秸秆厌氧干发酵产沼气的研究

本试验以玉米秸、稻草、烟叶杆、木薯杆为代表的秸秆作为原料，在温度38℃，采用批量发酵工艺进行高浓度厌氧发酵产气研究。试验结果表明，玉米秸、稻草、烟叶杆及木薯杆的TS产气率分别为413ml／g、33ml／g、333ml／g、222ml／g，而VS产气率分别为470ml／g、387ml／g、426ml／g、24ml／g。     

高通量测序分析玉米秸秆与牛粪联合发酵阶段微生物多样性变化

研究比较不同配比微生物菌剂添加对牛粪-玉米秸秆联合沼气发酵的影响,并采用高通量测序技术对添加了最佳菌剂的沼气发酵液中微生物多样性进行分析。结果表明,最佳玉米秸秆-牛粪发酵条件:微生物菌剂配比为蜡样芽孢杆菌、荧光假单胞菌、枯草芽孢杆菌、松嫩假单胞菌(质量比3∶2∶3∶2),在此条件下最高沼气产率和甲烷产率分别达到了72和39 m L/g VS,最高累积产沼气产率和甲烷产率分别达到了778和532 m L/g VS;高通量测序结果表明,细菌中的拟杆菌门(Bacteroidetes)的数量最为丰富,是最主要的优势类群,在沼气发酵过程中的相对丰度变化趋势为增加,由发酵初期33. 8%增加到发酵末期的43. 6%;真菌中子囊菌门(Ascomycota)的数量最为丰富,是最主要的优势类群,沼气发酵过程中相对丰度变化趋势为先增加后降低,由发酵初期65. 7%增加到发酵中期的84. 7%,又降到发酵末期的66. 8%。     

碱处理对玉米秸秆固态厌氧消化过程中菌群结构的影响

从微生物菌群的动态变化来阐述厌氧消化过程已成为近年的研究热点之一.该文从微生物菌群变化的角度对碱预处理促进纤维质原料厌氧消化性能的原因进行了分析.通过对碱预处理组及对照组典型厌氧消化阶段进行取样、高通量测序后,比较二者在菌群结构方面的差异.结果表明,底物种类及碱处理均对厌氧消化菌群结构有显著影响.实验中共鉴定出10个门...     

玉米秸秆不同预处理产沼气对比试验

玉米秸秆直接经过预处理A（对照），玉米秸秆用复合菌剂绿秸灵预处理B，玉米秸秆用纤维素酶A和纤维素酶B混合预处理C，玉米秸秆和牛粪尿混合预处理D，4种不同预处理方式的玉米秸秆产沼气对比试验。结果表明：用复合菌剂处理过的玉米秸秆试验B，用纤维素酶处理过的玉米秸秆试验C和玉米秸秆与牛粪尿混合试验D，平均产气量均高于直接经过预处理的玉米秸秆对照试验A，分别提高了33．47％，35．76％，36．65％；处理D的秸秆产沼气比处理B和处理C的秸秆产沼气早2天，比处理A（对照）的纯秸秆产沼气早5天。     

厌氧消化污泥干化后热解半焦性质

市政污水污泥厌氧消化再经干化处理后得到的干污泥(D S S)是一种具备一定热值的生物质原料.在常压下采用固定床线性升温的方法热解DSS,利用元素分析、BET、SEM、差热分析、FT-IR等测试手段研究DSS热解后气、液、固三相产物产率以及污泥热解半焦性质.结果表明:通过控制热解温度可以控制三相产物的分布,低于500℃是...     

不同预处理方法对剩余污泥厌氧消化产沼气过程的影响

研究了不同预处理方法对剩余污泥固态法厌氧消化产沼气过程的影响.结果表明:不同的预处理方法均可不同程度地提高产气量和甲烷含量.其中,经酶法处理后,剩余污泥前4 h产气速率最快,平均每小时为3.29 mL/g;经热处理后,剩余污泥累积产气量最多,为45.80 mL/g,比对照提高了230%;而经微波处理后,剩余污泥所产沼气中甲烷质量分数最高,为62.26%,比对照增加了130%.     

