期刊文献+
共找到45篇文章
< 1 2 3 >
每页显示 20 50 100
Optimizing hemicelluloses pre-extraction in eucalyptus kraft pulping:A pathway towards enhancing pulp mill biorefineries
1
作者 Yuhan Wang Danqi Xue +1 位作者 Jingjing Zhuo Zhouyang Xiang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第6期162-172,共11页
A critical pathway towards enhancing pulp mill biorefineries is to integrate the extraction and utilization of hemicelluloses into the pulping processes.Hence,an industrial pre-extraction strategy for hemicelluloses t... A critical pathway towards enhancing pulp mill biorefineries is to integrate the extraction and utilization of hemicelluloses into the pulping processes.Hence,an industrial pre-extraction strategy for hemicelluloses targeting eucalyptus kraft pulping process was developed.Alkaline solution or pulping white liquor was used to pre-extract hemicelluloses before the actual pulping process.The response surface methodology(RSM)technique was applied to investigate the most suitable conditions to maximize the yield of these hemicelluloses while simultaneously minimizing the damage to pulp yields and properties.Temperature(105 to 155℃),alkali concentration(3%to 8%),sulfidity(20%to 30%)and retention time(19 to 221 min)were combined to evaluate their effects on hemicellulose yields and chemical structures.The optimal pre-extraction conditions identified in this work(5.75%NaOH concentration,25%sulfidity at 135℃for 60 min)successfully allowed recovering 4.8%of hemicelluloses(based on the wood dry mass)and limited damages to pulp yields and properties.The cellulose content in pulp can even be increased by about 10%.Hemicellulose emulsification properties were also evaluated,which were comparable to synthetic emulsifiers.This study provides an industrial pathway to effectively separate and utilize wood hemicelluloses from the pulping process,which has the potential to improve the economy and material utilization of pulp and paper mills. 展开更多
关键词 Hemicelluloses XYLAN Pre-extraction Kraft pulping EMULSIFYING Response surface methodology(RSM)
下载PDF
The DUF579 proteins GhIRX15s regulate cotton fiber development by interacting with proteins involved in xylan synthesis
2
作者 Mengyun Li Feng Chen +6 位作者 Jingwen Luo Yanan Gao Jinglong Cai Wei Zeng Monika S.Doblin Gengqing Huang Wenliang Xu 《The Crop Journal》 SCIE CSCD 2024年第4期1112-1125,共14页
Cotton provides the most abundant natural fiber for the textile industry.The mature cotton fiber largely consists of secondary cell walls with the highest proportion of cellulose and a small amount of hemicellulose an... Cotton provides the most abundant natural fiber for the textile industry.The mature cotton fiber largely consists of secondary cell walls with the highest proportion of cellulose and a small amount of hemicellulose and lignin.To dissect the roles of hemicellulosic polysaccharides during fiber development,four IRREGULAR XYLEM 15(IRX15)genes,GhIRX15-1/-2/-3/-4,were