一株产铁载体香蕉拮抗内生细菌的分离及鉴定

研究了羽叶决明(Chamaecrasta nictitans)替代麸皮栽培鸡腿菇(Coprinus comatus)对其产量、绝对生物学效率、基物失重、呼吸消耗及木质纤维素转化的影响。结果表明,羽叶决明牧草替代20 %麸皮(B2)栽培鸡腿菇的产量和绝对生物学效率最高,分别为235.2 g/袋和8.86 %。覆土前和采收后的基物失重、呼吸消耗都以B6为最高,分别为13.50 %、13.50 %和35.03 %、30.71 %,其纤维素转化率也最高,为33.61 %;木质素转化率以B1为最高,达78.25 %;半纤维素转化率以B2为最高,为44.10 %。回归分析表明,羽叶决明替代麸皮栽培鸡腿菇的产量、绝对生物学效率和半纤维素转化率与替代比例呈抛物线相关,而基物失重、呼吸消耗及木质素、纤维素转化率与替代比例呈线性相关。     

亚麻快速生物脱胶技术研究--Ⅲ.麻茎化学成分在快速生物脱胶过程中的变化

在实验室条件下,利用亚麻脱胶茵Ym68',对亚麻原茎进行快速脱胶试验,定期测定了麻茎中的脱胶菌活茵量、水溶物、果胶、半纤维素、木质素和纤维素等指标.结果表明,亚麻原茎中水溶物、果胶、半纤维素、木质素和纤维素含量分别为16.57%、7.82%、19.4%、18.4%和21.01%;脱胶完成时,果胶、半纤维素和木质素脱除率分别为82.1%、17.0%和11.4%;在接种后发酵2h内,亚麻麻茎中的水溶物由16.57%迅速降至7.93%;接种后发酵2h-4h,脱胶茵活茵量的增加幅度最大,为5.88倍;麻茎中果胶、半纤维素和木质素的含量均随着时间的延长而降低.     

茶果的主要化学成分及其在成熟过程中的变化规律(英文)

通过对不同成熟度的茶果(果壳、种壳及种仁)的分析测定,基本摸清了茶果各部分的主要化学成分及其在成熟过程中的变化规律。在成熟的茶果中,组成果壳的主要成分为半纤维素(15.91%)、纤维素(15.23%)、木质素(36.75%)及茶单宁(13.96%);组成种壳的主要成分为半纤维素(19.87%)、纤维素(27.50%)和木质素(42.23%);组成种仁的主要成分是茶籽油(35.19%)、淀粉(19.89%)、皂素(12.38%)和蛋白质(10.93%)。同时,作者还对茶果的主要成分的利用问题进行了讨论。     

利用亚麻屑栽培黑木耳试验研究

以"牡耳1号"为供试菌种,采用亚麻屑替代木屑作为基质栽培黑木耳的培养料,进行黑木耳栽培。试验设6个配方处理,亚麻屑替代量分别为0,15%,30%,45%,60%,78%。结果表明:利用亚麻屑部分替代阔叶木屑作为基质栽培黑木耳可行,采用麻屑替代阔叶木屑作为栽培基质,可促进黑木耳菌丝体生长速度,加快菌丝愈合,促进黑木耳原基形成,添加一定量的亚麻屑可提高黑木耳子实体的产量和生物学效率。亚麻屑替代量在45%以下均适合栽培黑木耳,其中亚麻屑替代量为30%的配方产量最高。     

玉米秸秆苞叶与茎皮中磨木木质素和木素-碳水化合物复合体的傅里叶红外光谱分析

通过傅立叶红外光谱(FT-IR)对玉米秸秆苞叶和茎皮中的磨木木质素(MWL)和木素-碳水化合物复合体(LCC)的结构进行表征,明确玉米秸秆不同部位木质纤维素的结构。采用改良的Bj?rkman方法,分别从玉米秸秆苞叶与茎皮部位提取分离到MWL和LCC,并通过FT-IR对其结构进行表征和分析。结果表明,两个部位中的MWL组成明显不同,茎皮木质素中的苯丙烷侧链上的支链结构以及苯环结构比重均高于苞叶木质素,而羟基、甲基和共轭羰基结构低于苞叶木质素。茎皮木质素结构中以紫丁香基结构单元为主,而苞叶木质素中主要以愈创木基结构单元为主。两个部位的LCC结构存在差异,苞叶LCC中的羟基含量高于茎皮LCC,甲基、亚甲基含量较茎皮LCC低;茎皮LCC中木质素与半纤维素连接强度明显高于苞叶LCC,因此可推断,茎皮中木质素与纤维素的分离难度大于苞叶。     