氨氮质量浓度对餐厨垃圾厌氧消化产沼气的影响

实验研究不同氨氮质量浓度对餐厨垃圾厌氧消化过程的影响。实验结果表明:氨氮质量浓度对餐厨垃圾消化过程中出现的两个产气高峰均有显著影响,最高氨氮质量浓度组最大产气速率分别是对照组的44.8%和45%,产气高峰出现时间比对照组分别延迟6 h和42 h。氨氮质量浓度上升导致反应体系中总有机碳去除率降低,由此计算出氨氮抑制餐厨垃圾厌氧消化过程的半抑制浓度为7 860 mg/L。氨氮质量浓度的升高导致挥发性脂肪酸过量积累,其利用速率也相应减缓。     

物理法处理对香蕉秸秆沼气发酵能力影响分析

在中温(37±1)℃条件下,对经物理预处理后获得的纤维长度分别为0.23、2.70、4.10和4.12 cm的4种香蕉秸秆样品进行了批次厌氧发酵试验,考察了物理预处理对香蕉秸秆沼气发酵情况的影响,并分析了利用香蕉秸秆在工业规模制备沼气的可行性。结果表明,物理预处理强度的增强可以提高沼气发酵的日产气量及累积产气量,但对沼气中甲烷含量没有显著影响(甲烷含量在55.54%与63.88%之间)。纤维长度为0.23和2.70 cm时,高日产气量分别为333.6和319.8 mL/d,比4.10 cm和4.12 cm的样品高32.11%34.92%;沼气产率分别为306.49和340.13 mL/g(VS added),比4.10 cm和4.12 cm的样品高8.29%~17.36%。与小麦和玉米秸秆相比,利用香蕉秸秆制备沼气具备较好的应用前景。     

天津静海区秸秆沼气工程运行模式与管理经验

一、项目简介 为了贯彻农业部发展秸秆沼气的精神，本刊记者赵梦随中国农业大学林聪教授与北京化工大学李秀金教授赴天津市静海区进行了采访调研。据了解，天津市静海区目前有两处大型秸秆沼气工程，一处位于四党口村，另一处位于南柳木村，工程均采用农业部规划设计研究院研发的秸秆一体化两相厌氧消化工艺（CTP），由天津旭粲燃气设备有限公司具体建设。     

降解玉米秸秆产纤维素酶和木质素酶菌种的筛选

筛选能降解玉米秸秆产生纤维素酶和木质素酶的菌种,并测定纤维素酶系和木质素酶系的相关酶活.经过筛选得到10株菌株,经鉴定为:Penicillium sp、Altemaria sp、Aspergillus fumigatus、Aspergillus sp、Pestalotiopsis sp、Tricherderma sp、Cephalsporium sp、Pleurotus sp.酶活分析显示,筛选得到的10株菌都有CMC酶、滤纸酶、微晶纤维素酶、Mn过氧化氢酶、漆酶等酶活性;筛选得到的茵株都具有较全面的降解玉米秸秆所需要的酶系,具有较好的玉米秸秆生物降解的研究价值.     

Short communication: Purple corn (Zea mays L.) stover silage with abundant anthocyanins transferring anthocyanin composition to the milk and increasing antioxidant status of lactating dairy goats

The present study used 16 multiparous lactating Saanen dairy goats (body weight, 41.80 ± 2.92 kg; mean ± standard deviation) with healthy and symmetrical udders. Goats were divided into 2 blocks of 8 goats based on milk yield averaged from 75 d in milk in a randomized completed block design. The 2 study groups were the control (CSSS), in which goats were fed sticky corn stover silage, and the treatment (TPSS), in which goats were fed anthocyanin-rich purple corn (Zea mays L.) stover silage (PSS). The results indicated that the TPSS group led to an elevation in the content of milk lactose relative to the CSSS. The inclusion of anthocyanin-rich PSS had no effect on the level of 5 particular anthocyanins [i.e., cyanidin-3-glucoside, delphinidin, cyanidin, pelargonidin (Pel), as well as total anthocyanins in milk]. The pelargonidin-3-glucoside and malvidin were unable to be detected in both groups. However, the TPSS resulted in higher levels of peonidin (Peo) and malvidin-3-O-glucoside (M3G) compared with the control. Moreover, goats receiving TPSS exhibited a higher level of superoxide dismutase (SOD) in plasma and milk relative to the CSSS. Interestingly, some positive correlations were detected between the certain milk components [i.e., fat and total solids as well as fat and solids-not-fat (SNF); protein and SNF; and total solids and SNF]. In addition, the positive correlations were observed between individual anthocyanins (cyanidin-3-glucoside, delphinidin, Peo, M3G, cyanidin, and Pel) and total anthocyanins. Specifically, stronger positive correlations were noted between several antioxidant enzymes and anthocyanin composition in milk (total antioxidant capacity and Pel; SOD and Peo as well as SOD and M3G). Taken together, PSS with abundant anthocyanins can transfer anthocyanins to the milk and enhance the amount of antioxidants in lactating dairy goats.     