functionally characterized in cotton.These genes encode DUF579 domain-containing proteins,which are homologs of AtIRX15 involved in xylan biosynthesis.The four GhIRX15 genes were predominantly expressed during fiber secondary wall thickening,and the encoded proteins were localized to the Golgi apparatus.Each GhIRX15 gene could restore the xylan deficient phenotype in the Arabidopsis irx15irx15l double mutant.Silencing of GhIRX15s in cotton resulted in shorter mature fibers with a thinner cell wall and reduced cellulose content as compared to the wild type.Intriguingly,GhIRX15-2 and GhIRX15-4 formed homodimers and heterodimers.In addition,the GhIRX15s showed physical interaction with glycosyltransferases GhGT43C,GhGT47A and GhGT47B,which are responsible for synthesis of the xylan backbone and reducing end sequence.Moreover,the GhIRX15s can form heterocomplexes with enzymes involved in xylan modification and side chain synthesis,such as GhGUX1/2,GhGXM1/2 and GhTBL1.These findings suggest that GhIRX15s participate in fiber xylan biosynthesis and modulate fiber development via forming large multiprotein complexes. 展开更多
关键词 Cotton fiber Xylan biosynthesis GhIRX15s Protein-protein interaction Protein complexes
下载PDF
Study on the green extraction of corncob xylan by deep eutectic solvent
3
作者 Bingyu Jiao Le Wang +3 位作者 Haitao Gui Zifu Ni Rong Du Yuansen Hu 《Grain & Oil Science and Technology》 CAS 2024年第1期50-59,共10页
Corn as one of the world's major food crops,its by-product corn cob is also rich in resources.However,the unreasonable utilization of corn cob often causes the environmental pollution,waste of resources and other ... Corn as one of the world's major food crops,its by-product corn cob is also rich in resources.However,the unreasonable utilization of corn cob often causes the environmental pollution,waste of resources and other problems.As one of the most abundant polymers in nature,xylan is widely used in food,medicine,materials and other fields.Corn cob is rich in xylan,which is an ideal raw material for extracting xylan.However,the intractable lignin is covalently linked to xylan,which increases the difficulty of xylan extraction.It has been reported that the deep eutectic solvent(DES)could preferentially dissolve lignin in biomass,thereby dissolving the xylan.Then,the xylan in the extract was separated by ethanol precipitation method.The xylan precipitate was obtained after centrifugation,while the supernatant was retained.The components of the supernatant after ethanol precipitation were separated by the rotary evaporator.The ethanol,water and DES were collected for the subsequent extraction of corn cob xylan.In this study,a novel way was provided for the green production of corn cob xylan.The DES was used to extract xylan from corn cob which was used as the raw material.The effects of solid-liquid ratio,reaction time,reaction temperature and water content of DES on