利用能源植物斑茅纤维固态发酵产纤维素酶及其糖化的研究

以能源植物斑茅(Erianthus arundinaceus)为材料,对其纤维成分、产酶条件和糖化条件进行了分析。结果表明:斑茅含有纤维素43.77%、半纤维素28.57%、木质素11.01%;对斑茅进行预处理后,纤维中纤维素的含量提高至72.54%,半纤维素含量降低至13.02%,木质素的含量降低至3.34%。利用预处理的斑茅纤维进行固态发酵产酶,其最佳的产酶条件为:茅麸比1∶3,固液比1∶2,氮源(脲)0.75%,初始pH 5.0,32℃发酵培养72 h;相对于利用未经预处理的斑茅纤维为原料,其FPA酶活提高210.9%,达到20.74 U/g,CMC酶活提高239.1%,达到218.26 U/g。以纤维素酶对斑茅纤维进行糖化,糖化率达到40.60%。     

几种热带豆科饲用灌木在贵州南部地区的生态适应性研究

引进7个豆科饲用灌木在贵州南部地区进行生态适应性研究,结果表明:在贵州南部地区能正常开花结实的有多花木蓝、羽叶决明、木豆、猪屎豆和云南羊蹄甲等5个品种;抗旱、耐瘠薄、鲜干草产量、种子产量较高的品种为多花木蓝(年均鲜干产量为54.24 t/hm2和16.49 t/hm2,种子产量为2 430.04 kg/hm2)、羽叶决明(年均鲜干产量为31.54 t/hm2和6.47 t/hm2,种子产量为1 727.53 kg/hm2)、木豆(年均鲜干产量为15.44 t/hm2和4.90 t/hm2,种子产量为2 345.89 kg/hm2),其粗蛋白质含量为16.77%~26.07%,是贵州南部地区值得推广利用的优良豆科饲用灌木。     

蒸汽爆破预处理降解香蕉茎秆纤维素组分的研究

分析测试香蕉茎秆总固体含量(TS)和挥发性固体含量(VS)及香蕉茎秆固体剩余物中纤维素、半纤维素、木质素含量;采用蒸汽爆破法对香蕉茎秆进行预处理,探讨不同压力及维压时间下对香蕉茎秆中半纤维素、纤维素、木质素组分的降解程度,分析蒸汽爆破预处理优缺点。试验结果表明,经过蒸汽爆破预处理后,香蕉茎秆的组分被不同程度破坏,当压力为3.5 MPa,维压时间为4 min时,香蕉茎秆中半纤维素含量由预处理前13.33%降至4.36%,降解率高达67.29%,纤维素含量由48.33%降至39.15%,降解率为18.99%,木质素含量由14.62%降至6.52%,降解率为55.40%,总体含量由76.28%降至50.03%,降解率为34.41%。说明蒸汽爆破技术对香蕉茎秆固体剩余物的预处理效果比较显著,有一定的优越性。     

碱预处理提高香蕉茎秆厌氧消化产气性能的研究

为有效利用香蕉茎秆资源,提高其厌氧消化效率,采用碱法对香蕉茎秆固体剩余物进行预处理,探讨不同预处理条件下香蕉茎秆厌氧消化产气性能的影响。结果表明：当NaOH浓度为8%时,对香蕉茎秆原料半纤维素、纤维素、木质素降解率达最高,分别为22.5%、9.1%、13.7%;6% NaOH处理组30 d累积产气量最高可达3 775 mL,比对照组提高24.2%,单位干物质产气量达377.5 mL/g TS。碱预处理可有效提高香蕉茎秆产气潜力。     