紫玉米秸秆青贮饲料对热应激奶山羊能量利用、血浆代谢和抗氧化参数的影响

试验采用4×4拉丁方试验设计,选取8只体况良好的经产萨能奶山羊[体重(41.50±1.84)kg;平均数±标准差]随机分为4组,四种日粮处理分别为(粗饲料均占日粮干物质50％):粗饲料为稻草组(NC)、黏玉米秸秆青贮饲料组(PC1)、黏玉米秸秆青贮饲料+1 g/d商业紫玉米花青素提取物组(PC2)及紫玉米秸秆青贮饲料组...     

Unravelling the influence of sulfate loading on enhancing anaerobic co-digestion of corn stover and bio-kerosene production wastewater

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A comparison of processed conventional corn silage to unprocessed and processed brown midrib corn silage on intake, digestion, and milk production by dairy cows

We studied the effects of mechanical processing and type of hybrid on the nutritive value of corn silage for lactating cows. Treatments were brown midrib (BMR) corn silage that was unprocessed (U-BMR), BMR corn silage that was processed (P-BMR), and a conventional corn silage that was processed (P-7511). All silages were harvested at a theoretical chop length of 19 mm. The chemical compositions of the silages were similar among treatments except that BMR silages were lower in lignin and higher in protein than P-7511. Brown midrib silages had greater 30-h in situ and in vitro NDF digestion than did P-7511, and processing had no effect on 30-h in situ and in vitro fiber digestion, but it increased in situ starch digestion after 3 and 12 h of incubation. Both processed silages had a smaller proportion of particles >1.91 cm and fewer whole corn kernels compared with unprocessed silage. Lactating cows were fed a total mixed ration (TMR) consisting of 42% of each silage type, 40% concentrate, 10% alfalfa silage, and 8% alfalfa hay (DM basis). Cows fed TMR containing P-BMR ate more DM and produced more milk than cows fed P-7511. At feeding, the TMR containing U-BMR had a larger proportion of particles >1.91 cm when compared with the TMR of cows fed processed silages, and after 24 h the difference was even greater, indicating that cows fed unprocessed corn silage sorted more. Cows fed TMR with P-7511 and P-BMR had greater total tract digestibility of organic matter, crude protein, and starch compared with cows fed U-BMR. In vivo digestibility of neutral detergent fiber was greatest for cows fed P-BMR when compared with the other treatments.     

北疆春播、麦后复播青贮玉米物质生产和温光生态效应利用的比较--测试文章

以新玉15号为供试品种,研究了春播和麦后复播青贮玉米（复播1期,6月30日播种;复播2期,7月10日播种）在产量、干物质积累和光温气候资源利用等方面的差异。结果表明：春播、复播1期、复播2期的群体干物质产量分别为15 615、17 615、14 671 kg·hm^-2,春播、复播1期、复播2期鲜重产量53 988、67 251、68 327 kg·hm^-2;复播青贮玉米生育期明显缩短,光合有效辐射和≥10℃积温较春播少;复播1期苗期、穗期、灌浆期均处于最适温度范围之内;春播、复播1期、复播2期的LAI峰值为5.01、5.72、6.36,总光合势分别为2.45×10⁶、2.84×10⁶、3.37×10⁶ m²·d^-1·hm^-2。复播青贮玉米的产量潜力主要在于大口期之前生育期优越的光温资源条件,且大口期之前干物质积累速率较春播快。     

Improving corn silage quality in the top layer of farm bunker silos through the use of a next-generation barrier film with high impermeability to oxygen

