纳米银对秸秆腐解过程中元素和成分含量的影响

试验以玉米秸秆为材料,采用静态培养方法,对添加过不同浓度纳米银溶液的玉米秸秆腐解过程中元素和物质成分含量的变化进行了分析,研究纳米银对秸秆腐烂的影响。结果表明,与对照相比,添加纳米银溶液的处理碳元素和木质纤维素含量降低的速率明显减缓,氮元素含量升高速率显著降低,说明纳米银对环境中的微生物具有明显的抑制作用,纳米银在防止秸秆腐烂方面具有重要作用。     

The influence of xylanase on the fermentability,digestibility, and physicochemical properties of insoluble corn-based fiber along the gastrointestinal tract of growing pigs

In theory, supplementing xylanase in corn-based swine diets should improve nutrient and energy digestibility and fiber fermentability, but its efficacy is inconsistent. The experimental objective was to investigate the impact of xylanase on energy and nutrient digestibility, digesta viscosity, and fermentation when pigs are fed a diet high in insoluble fiber (>20% neutral detergent fiber; NDF) and given a 46-d dietary adaptation period. A total of 3 replicates of 20 growing gilts were blocked by initial body weight, individually housed, and assigned to 1 of 4 dietary treatments: a low-fiber control (LF) with 7.5% NDF, a 30% corn bran high-fiber control (HF; 21.9% NDF), HF + 100 mg xylanase/kg (HF + XY [Econase XT 25P; AB Vista, Marlborough, UK]) providing 16,000 birch xylan units/kg; and HF + 50 mg arabinoxylan-oligosaccharide (AXOS) product/kg (HF + AX [XOS 35A; Shandong Longlive Biotechnology, Shandong, China]) providing AXOS with 3–7 degrees of polymerization. Gilts were allowed ad libitum access to fed for 36-d. On d 36, pigs were housed in metabolism crates for a 10-d period, limit fed, and feces were collected. On d 46, pigs were euthanized and ileal, cecal, and colonic digesta were collected. Data were analyzed as a linear mixed model with block and replication as random effects, and treatment as a fixed effect. Compared with LF, HF reduced the apparent ileal digestibility (AID), apparent cecal digestibility (ACED), apparent colonic digestibility (ACOD), and apparent total tract digestibility (ATTD) of dry matter (DM), gross energy (GE), crude protein (CP), acid detergent fiber (ADF), NDF, and hemicellulose (P < 0.01). Relative to HF, HF + XY improved the AID of GE, CP, and NDF (P < 0.05), and improved the ACED, ACOD, and ATTD of DM, GE, CP, NDF, ADF, and hemicellulose (P < 0.05). Among treatments, pigs fed HF had increased hindgut DM disappearance (P = 0.031). Relative to HF, HF + XY improved cecal disappearance of DM (162 vs. 98 g; P = 0.008) and NDF (44 vs. 13 g; P < 0.01). Pigs fed xylanase had a greater proportion of acetate in cecal digesta and butyrate in colonic digesta among treatments (P < 0.05). Compared with LF, HF increased ileal, cecal, and colonic viscosity, but HF + XY decreased ileal viscosity compared with HF (P < 0.001). In conclusion, increased insoluble corn-based fiber decreases digestibility, reduces cecal fermentation, and increases digesta viscosity, but supplementing xylanase partially mitigated that effect.     

秸杆中半纤的维素结构及分离新方法综述

主要介绍了秸秆中半纤维素与木质素，纤维素和蛋白质之间的化学连接方式，以及碱抽提、碱性过氧化氢抽提和辅助碱抽提等3种新型半纤维素分离方法，综述了近年来农作物秸秆半纤维素分离方法的研究新进展。     

