木质素降解菌的筛选及混合菌发酵降解秸秆的研究

农作物秸秆是农业生产的副产品,也是一项重要的生物资源。由于其成分结构的特殊性所导致的难降解问题,一直成为了转化利用秸秆的难题。目前,利用混合菌将秸秆纤维素转化为蛋白质、乙醇、乙酸、乳酸等研究已逐渐为人们所重视。本文通过马铃薯琼脂平板培养、马铃薯液体摇瓶培养和稻草秸秆固态发酵,从6株常见的食用白腐菌中筛选出了生长优势较强、产漆酶酶活高的平菇HF。为了让秸秆得到更好的降解和利用,采用平菇和康氏木霉二步混合发酵法;通过不同的组合方式,发现H6-T10组合得出的降解效果最好,其木质素降解率达到44.77%,纤维素降解率达到41.48%。     

微生物转化秸秆饲料

正秸秆作为农作物的主要副产品,是一种重要的可再生资源。利用微生物的降解能力,将秸秆转化为动物可利用的饲料,对于解决人畜争粮具有重大意义。微生物处理法具有提高营养价值、改善适口性、绿色无污染、能耗低等优点,是当前最具应用潜力和发展前景的秸秆饲料生产技术。本刊2013年第4期刊登了吴文韬、鞠美庭等发表的文章"一株纤维素降解菌的分离、鉴定及对玉米     

中国秸秆菌业现状及研究进展

农作物秸秆稍加处理后,即为栽培食药用菌的高效基质原料。我国作为一个农业大国,秸秆资源极为丰富,为食用菌产业的蓬勃发展提供了坚实的物质基础。依据“三物循环”的理念,结合食用菌栽培基质特性和食用菌产业发展现状等分析,阐明了秸秆菌业的概念,分析了目前我国秸秆菌业的秸秆资源利用现状以及秸秆菌业发展前景等问题,深入探讨了我国秸秆菌业在秸秆废弃物利用方面的巨大潜力。旨在推动农业资源的高效循环利用,实现食用菌产业的绿色、可持续发展。     

家蝇幼虫对两种秸秆的消化及利用研究

本文旨在探明家蝇Musca domestic幼虫对高粱秸秆和小麦秸秆营养成分利用和木质纤维素的降解情况,以及不同配比秸秆饲料对家蝇生物学指标的影响,为今后产业化利用家蝇来生物降解秸秆类有机废弃物奠定理论基础.本研究采用70％高粱秸秆粉、70％麦秸秆粉和纯麦麸作为饲料,每种饲料各设置对照组、发酵组和家蝇幼虫取食组3种处理,检测并分析3种饲料各处理组中一般营养成分和木质纤维素的含量及变化;同时采用7种配比饲料喂养家蝇,观察各组家蝇不同发育阶段的体长、体重、存活率和发育历期等.结果表明:(1)3种饲料的各处理组中,一般营养成分和木质纤维素的含量均呈现:对照组>发酵组>家蝇取食组的趋势,此外除高粱秸秆组粗蛋白外,其余各组成份均差异显著(P<0.05);(2)小麦秸秆的木质纤维素含量>高粱秸秆>麦麸,且各组间均差异显著(P<0.05);(3)在相同秸秆配比条件下,高粱秸秆饲喂的家蝇其各虫态体长、体重、总存活率和发育历期均要优于麦秸秆喂养,且总存活率和发育历期与麦麸喂养相比差异不显著(P>0.05);(4)纯高粱秸秆喂养下家蝇仍能保持正常的生长发育,而在90％小麦秸秆喂养下,家蝇则无法存活.综上所述,家蝇适合作为生物转化器用于秸秆、尤其是高粱秸秆的降解,且降解效果优于单纯的微生物发酵降解,研究结果为今后规模化利用家蝇降解秸秆类有机废弃物提供了理论依据和科学基础.     

