pathology. 相似文献
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JOSEFA HERRANZ CONCEPCION VIDAL-VALVERDE ENRIQUE ROJAS-HIDALGO 《Journal of food science》1983,48(1):274-275
The NDF, ADF, cellulose, hemicellulose and lignin contents of five frozen vegetables (raw and boiled) and five canned vegetables (two of them fried) have been studied. In general, it was observed that boiling resulted in an increase in the NDF, ADF and cellulose content. There was also a slight increase in hemicellulose values. The lignin contents of most vegetables did not change upon boiling. When the cooking process was frying, a drastic decrease of NDF, ADF, cellulose, and lignin contents occurred, while the amount of hemicellulose changed slightly in the vegetables analyzed. 相似文献
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《Journal of dairy science》2021,104(11):11660-11672
Pleurotus ostreatus (oyster mushroom) synthesizes enzymes that degrade lignin, cellulose, and hemicellulose. The objectives of this study were to evaluate the effect of Pleurotus ostreatus spent substrate (POSS) on whole-plant corn silage (WPCS) chemical composition, antioxidant capacity, lignin monomers, and in vitro digestibility, as well as the performance of lactating goats fed corn silage treated with different levels of POSS. In experiment 1, 4 levels of lignocellulolytic enzymes were tested in a complete randomized design: 0, 10, 20, and 30 mg of lignocellulosic enzymes per kilogram of fresh matter, 4 replicates per treatment (vacuum-sealed bags). The bags were opened 60 d after ensiling. In experiment 2, corn silage treated with 3 enzyme levels (0, 10, or 30 mg/kg of fresh matter) was fed to lactating goats as part of the total mixed ration. Nine lactating Saanen goats (62.68 ± 7.62 kg BW; 44 ± 8 d in milk; 2.91 ± 0.81 kg of milk/day, mean ± SD) were assigned to three 3 × 3 Latin squares. Data were analyzed using the GLIMMIX procedure of SAS (version 9.4, SAS Institute Inc.), and means were compared by linear and quadratic orthogonal contrast. In experiment 1, neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin, and cellulose quadratically decreased in the WPCS treated with POSS. At the nadir point, POSS decreased NDF by 14.1%, ADF by 19.5%, lignin by 9.07%, and cellulose by 22.1% compared with the untreated silage. Therefore, POSS led to a quadratic increase in in vitro dry matter digestibility of WPCS (+8.88% at the vertex) compared with the untreated silage. In experiment 2, POSS quadratically increased the in vivo total-tract ADF digestibility. Also, the concentration of polyphenols in the milk of goats linearly increased with the addition of POSS, and no differences were observed among treatments for milk yield and composition. In summary, adding 10 mg of lignocellulolytic enzymes from POSS per kilogram of fresh matter of whole-plant corn at ensiling had a more evident reduction in lignin and cellulose concentration, leading to greater in vitro digestibility, as well as greater in vivo ADF digestibility; however, milk yield was not different among treatments. 相似文献
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In the current research, kenaf represents an agricultural biomass that possesses enormous potential for industrial applications. Because of its complex structure, which is composed of cellulose, hemicellulose, and lignin, pretreatment process was conducted. Here, dilute acid pretreatment process was conducted, statistically using the response surface method, which included three parameters: mass of biomass (g), temperature (°C), and time (min). About 2 g of kenaf biomass was treated with 2% dilute sulphuric acid, and it was found to have higher glucose conversion (25.3%) when the process was conducted for 60 min at the temperature of 180°C. The main aim of the current research is to investigate the chemical and physical changes of kenaf biomass before and after the pretreatment. The changes could be clearly seen in the cellulose, hemicellulose, and lignin composition before and after the pretreatment, which were evaluated via TAPPI standard test methods. Morphological observation under scanning electron microscope confirmed the changes that took place on the kenaf biomass from complex to simple surface structure. Fourier transform infrared analysis confirmed the presence of cellulose, hemicellulose, and lignin contents of the kenaf biomass before and after pretreatment. Crystallinity of the treated kenaf biomass also increased from 46.6% to 70.0%, as evidenced from X-ray diffractometer analysis. 相似文献
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Non-thermal plasma as an innovative pretreatment technology in delignification of brewery by-product
Non-thermal plasma was applied as an innovative pretreatment for the delignification of brewery by-products. The influence of different plasma gases (pure air or air/argon), time and solids concentration (7.5, 10 and 12.5%) was evaluated during the delignification tests. The levels of cellulose, hemicellulose and lignin were monitored before and after treatment. The reduction in lignin content was approximately 50% after 5 min using pure air in all tested solids concentrations. Longer pretreatment times (60 min) influenced the removal of hemicellulose (50%) and cellulose (12%), also indicated by morphological changes. After 5 and 60 min of plasma application, the physical-chemical characteristics showed minor changes in its chemical composition, mainly affected by the losses of lignocellulosic compounds. Non-thermal plasma is considered an attractive alternative for the pretreatment of brewery by-products, resulting mainly in removing lignin, assisting in subsequent processes such as the enzymatic hydrolysis of the spent solid. 相似文献
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I. S. Bhatia Rangil Singh K. K. Dogra Saroj Dua 《Journal of the science of food and agriculture》1975,26(9):1391-1398
Changes in the cell-wall carbohydrates and lignin of bajra (Pennisetum typhoides), jowar (Sorghum vulgare) and napier (Pennisetum purpureum)–bajra hybrids (NB21) as affected by growth stage are reported. With growth of the plants the concentrations of α-cellulose and hemicellulose increased in the stems. In bajra and jowar this increase was gradual up to 60–70 days growth stage followed by a decline and a subsequent rise towards maturity. In contrast, in NB21, α-cellulose continued to rise gradually throughout the growth period. The concentration of hemicellulose was much higher in the stems than in the leaves of NB21. With the ageing of the plants the lignin content increased in all these forage crops. In NB21 the stems contained more lignin than the leaves at all stages of maturity. Fluctuations in the contents of lignin, cellulose and hemicellulose followed similar trends indicating that possibly they are components of a common matrix in the cell wall. In NB21 the water-soluble carbohydrates continued to rise throughout the growth period unlike other forage crops. The protein content decreased as the NB21 plants matured. The protein content of the leaves of these plants was always higher than that of the stems. The oxalates gradually declined with the maturation of the plants. 相似文献
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分别采用稀酸和酸碱顺序两种方法处理稻草秸秆,20 FPU/g(底物干重)的纤维素酶、底物质量浓度为80 g/L,45℃酶解72 h。结果表明,木质素与半纤维素对纤维素转化为葡萄糖都有较大影响,稀酸处理的秸秆酶解纤维素转化率(43.4%,葡萄糖质量浓度24.1 g/L)是未处理秸秆(16.8%,葡萄糖质量浓度6.2 g/L)的2.6倍,而酸碱顺序处理的秸秆(60.6%,葡萄糖质量浓度47.7 g/L)则是未处理秸秆的3.6倍。采用上述两种方法处理秸秆后,秸秆木质素和半纤维素被移去,秸秆结构发生改变,从而秸秆纤维更易受纤维素酶的攻击,并且秸秆木质素和半纤维素质量分数越低,纤维素的酶解得率就越高。 相似文献