基于示范样地实际倒伏样本的小麦抗倒机制解析

为解析影响小麦倒伏发生的关键因子与内在机制,基于示范样地,选择不同养分管理下实际倒伏三块样本(1个高倒伏田块和2个低倒伏田块,养分管理方式分别为普通化肥深施、普通化肥撒施和缓控释肥深施),对小麦株型、倒伏节间的形态、组分及维管束数量、根系构型、土壤养分供应等进行比较分析。结果表明,在同等氮肥施用量与相同播种密度下,化肥深施田块（D-CF）的倒伏率高于化肥撒施（M-CF）和缓控释肥深施田块（D-RCU）。茎基部节间是小麦倒伏发生的主要部位,节间越长,倒伏高度越高。高倒伏样本田块（D-CF）的株高显著高于M-CF和D-RCU田块,分别增加15.7%和15.1%,且D-CF田块的穗重与茎鞘叶重比最高。不同田块倒伏节间（茎基部节间）的外径、壁厚均无显著差异,但高倒伏田块D-CF的茎基部节间维管束面积和数量均低于低倒伏田块,较M-CF减少8.7%和9.0%,较D-RCU降低了11.8%和5.9%,且纤维素、半纤维素与木质素的含量显著低于D-RCU田块。D-CF田块的根尖数显著高于两低倒伏田块,且根系总长与表面积显著高于D-RCU田块。D-CF田块的5~10、10~15和15~20 cm土层的速效氮含量均最高。经相关性分析,倒伏率与株高呈显著正相关,与倒伏节间维管束数量及半纤维素、纤维素与木质素的总含量均呈显著负相关。株高分别与根系总根长、根尖数及5~20 cm土壤速效氮含量呈极显著或显著正相关,而维管束数量与5~10 cm土壤速效氮含量呈显著负相关,纤维素及木质素含量均与5~20 cm土壤速效氮含量呈显著负相关,半纤维素含量则与10~15 cm土壤速效氮含量呈显著负相关。受田间小麦根系构型及中下层土壤速效氮含量影响,株高和茎基部节间维管束数量及三素（半纤维素、纤维素、木质素）含量是小麦倒伏风险的主要影响因子。     

Production of carboxymethylcellulose fibers from waste lignocellulosic sawdust using NaOH/NaClO2 pretreatment

In this study, waste lignocellulosic sawdust was converted to carboxymethylcellulose (CMC) by the combination process of an inorganic base (NaOH) and a weak acid (monochloroacetic acid, MCA). Optimum conditions for the pretreatment were studied on the basis of lignin and hemicellulose removal. NaOH and MCA concentration, reaction time, and operating temperature were the parameters studied to acquire the optimized conditions for the production of CMC. Degree of substitution (DS) and solubility were greatly influenced by the changes in the experimental conditions. DS increased on increasing the concentration of NaOH and MCA but the effect was more profound during the NaOH loading. A maximum DS of 0.5 was obtained on the treatment with 20 % NaOH and 20 % MCA concentration at 50 °C, 150 rpm for 4 h. 1.28 g CMC/g cellulose was obtained at the optimized set of conditions. Structural information of cellulose and CMC was obtained using IR spectroscopy and the surface morphology was studied using field emission scanning electron microscopy (FESEM). Carboxymethylcellulose showed lower crystallinity than the native cellulose extracted from sawdust which was studied using X-ray diffraction.     

金针菇松杉木屑菌糠栽培猴头菇的技术研究

为降低猴头菇生产成本和解决松杉木屑工厂化栽培金针菇菌糠利用问题,研究了金针菇菌糠营养成分和不同配方对猴头菇产量及经济效益的影响。结果显示:金针菇菌糠含有9.8%粗蛋白、32.3%粗纤维、1.2%粗脂肪、17.9%木质素和7.7%灰分;筛选出配方2是最佳的配方,比例分别为金针菇菌糠38%、棉籽壳20%、玉米芯30%、麸皮10%、碳酸钙2%,其产量和利润分别比对照组、配方1、配方3和配方4提高了9.67%、25.00%、6.12%、8.40%和115.91%、48.44%、46.15%、25.00%。为金针菇菌糠用于猴头菇大面积栽培提供了科学依据。     

Processing of Lespedeza stalks by pretreatment with low severity steam and post-treatment with alkaline peroxide