the extraction rate of corn cob xylan were investigated by the single factor test.Furthermore,the orthogonal test was designed to optimize the xylan extraction process.The structure of corn cob xylan was analyzed and verified.The results showed that the optimum extraction conditions of corn cob xylan were as follows:the ratio of corn cob to DES was 1:15(g:mL),the extraction time was 3 h,the extraction temperature was 60℃,and the water content of DES was 70%.Under these conditions,the extraction rate of xylan was 16.46%.The extracted corn cob xylan was distinctive triple helix of polysaccharide,which was similar to the structure of commercially available xylan.Xylan was effectively and workably extracted from corn cob by the DES method.This study provided a new approach for high value conversion of corn cob and the clean production of xylan. 展开更多
关键词 CORNCOB Deep eutectic solvent XYLAN Process optimization EXTRACTION
下载PDF
Stimbiotic supplementation modulated intestinal inflammatory response and improved broilers performance in an experimentally-induced necrotic enteritis infection model
4
作者 Ji Hwan Lee Byongkon Lee +9 位作者 Xavière Rousseau Gilson A.Gomes Han Jin Oh Yong Ju Kim Se Yeon Chang Jae Woo An Young Bin Go Dong Cheol Song Hyun Ah Cho Jin Ho Cho 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2023年第1期322-338,共17页
Background:Two experiments were conducted to establish an optimal NE challenge model and evaluate the efficacy of stimbiotic(STB)supplementation in necrotic enteritis(NE)challenged broilers.In Exp.1,a total of 120 Arb... Background:Two experiments were conducted to establish an optimal NE challenge model and evaluate the efficacy of stimbiotic(STB)supplementation in necrotic enteritis(NE)challenged broilers.In Exp.1,a total of 120 Arbor Acres(AA)broilers(45.0±0.21 g)were randomly assigned to 6 treatments in a 3×2 factorial arrangement.Vaccine treatments included non-challenge(0),×10 the recommended dose(×10)or×20 the recommended dose(×20)by the manufacturer.Clostridium perfringens(CP)treatments were non-challenge(No)or 3 mL of 2.2×10^(7)CFU CP challenge(Yes).In Exp.2,a total of 72 AA broilers(40.17±0.27 g)were randomly assigned to 6 treatments in a 3×2 factorial arrangement.Dietary treatments included non-additive(CON),100 mg/kg STB(STB)and 100 mg/kg STB on top of a typical commercial blend including an essential oil,probiotics,and enzyme(CB).Challenge treatments included non-NE challenge(No)and NE challenge(Yes)as established in Exp.1.Results:In Exp.1,CP and vaccine challenge decreased(P<0.05)body weight(BW),body weight gain(BWG)and feed intake(FI),and increased(P<0.05)the number of broilers with diarrhea and intestinal lesions.The oral administration of×20 recommended dose of vaccines coupled with 3 mL of 2.2×10^(7)CFU CP resulted in(P<0.01)a significantly increased incidence of wet litter and intestinal lesions.Thus,this treatment was chosen as the challenge