41种葡萄枝条废弃物中膳食纤维及营养成分研究

研究不同品种的葡萄枝条的基本组成成分含量,并对不同品种、不同来源的葡萄枝条中各组分含量的差异性进行比较。以41种葡萄枝条为试验材料,对膳食纤维、果胶、半纤维素、纤维素、木质素,可溶性蛋白、可溶性糖进行测定。结果表明:部分葡萄品种的枝条中同一组分的含量存在显著差异。41种葡萄枝条中纤维素的含量范围为284.2～418.0mg/g;半纤维素的含量范围为7.6～25.6mg/g;果胶的含量范围为81.6～209.6mg/g;木质素的含量范围为283.6～491.6mg/g。总膳食纤维的含量范围为927.0～981.2mg/g,可溶性膳食纤维的含量范围为81.0～108.2mg/g,不溶性膳食纤维的含量范围为801.4～904.4mg/g,蛋白质的含量范围为4.928～8.627mg/g,可溶性糖的含量范围为47.9～186.7mg/g。葡萄枝条中含有较高的膳食纤维,不同品种的葡萄枝条中同一组分含量不同,部分品种间有显著差异。     

半纤维素酯化和醚化改性研究进展

近些年,从可再生资源获得新的功能性材料引起了广泛关注。半纤维素通过改性后可替代传统化石材料制备新型功能材料。从酯化和醚化两方面论述半纤维素化学改性的研究现状,并对半纤维素改性应用前景进行展望。半纤维素酰氯酯化赋予半纤维素斥水性能而酸酐酯化赋予亲水性能,羧甲基化、甲基化、季碱化和苄基化在半纤维素醚化方面取得很大进展。新的技术应用将会更大程度提高改性半纤维素取代度,为发掘其鲜为人知的用途提供了新窗口。     

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。     

厚壁毛竹结构性成分含量特征

采用范氏洗涤纤维法分别测定竹叶、竹枝和竹秆中的纤维素、半纤维素和木质素的含量,研究了厚壁毛竹不同部位和不同生长时间的结构性成分含量变化特征。结果表明：竹叶中纤维素含量低于半纤维素含量[分别为（27．71±5．82）％、（38．02±5．76）％],而竹枝和竹秆中纤维素含量均明显高于半纤维素含量;各部位按纤维素含量、木质素含量和结构性成分含量总和的高低分别为：竹秆中部、竹秆基部、竹秆梢部、竹枝和竹叶,而半纤维素含量相反。方差分析表明,不同部位间的纤维素、半纤维、木质素含量及其总和的差异均达到极显著水平（ F＞F0．01,P＜0．01）;不同生长时间的结构性成分含量及其总和的差异相对较小,仅木质素含量的差异达到显著性水平（ F＝4．777,P＝0．012）。研究结果为厚壁毛竹的利用奠定基础。     

秸秆饲料中纤维素、半纤维素和木质素的定量分析研究

拟定了秸秆饲料中纤维素、半纤维素和木质素的定量分析方法。结果表明:将中性洗涤剂法改为pH2洗涤剂法,更便于过滤;将酸性洗涤剂法改为2 mol/L盐酸洗涤剂法,使ADF中半纤维素含量显著降低,提高了纤维素和半纤维素的测定准确度。与Van Soest方法相比有操作简便、快速,定量准确性高的特点。     

Effects of Inbreeding and Genetic Variation on Forage Quality Traits and Dry Matter Yield in Dactylis glomerata L. Subspecies

Cultivated 4× clones, 2× germplasm and their respective S; progeny were utilized in this study. Dry matter yield and forage quality data (in vitro dry matter disappearance, cell wall constituents, total nitrogen) were obtained on composited vegetative plant material harvested during four successive 4-week growth periods in the greenhouse. There was no detectable average inbreeding effect for any of the traits. The group mean of the diploids was significantly lower for in vitro dry matter disappearance than the tetraploid group mean. However, two out of six diploid 51 families exceeded the highest tetraploid family for this trait. The diploids had significantly higher cell wall constituents than tetraploids except for acid detergent lignin. There was more variation for any trait at the diploid level than at the tetraploid level among S₁ families as well as within families. Dry matter yield and total nitrogen were significantly correlated in diploids and in tetraploids. However, little variation was detected lot total nitrogen at either ploidy level. The results suggest that selection for improved quality in progeny from interploidy crosses may be more efficient by first selecting at the diploid level followed by scaling to the tetraploid level, rather than selection at the tetraploid level after hybridization.     

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...