The steam pre-treatment with low severity preserves valuable biomass components, and further delignification with alkaline peroxide could improve hydrolysis. A combination of low severity steam pretreatment and alkaline peroxide post-treatment of Lespedeza stalks was investigated. The post-treatment of steam-pretreated Lespedeza stalks with alkaline peroxide significantly increased the cellulose content and changed the structure of the cellulose-rich fractions. A glucose yield of 503.5 mg g⁻¹ raw material from enzyme hydrolysis was obtained when the steam-pretreated material (184 °C for 4 min) was post-treated with 2% hydrogen peroxide at 60 °C for 24 h with a substrate concentration of 3.3%. Its hydrolysis yield is 88.8%, which is higher than that of samples processed by steam pretreatment alone (63.7%). The samples obtained by post-treatment with alkaline peroxide were found to have a smoother surface and looser structure in scanning electron microscopy images. The isolated lignin preparations had a yield range from 10.9 to 14.7 (% dry matter). The lignin was characterized by thermogravimetric analysis/differential thermal analysis, Fourier transform infrared spectroscopy, and gel permeation chromatography. Alkaline peroxide treatment increased the thermal stability of lignin, and decreased the amounts of all functional groups. Depolymerization and repolymerization occurred during the alkaline peroxide treatment.     

竹基质与菌种密度对棘托竹荪产量及营养品质的影响

以棘托竹荪为研究对象,采用正交试验设计,探讨竹荪培养基质量与菌种密度对其产量和营养成分的影响,筛选最佳配比组合,旨在为竹荪种植提供科学的技术支撑。结果表明:鲜菇平均产量3.51 kg/m²、粗蛋白含量18.78%、粗纤维含量21.19%、总糖含量37.79%。不同处理组合间产量、粗蛋白和总糖差异极显著（P<0.01）,粗纤维差异显著（P<0.05）。菌种密度和基质量各因素水平间仅产量差异显著,营养成分无显著差异,其中600 g/m²菌种密度的竹荪产量极显著大于400、800 g/m²,为4.54 kg/m²;16.0 kg/m²基质量的产量显著高于8.0、12.0 kg/m²,为3.95 kg/m²,3种主要营养成分随菌种量和基质量水平的增加呈异质性变化,二者的交互作用显著影响粗蛋白含量（P<0.05）;极差分析结果显示,菌种量对竹荪产量、粗蛋白和粗纤维含量的影响大于基质,而对总糖含量影响与之相反。不同处理组合的种植支收比为(1∶3.77)~(1∶9.32),其中以每平方米林地采用16.0 kg基质种植600 g菌种收益最高,收益达54.9元/m²,支收比1∶6.62,但投入成本与产量收益呈非完全正比关系。本研究认为,尽管基质量和菌种种植密度不会单方面显著改变竹荪营养成分,但选择合适的配比对提高竹荪产量和优化支收比都具有重要意义。     

The influence of supermasscolloider on the morphology of sugarcane bagasse and bagasse cellulose

Sugarcane bagasse (SB) was subjected to mechanical and chemical treatments in order to investigate the influence of both treatments on the morphology of cellulose extracted from SB. Samples treated with supermasscolloider (SMC) showed a slight increase in the cellulose content and a highest content after chemical treatment. Furthermore, SEM and XRD results revealed a decline in the fibre average diameter (10-2 μm) and sheet-like fibrils from mechanically treated samples, while the crystallinity index values increased for both mechanical and chemical treatment. FTIR and chemical composition analysis confirmed a partial removal of hemicellulose and lignin by supermasscolloider, whereas the chemical treatments removed a significant amount and this was effectively reflected on the improved thermal stability of cellulose mechanically and chemically treated respectively.     

Evaluation of dyes decolourisation by the crude enzyme from Pleurotus sajor-caju grown on sorghum seed media

The extracellular enzymes from Pleurotus sajor-caju were studied for lignin degrading enzyme patterns and dye decolourisation potential. Laccases are major ligninolytic enzymes excreted by the fungus. The results from a native-PAGE revealed that there were at least two isoenzymes. The crude enzyme had a pH and a temperature optimum at 6.0 and 40 degrees C, respectively when 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) was used as substrate. The pH and thermal stability were at 5.0 and 30 degrees C. The pH optima for decolourisation of Indigo Carmine and Methyl Red were at 5.0 and 6.0, respectively. Indigo Carmine could be decolorized efficiently above 90% within 180 min, whereas Methyl Red could be decolorized only 3.5%. High efficiency decolourisation of Indigo Carmine makes this fungus to be a promise choice in biological treatment of waste water containing Indigo Carmine.     