model for the successful inducement of NE in Exp.2.In Exp.2,the NE challenge negatively affected(P<0.01)growth performance,ileal morphology,immunoglobulin contents in blood,caecal microbiota in the caecum,footpad dermatitis,intestinal lesion scores,tumour necrosis factor(TNF-α)and endotoxin in the serum compared with the non-NE challenged birds.The supplementation of STB and CB in diets enhanced(P<0.05)growth performance,intestinal microbiota,and blood profiles by stimulating ileal morphology(VH and VH:CD)and propionate production in the cecum,and there were no differences in measured variables between STB and CB supplemented birds.Conclusion:Overall,these results indicate that STB supplementation was able to reduce the inflammatory response and improve the performance of NE challenged birds,and the supplementation of STB alone was as effective as a typical commercial blend containing a number of other additives. 展开更多
关键词 Broiler chicken Clostridium perfringens Necrotic enteritis xylanse XYLOOLIGOSACCHARIDE
下载PDF
卷须链霉菌木聚糖酶水解玉米芯汽爆液及酵母发酵精制低聚木糖 被引量:13
5
作者 张艳艳 薛文通 +2 位作者 江正强 李里特 丁长河 《食品与发酵工业》 CAS CSCD 北大核心 2004年第4期12-16,共5页
研究了卷须链霉菌 (Streptomycescirratus)D 1 0木聚糖酶水解玉米芯汽爆液的酶用量和水解时间 ,结果得到 80U/ 1 0 0mL酶用量和水解 6h是合适的加酶量和水解时间 ;筛选出 1株能够精制低聚木糖的Candiasp .酵母 ,该酵母能消耗木糖、阿拉... 研究了卷须链霉菌 (Streptomycescirratus)D 1 0木聚糖酶水解玉米芯汽爆液的酶用量和水解时间 ,结果得到 80U/ 1 0 0mL酶用量和水解 6h是合适的加酶量和水解时间 ;筛选出 1株能够精制低聚木糖的Candiasp .酵母 ,该酵母能消耗木糖、阿拉伯糖而不消耗木二糖 ;利用此酵母精制酶解液 ,在接菌量为 1 0 %,48h时酶解液中木糖、阿拉伯糖完全被消耗 ,木二糖以上的低聚木糖含量变化不明显 。 展开更多
关键词 卷须链霉菌 木聚糖酶 水解 玉米芯汽爆液 酵母发酵 精制 低聚木糖 酶用量
下载PDF
木聚糖酶的特性及应用研究 被引量:14
6
作者 万红贵 王涛 +2 位作者 蔡恒 贾伟 郑伟刚 《食品与发酵工业》 CAS CSCD 北大核心 2008年第3期92-95,共4页
木聚糖酶(Xylanase)[EC 3.2.1.8]是指将木聚糖降解成低聚糖和木糖的一组酶的总称,是木聚糖降解酶系中最关键的酶。文中对木聚糖酶的特性,测定酶活的方法,以及木聚糖酶在工业上的应用进行综述。
关键词 木聚糖酶 特性 检测 应用
下载PDF
8种食用菌菌渣中3种饲用酶活性的测定 被引量:29
7
作者 张国庆 董晓芳 +2 位作者 王贺祥 佟建明 张琪 《中国食用菌》 北大核心 2009年第5期28-29,56,共3页
对可商业化人工栽培的8种常见食用菌菌渣中的木聚糖酶、β-葡聚糖酶和植酸酶生物活性进行了测定。结果表明,被测的8个样品均不同程度具有木聚糖酶和β-葡聚糖酶活性。其中,双孢蘑菇和毛木耳菌渣木聚糖酶活性最高,分别为2.856U·g-1... 对可商业化人工栽培的8种常见食用菌菌渣中的木聚糖酶、β-葡聚糖酶和植酸酶生物活性进行了测定。结果表明,被测的8个样品均不同程度具有木聚糖酶和β-葡聚糖酶活性。其中,双孢蘑菇和毛木耳菌渣木聚糖酶活性最高,分别为2.856U·g-1和1.109U·g-1;杏鲍菇和毛木耳菌渣β-葡聚糖酶活性最高,分别为0.389U·g-1和0.351U·g-1;毛木耳在pH2.5和pH5.2下均具有植酸酶活性,分别为0.139U·g-1和0.222U·g-1;杏鲍菇和糙皮侧耳在pH5.2下,植酸酶活性分别为0.126U·g-1和0.122U·g-1;其它菌渣均不具有明显的植酸酶活性。本研究表明,食用菌菌渣中具有一定的饲用酶活性,利用食用菌菌渣作为畜禽饲料,可在一定程度上减少饲用酶的添加,从而降低生产成本。 展开更多
关键词 食用菌菌渣 木聚糖酶 Β-葡聚糖酶 植酸酶 活性
下载PDF
木聚糖酶酶活性测定方法及酶活性单位定义 被引量:21
8
作者 王晓丹 郭丽琼 +1 位作者 赵力超 林俊芳 《食品与发酵工业》 CAS CSCD 北大核心 2009年第9期128-131,共4页
为统一木聚糖酶酶活性的单位定义及测定方法进行了实验。通过对现有酶活性的单位定义及测定方法的比较分析,得出木聚糖酶的酶活性单位定义为:在特定条件下,每分钟水解木聚糖形成1μmol木糖(还原糖)所需酶量为1个酶活力单位(U),并且采用... 为统一木聚糖酶酶活性的单位定义及测定方法进行了实验。通过对现有酶活性的单位定义及测定方法的比较分析,得出木聚糖酶的酶活性单位定义为:在特定条件下,每分钟水解木聚糖形成1μmol木糖(还原糖)所需酶量为1个酶活力单位(U),并且采用还原糖法中的DNS法作为测定木聚糖酶酶活性的方法,该法具有合理性和科学性,建议以此作为木聚糖酶酶活性测定及酶活性单位定义的统一方法。 展开更多
关键词 木聚糖酶 酶活性测定 酶活性单位定义
下载PDF
不同酶制剂对降低大麦、小麦和黑麦粘性的作用 被引量:4
9
作者 徐子伟 邓波 +3 位作者 刘敏华 费笛波 李永明 徐莹 《浙江农业学报》 CSCD 2004年第1期21-24,共4页