This study examined the effect on the fermentation, chemical, and microbiological quality of corn silage covered with a new-generation high oxygen barrier film (HOB) made with a special grade of ethylene-vinyl alcohol (EVOH) compared with a standard polyethylene film (PE). Two bunkers (farms 1 and 2) were divided into 2 parts lengthwise so that half of the silo would be covered with PE film and the other with HOB film. Plastic net bags with fresh chopped corn were buried in the upper layer (close to and far from the wall) and in the central part of the bunkers. During spring-summer consumption, the bags were unloaded, weighed, and subsampled to analyze the dry matter (DM) content, neutral detergent fiber and starch contents, pH, lactic and monocarboxylic acids, yeast and mold counts, aerobic and anaerobic spore-former counts, and aerobic stability. We also determined the economic benefit of applying the novel covering. The top layer of silage conserved under the HOB film had a higher lactic acid content and lower pH; lower counts of yeasts, molds, and aerobic and anaerobic spore-formers; higher aerobic stability; and lower DM losses than the silage conserved under the PE film. The use of the HOB film prevented almost all of the silage in the upper layer from spoiling; only 2 out of 32 samples had a mold count > 6 log₁₀ cfu/g. This led to a net economic gain when the HOB film was used on both farms due to the increased DM recovery and reduced labor time required to clean the upper layer, even though the HOB film cost about 2.3 times more than the PE film. Furthermore, use of the HOB film, which ensures a longer shelf life of silage during consumption, reduced the detrimental effect of yeasts, molds, and aerobic and anaerobic spore-formers on the nutritional and microbiological quality of the unloaded silage.     

Rapid degradation of the Cry3Bb1 protein from Diabrotica‐resistant Bt‐corn MON88017 during ensilation and fermentation in biogas production facilities

BACKGROUND: Insect‐resistant transgenic corn is meeting a growing adoption in Europe. Corn is also the major substrate for biogas production, which has vastly increased in recent years. In areas with high insect pest pressure Bt‐corn silage will consequently be fed into biogas production facilities. To assess the potential risks of transgenic plants as energy crops we investigated the fate of the coleopteran‐specific protein Cry3Bb1 from MON88017 corn in the utilization chain of a farm‐scale biogas production facility using ELISA. RESULTS: The mean Cry3Bb1 protein content in chaffed MON88017 plant material was 15 µg g^?1. In silage the content decreased rapidly, with less than 20 ng g^?1 detectable after 8 months. From the start of fermentation in the biogas reactor, only trace amounts of Cry3Bb1 could be detected. Conventional corn harvested alongside MON88017 with the same equipment showed a presence of transgenic plant material of around 0.5%. Analyses performed at two laboratories showed consistent and systematic differences in the concentrations of Cry3Bb1 measured with ELISA due to methodical differences. CONCLUSIONS: An extensive degradation of Cry3Bb1 was observed in silage despite differences in ELISA measurements. The potential risk associated with the use of MON88017 silage is discussed on this basis. Copyright © 2008 Society of Chemical Industry     

体外产气法评定青贮玉米秸与豆秸组合的瘤胃发酵特性

探讨青贮玉米秸与豆秸组合对瘤胃发酵参数的影响,以确定适宜的饲料组合比例。本试验将青贮玉米秸与豆秸分别按0∶100、20∶80、40∶60、60∶40、80∶20、100∶0的比例进行组合,利用体外瘤胃发酵技术,分析不同比例组合对产气量、pH值、氨态氮、菌体蛋白和瘤胃干物质、中性洗涤纤维和酸性洗涤纤维的影响,并计算出各组合的单项组合效应值和综合组合效应值,进而筛选出两种饲料组合的适宜比例。结果表明：青贮玉米秸-豆秸不同比例组合后在产气量上差异显著（P〈0.05）,以80∶20时最大;各比例对体外瘤胃液pH值影响差异不显著（P〉0.05）;氨态氮质量浓度随青贮玉米秸比例的增加而增加,在40~50mg/dl变化;菌体蛋白质量浓度在两者比例为80∶20时最高;青贮玉米秸-豆秸不同比例组合的干物质、中性洗涤纤维和酸性洗涤纤维的瘤胃有效降解率均以80∶20时最大。在本试验条件下,以多项组合效应评定指数评定组合效应,青贮玉米秸与豆秸比例为80∶20时较为适宜,综合组合效应指数达到最大。