Chemical composition of grape stalks of Vitis vinifera L. from red grape pomaces

The chemical composition and the structure of macromolecular components of grape stalks from red grape pomaces have been evaluated. These are composed mainly of cellulose (30.3%), hemicelluloses (21.0%), lignin (17.4%), tannins (15.9%) and proteins (6.1%). Among hemicelluloses the xylan was the most abundant (ca. 12%). The parameters of cellulose unitary cell, average diameter of nanofibrils and the degree of crystallinity (75.4%) were assessed by X-ray scattering analysis. The xylan was partially acetylated glucuronoxylan (DS = 0.49) possessing the Xylp:MeGlcpA ratio of 25:1. The lignin of grape stalks was suggested to be of HGS type with H:G:S molar proportion of 3:71:26 as revealed by analysis of nitrobenzene oxidation products. Among alkali soluble condensed tannins procyanidins prevailed over prodelphinidins. The abnormal response of grape stalks to kraft pulping, leading to poorly delignified fibrous material, was attributed to a particular lignin structure and it structural association with other macromolecular components of grape stalks.     

Interacting effects of yak dung deposition and litter quality on litter mass loss and nitrogen dynamics in Tibetan alpine grassland

The effects of grazing‐induced dung deposition on plant growth and soil attributes are well established, but little is known about dung effects on litter decomposition. Here, we tested effects of yak dung on litter decomposition and nutrient content in a Tibetan alpine meadow. We incubated litter of four common alpine meadow species using litter bags in the field. Two low‐quality species (Kobresia capillifolia and Elymus nutans) with low nitrogen (N), high C/N and Lignin/N, and two high‐quality species, (Saussurea nigrescens and Thermopsis lanceolata) were incubated in monoculture with and without dung addition. Mass loss of leaf litter, fibre fraction (cellulose, hemi‐cellulose and lignin), N and phosphorus (P) were measured after 6, 12 and 18 months of incubation in the field. Dung addition significantly increased decomposition constants for low‐quality litter species, but not for high‐quality litter species. Dung addition promoted cellulose and hemi‐cellulose loss, but lignin loss was not affected by dung addition, except after 12 months for high‐quality litter species. Dung reduced N immobilization after 6 months and did not affect subsequent release in low‐quality litter species, and promoted N release after 6 and 12 months in high‐quality litter species. Regardless of litter quality, dung increased P release after 6 and 12 months. Our results suggest grazing‐induced dung deposition may accelerate C and nutrient turnover, primarily through increasing the mass loss of low‐quality litter, P release from litter and N release from high‐quality litter. The mechanisms underlying the effects of dung deposition need to be clarified in future studies.     

Chemical characterization of various parts of nipa palm (Nypa fruticans)

The current study was initiated to characterize various parts of nipa palm (Nypa fruticans) to establish whole utilization of this biomass as potential raw material for fuels and chemicals. Nipa consisting of frond, shell, husk and leaf was chemically characterized for cellulose, hemicellulose, lignin, starch, protein, extractives and inorganic constituents for its each part. The total chemical composition showed that the cellulose and hemicellulose contents were in the range of 28.9-45.6 wt% and 21.8-26.4 wt%, respectively. The hemicellulose was rich with glucuronoxylan. The lignin content was 19.4-33.8 wt% with the highest lignin content found in leaf. The alkaline nitrobenzene oxidation products showed that nipa palm lignin mainly consists of guaiacyl and syringyl propane units with a small amount of p-hydroxyphenylpropane unit. Besides the main chemical components, starch, protein and extractives were also present in significant amounts from 2 to 8 wt%. Additionally, the ash content was high from 5.1 to 11.7 wt%, consisting of the major inorganic elements being Na, K and Cl with minor inorganic elements of Mg, Ca, Si, P, S and Al. Overall, each part of the nipa palm has its individual superior characteristics and could be exploited as lignocellulosic resources for fuels and chemicals.