用不同酶谱、不同剂量的酶制剂对大麦、小麦和黑麦抽提液进行降解粘度的调控试验,通过数学分析得出,对大麦降粘度,β 葡聚糖酶起主导作用,木聚糖酶作用较小;对黑麦和小麦降粘度,以木聚糖酶作用为主。
关键词 Β-葡聚糖酶 木聚糖酶 粘度 大麦 小麦 黑麦
下载PDF
卷须链霉菌D-10木聚糖酶酶解玉米芯汽爆液制备低聚木糖的研究 被引量:3
10
作者 薛文通 张艳艳 +1 位作者 范俊峰 江正强 《食品科学》 EI CAS CSCD 北大核心 2004年第z1期138-144,共7页
本文研究了卷须链霉菌(StreptomycescirratusD-10)木聚糖酶水解玉米芯汽爆液,碱提玉米芯木聚糖的合适酶用量和酶水解时间,分别为80U/100mL,6h和60u/g,8h。同时以玉米芯粉作为酶解对照。表明玉米芯不同处理底物,汽爆液水解率最高,碱提玉... 本文研究了卷须链霉菌(StreptomycescirratusD-10)木聚糖酶水解玉米芯汽爆液,碱提玉米芯木聚糖的合适酶用量和酶水解时间,分别为80U/100mL,6h和60u/g,8h。同时以玉米芯粉作为酶解对照。表明玉米芯不同处理底物,汽爆液水解率最高,碱提玉米芯木聚糖水解率次之。酶解产物经TLC分析表明卷须链霉菌D-10酶解产物以木二糖和木三糖为主,产物中没有阿拉伯糖,玉米芯汽爆液酶解产物中含有微量的阿拉伯糖。 展开更多
关键词 卷须链霉菌D-10 木聚糖酶 酶水解特性
下载PDF
重组木聚糖酶的安全高效表达与应用研究 被引量:5
11
作者 暴立娟 宋庆凤 李杰 《食品工业科技》 CAS CSCD 北大核心 2011年第1期156-158,161,共4页
以pPIC9为载体能够实现里氏木霉木聚糖酶基因(xyn2)在巴斯德毕赤酵母(Pichia pastoris)中的高效表达,但是却需要甲醇诱导,从而限制其在食品加工等领域的应用。本研究以毕赤酵母组成型启动子——GAP启动子替换pPIC9上的甲醇诱导型启动子A... 以pPIC9为载体能够实现里氏木霉木聚糖酶基因(xyn2)在巴斯德毕赤酵母(Pichia pastoris)中的高效表达,但是却需要甲醇诱导,从而限制其在食品加工等领域的应用。本研究以毕赤酵母组成型启动子——GAP启动子替换pPIC9上的甲醇诱导型启动子AOX,成功地表达了木聚糖酶。在此基础上以经密码子优化后的INU信号肽替换载体上原有的α-Factor信号肽,同时根据已发表的基因序列和AOX1基因的氨基酸序列,按照毕赤酵母的酵母偏爱密码子,对毕赤酵母表达载体pPIC9上的α信号肽序列进行改造,结果表明,两种信号肽均能够引导木聚糖酶的分泌。通过添加0.01%的Triton,可以有效增强细胞膜的通透性,提高外源蛋白的分泌能力。薄层层析结果表明,木聚糖酶的酶解产物为木二糖和木三糖为主的低聚木糖及少量的木糖。 展开更多
关键词 木聚糖酶 GAP启动子 INU信号肽 α信号肽 低聚木糖
下载PDF
两种漆酶/木聚糖酶体系降解木质素能力的比较 被引量:3
12
作者 尤纪雪 王玉秀 +1 位作者 童国林 欧阳嘉 《中国造纸》 CAS 北大核心 2009年第3期1-5,共5页
通过白腐菌合成的(LXS)与复配的(L+X)漆酶/木聚糖酶体系降解木质素能力的比较表明,LXS具有较强的降解木质素能力。在酶用量10 IU/g时,与L+X相比,LXS酶处理浆的卡伯值低1.1个单位;酶处理液吸光度高20.6%。4种酶(体系)处理结果的比较表明,... 通过白腐菌合成的(LXS)与复配的(L+X)漆酶/木聚糖酶体系降解木质素能力的比较表明,LXS具有较强的降解木质素能力。在酶用量10 IU/g时,与L+X相比,LXS酶处理浆的卡伯值低1.1个单位;酶处理液吸光度高20.6%。4种酶(体系)处理结果的比较表明,L+X降解木质素的能力比LXS差,也无法与漆酶/介体体系(LMS)相比。对马尾松浆和桉木浆处理结果的分析,证明了LXS具有与LMS相同的较强降解木质素的能力。用不同酶活比的LXS处理浆料时,发现漆酶与木聚糖酶酶活比越小,酶处理液的吸光度越大,酶处理浆的卡伯值越低,脱木素能力越强。对酶处理后浆料强度和结晶度测定,证明LXS、LMS和L+X对纤维没有任何损伤。 展开更多
关键词 漆酶/木聚糖酶体系 漆酶/介体体系 木质素
下载PDF
木聚糖酶处理尾巨桉KP-AQ浆工艺条件的研究 被引量:1
13
作者 姚春丽 谈滔 张莹 《北京林业大学学报》 CAS CSCD 北大核心 2009年第S1期156-160,共5页
该文首次将Thermomyces lanuginosus产商业用木聚糖酶用于漂白阔叶木尾巨桉硫酸盐浆,摸索出其较佳的漂白工艺条件:酶用量10 U/g,反应时间90 min,处理温度60℃,pH值6.0,浆浓度10%。在该条件下,生物预处理纸浆的白度为55.2%,比氧处理后的... 该文首次将Thermomyces lanuginosus产商业用木聚糖酶用于漂白阔叶木尾巨桉硫酸盐浆,摸索出其较佳的漂白工艺条件:酶用量10 U/g,反应时间90 min,处理温度60℃,pH值6.0,浆浓度10%。在该条件下,生物预处理纸浆的白度为55.2%,比氧处理后的浆上升了3.7%,卡伯值下降为8.38;纸浆黏度为990 mL/g,比氧处理后的浆有所提高。与未经处理的对照浆相比,纸浆经过木聚糖酶预处理再接不同后续漂白,纸浆卡伯值下降,白度有所上升。 展开更多
关键词 尾巨桉 木聚糖酶 白度 卡伯值 黏度
下载PDF
Row Spacing Affects Biomass Yield and Composition of Kenaf (<i>Hibiscus cannabinus</i>L.) as a Lignocellulosic Feedstock for Bioenergy 被引量:2
14
作者 Marisol T. Berti Srinivas Reddy Kamireddy Yun Ji 《Journal of Sustainable Bioenergy Systems》 2013年第1期68-73,共6页
Kenaf (Hibiscus cannabinus L.) is a warm-season annual. Kenaf fibers are commonly used for paper pulp and cordage, but it is also a promising lignocellulosic feedstock for bioenergy production, although optimum plant ... Kenaf (Hibiscus cannabinus L.) is a warm-season annual. Kenaf fibers are commonly used for paper pulp and cordage, but it is also a promising lignocellulosic feedstock for bioenergy production, although optimum plant density for biomass production has not been determined for the northern region of the USA. The objective of this study was to determine the best plant density and row spacing of kenaf to maximize biomass yield and chemical composition for biofuel conversion. The experiments were conducted at Fargo and Prosper, ND, in 2010 and 2011. The experiment was a randomized complete block design with a split-plot arrangement where the main plot was tworowspacings (30 and60 cm) and the sub-plot fourplant densities (32, 16, 8, and 4 plants·m-2). Row spacing had a significant effect on both biomass and biofuel yield. Narrower rows had higher biomass and biofuel yield. Maximum biomass and estimated biofuel yield was obtained with the two highest plant densities of 16 and 32 plants·m-2 and fluctuated between 9.45 and 10.22 Mg·ha-1 and 1354 and1464 L·ha-1, respectively. Stem diameter increased with a decrease in plant density. Chemical composition varied with plant density;glucan (27%) and xylan (9.8%) content were lower at the lowest plant density. Ash content was not different among plant densities but it is interesting to mention the very low ash content of kenaf (0.15%). According to the results of this study, it is recommended to plant kenaf at 30-cm rows with a plant density of 16 to 32 plants·m-2 to maximize biomass yield. Kenaf has a tremendous potential as a cellulosic feedstock for biofuel and green chemicals in the Northern Great Plains because of high biomass yield and low ash content. 展开更多
关键词 BIOENERGY LIGNOCELLULOSIC FEEDSTOCK Plant Density GLUCANS xylans Ash
下载PDF
重组极耐热木聚糖酶和重组极耐热漆酶协同漂白麦草浆
15
作者 郑志强 李华钟 邵蔚蓝 《工业微生物》 CAS CSCD 2014年第3期1-6,共6页
利用来自海栖热袍茵的重组极耐热木聚糖酶XynB和来自嗜热栖热菌Thermus thermophilus HB27的重组极耐热漆酶Tth-laccase对麦草浆进行协同漂白。结果表明,当未漂浆经XL漂序处理(X:重组木聚糖酶用量20 U/g绝干浆,pH 5.8,温度90℃,浆浓8%,... 利用来自海栖热袍茵的重组极耐热木聚糖酶XynB和来自嗜热栖热菌Thermus thermophilus HB27的重组极耐热漆酶Tth-laccase对麦草浆进行协同漂白。结果表明,当未漂浆经XL漂序处理(X:重组木聚糖酶用量20 U/g绝干浆,pH 5.8,温度90℃,浆浓8%,处理时间2 h;L:重组漆酶用量3 U/g绝干浆,pH 4.5,温度90℃,浆浓8%,处理时间1.5 h),可获得最佳漂白效果。与对照浆比较,XL处理使浆料白度提升11.5%ISO,卡伯值降低6.9。双酶协同处理在改善浆料可漂性的同时,对纸浆纤维强度无负面影响。在后续过氧化氢漂白段中,当漂终白度相近时,XL预处理浆可节省约50%H_2O_2消耗量。 展开更多
关键词 木聚糖酶 漆酶 麦草浆 漂白 海栖热袍菌 嗜热栖热菌
下载PDF
蛋白质序列的聚类结构分析 被引量:4
16
作者 陶华 唐旭清 《生物信息学》 2012年第4期269-273,279,共6页
基于模糊邻近关系的粒度空间,对蛋白质序列进行聚类结构分析。利用MEGA软件计算选取的木聚糖酶序列间的比对距离,引入内积将其转化为模糊邻近关系(或矩阵),再应用算法求解其粒度空间,进行序列的聚类结构分析和最佳聚类确定研究。这些研... 基于模糊邻近关系的粒度空间,对蛋白质序列进行聚类结构分析。利用MEGA软件计算选取的木聚糖酶序列间的比对距离,引入内积将其转化为模糊邻近关系(或矩阵),再应用算法求解其粒度空间,进行序列的聚类结构分析和最佳聚类确定研究。这些研究为蛋白质序列提供了定量分析的工具。 展开更多
关键词 蛋白质序列 模糊邻近关系 粒度空间 最佳聚类 木聚糖酶
下载PDF
杏鲍菇菌糠制备富含低聚木糖饲料工艺的研究 被引量:2
17
作者 梅桥 黄元昊 +4 位作者 彭英杰 张俊豪 舒志恒 黄莉 兰时乐 《饲料研究》 CAS 北大核心 2022年第15期62-66,共5页
试验旨在研究使用杏鲍菇菌糠制备低聚木糖饲料的工艺。试验以杏鲍菇菌糠为原料,低聚木糖产量为指标,采用单因素试验法研究杏鲍菇菌糠预处理条件及酶解条件对低聚木糖产量的影响,并对低聚木糖产量影响较大的因素通过正交试验法进行优化... 试验旨在研究使用杏鲍菇菌糠制备低聚木糖饲料的工艺。试验以杏鲍菇菌糠为原料,低聚木糖产量为指标,采用单因素试验法研究杏鲍菇菌糠预处理条件及酶解条件对低聚木糖产量的影响,并对低聚木糖产量影响较大的因素通过正交试验法进行优化。结果显示:适宜的预处理工艺为:预处理温度50℃、H_(2)O_(2)3%、Na_(2)CO_(3)4%、液料比2.5 mL/g、预处理时间3 h。适宜的酶解工艺为:木聚糖酶400 U/g、纤维素酶400 U/g、甘露聚糖酶400 U/g、液料比4 mL/g、酶解温度50℃、酶解初始pH值6.0、酶解时间4 h。此条件下,酶解物料中低聚木糖产量达97.67 mg/g。研究表明,该工艺为杏鲍菇菌糠的高效利用提供了新思路。 展开更多
关键词 杏鲍菇菌糠 低聚木糖 木聚糖酶 纤维素酶 甘露聚糖酶
下载PDF
Effects of Different Pretreatment Modes on the Enzymatic Digestibility of Corn Leaf and Corn Stalk 被引量:8
18
作者 苏东海 孙君社 +1 位作者 刘萍 吕燕萍 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2006年第6期796-801,共6页
Corn leaf and corn stalk were pretreated with only hot water and 0.1% sulfuric acid at 160℃ or 200℃, respectively. For hot water pretreatment, the pH of corn stalk hydrolysate decreased more rapidly than that of cor... Corn leaf and corn stalk were pretreated with only hot water and 0.1% sulfuric acid at 160℃ or 200℃, respectively. For hot water pretreatment, the pH of corn stalk hydrolysate decreased more rapidly than that of corn leaf as the reaction time increased. On the contrary, the pH of corn leaf hydrolysate increased more than that of corn stalk with diluted acid addition. Increasing temperature enhanced the xylose dissolution rate and increased cellulose digestibility. Compared with hot water, 0.1% sulfuric acid addition improved the xylan removal and the enzymatic hydrolysis of both corn leaf and corn stalk residue. Much less xylan must be removed to achieve the same cellulose digestibility for the corn leaf as that for the corn stalk; 55% digestibility was obtained when only 32% xylan was removed from corn leaf, whereas corn stalk required removal of about 50% of the xylan to achieve the same di- gestibility. Overall, the descending order of enzymatic digestibility was: dilute acid hydrolysate of corn leaf > dilute acid hydrolysate of corn stalk > water-only hydrolysate of corn leaf > water-only hydrolysate of corn stalk. Finally, one separate pretreatment strategy was developed to transfer corn leaf and corn stalk to fermentable sugars for fur- ther bioenergy production. 展开更多
关键词 PRETREATMENT corn leaf corn stalk xylan removal enzymatic digestibility
下载PDF
Effects of protein and lignin on cellulose and xylan anaylses of lignocellulosic biomass 被引量:4
19
作者 James MacLellan Rui Chen +3 位作者 Zhengbo Yue Robert Kraemer Yan Liu Wei Liao 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2017年第6期1268-1275,共8页
Interactions of lignocellulosic components during fiber analysis were investigated using the highly adopted compositional analysis procedure from the National Renewable Energy Laboratory(NREL),USA.Synthetic feedstoc... Interactions of lignocellulosic components during fiber analysis were investigated using the highly adopted compositional analysis procedure from the National Renewable Energy Laboratory(NREL),USA.Synthetic feedstock samples were used to study the effects of lignin/protein,cellulose/protein,and xylan/protein interaction on carbohydrate analysis.Disregarding structural influence in the synthetic samples,lignin and protein components were the most significant(P〈0.05)factors on cellulose analysis.Measured xylan was consistent and unaffected by content variation throughout the synthetic analysis.Validation of the observed relationships from synthetic feedstocks was fulfilled using real lignocellulosic feedstocks:corn stover,poplar,and alfalfa,in which similar results have been obtained,excluding cellulose analysis of poplar under higher protein content and xylan analysis of alfalfa under higher protein content.The results elucidated that according to their protein and lignin contents of different lignocellulosic materials,accuracy of the NREL method on cellulose and xylan analyses could be improved by applying a stronger extraction step to replace water/ethanol extraction. 展开更多
关键词 lignocellulosic biomass CELLULOSE XYLAN LIGNIN PROTEIN
下载PDF
High Oxygen Nanocomposite Barrier Films Based on Xylan and Nanocrystalline Cellulose 被引量:5
20
作者 Amit Saxena Thomas J.Elder +1 位作者 Jeffrey Kenvin Arthur J.Ragauskas 《Nano-Micro Letters》 SCIE EI CAS 2010年第4期235-241,共7页
The goal of this work is to produce nanocomposite film with low oxygen permeability by casting an aqueous solution containing xylan,sorbitol and nanocrystalline cellulose.The morphology of the resulting nanocomposite ... The goal of this work is to produce nanocomposite film with low oxygen permeability by casting an aqueous solution containing xylan,sorbitol and nanocrystalline cellulose.The morphology of the resulting nanocomposite films was examined by scanning electron microscopy and atomic force microscopy which showed that control films containing xylan and sorbitol had a more open structure as compared to xylan-sorbitol films containing sulfonated nanocrystalline cellulose.The average pore diameter,bulk density,porosity and tortuosity factor measurements of control xylan films and nanocomposite xylan films were examined by mercury intrusion porosimetry techniques.Xylan films reinforced with nanocrystalline cellulose were denser and exhibited higher tortuosity factor than the control xylan films.Control xylan films had average pore diameter,bulk density,porosity and tortuosity factor of 0.1730 μm,0.6165 g/ml,53.0161% and 1.258,respectively as compared to xylan films reinforced with 50% nanocrystalline cellulose with average pore diameter of 0.0581 μm,bulk density of 1.1513 g/ml,porosity of 22.8906% and tortuosity factor of 2.005.Oxygen transmission rate tests demonstrated that films prepared with xylan,sorbitol and 5%,10%,25% and 50% sulfonated nanocrystalline cellulose exhibited a significantly reduced oxygen permeability of 1.1387,1.0933,0.8986 and 0.1799 cm^3×μm/m^2×d×k Pa respectively with respect to films prepared solely from xylan and sorbitol with a oxygen permeability of 189.1665 cm^3×μm/m^2×d×k Pa.These properties suggested these nanocomposite films have promising barrier properties. 展开更多
关键词 NANOCOMPOSITES XYLAN Nanocrystalline cellulose Oxygen barrier
下载PDF
上一页 1 2 3 下一页 到第
使用帮助 返回顶部