产纤维素酶耐高温真菌在有机肥料生产中的潜在价值

农作物秸秆是农作物生产中一种富含氮、磷、钾、钙、镁和有机质等有效成分的可再生资源,我国每年的农作物秸秆废弃物产量巨大,因此,如何有效地"转废为宝",实现对农作物秸秆废弃物的再利用一直是我国学者关注的问题.秸秆堆腐还田技术是有机废弃物再利用的理想途径之一,其作用原理是利用微生物的分解作用,促使农作物秸秆发酵腐熟后成为优良的绿色有机肥.农作物秸秆属于高纤维素含量废弃物,且纤维素的结构复杂、降解困难,如何加速纤维素的分解是实现农作物秸秆堆肥物料快速分解、达到腐熟的关键问题.已有研究表明,在堆肥中接种高温或耐高温降解菌可促进有机物降解,提高堆肥高温期温度,延长高温期,加快堆肥腐熟.     

发酵农作物秸秆生产生物饲料的优良菌株的筛选

目前世界面临的主要问题是粮食问题,而粮食问题的关键是人畜争粮。如何解决饲料蛋白严重缺乏的矛盾已逐渐引起人们重视。美国的研究人员研究成功一种微生物发酵农作物秸秆生产优质饲料的新技术,该技术可使产物的蛋白含量提高３～４倍。哈萨克斯坦科学院研制出一种微生物发酵剂,它对农作物秸秆的纤维素降解率相当高。加拿大学者选育出显微半知菌发酵农作物秸秆,经５ｄ发酵能获得蛋白质含量为１４％的发酵产物。英国的研究人员选育出一种普通野生真菌处理农作物秸秆,能使秸秆的可消化率提高６０％。我国是农业大国,每年约产６亿吨农作物…     

混料设计优化红平菇菌丝生长的“以草代木”配方

【背景】"以草代木"不仅能解决食用菌栽培的原料来源问题,还能有效缓解菌林矛盾。【目的】利用不同的农业剩余物优化出可替代木屑做主料进行红平菇菌丝培养的"以草代木"配方。【方法】采用混料配比的设计方法,利用小麦秸秆、玉米秸秆、大豆秸秆、花生秸秆、油菜秸秆、水稻秸秆、玉米芯共7种农业剩余物做主料培养红平菇,对其菌丝在基料生长过程中纤维素酶、多酚氧化酶和漆酶的酶活进行测定,分析并优化出适合红平菇生长的"以草代木"配方。【结果】大豆秸秆最适合红平菇菌丝的生长,小麦秸秆次之;油菜秸秆基质中红平菇多酚氧化酶活性最高。配方优化得出一个适合红平菇菌丝生长的"以草代木"配方:小麦秸秆55.3%、大豆秸秆19.7%、麦麸15.0%、玉米面5.0%、豆粕3.0%、石灰1.0%、石膏1.0%。【结论】优化出一个适合红平菇菌丝生长的基质配比,为红平菇进行"以草代木"设施化栽培提供理论依据。     

西部七省区作物秸秆资源分布及利用现状

基于统计数据和农户调研数据,估算了西部七省区农作物秸秆资源量、秸秆资源密度、人均占有秸秆数量和秸秆养分资源量,分析了秸秆资源量变化趋势(1997—2011年)及资源分布利用现状,讨论了制约秸秆综合利用的因素和提高秸秆利用率的途径.结果表明:2009年西部七省区农作物秸秆资源理论数量达到8.82×107t,谷物类秸秆占总量的63.1%;秸秆养分还田总量达1.20×106t,还田率达50.5%.西部七省区秸秆资源密度低于全国平均水平,人均秸秆占有量略高于全国平均水平.秸秆资源主要用作燃料、饲料、工业原料、基质和直接还田,分别占资源总量的33.8%、29.3%、5.2%、1.8%和13.5%,焚烧和废弃的秸秆分别占秸秆资源的11.1%和5.3%.     

微生物降解秸秆木质素的研究进展

我国秸秆资源丰富，每年产生逾8亿t作物秸秆。通过秸秆直接还田或肥料化还田不仅可以减少化肥的施用量，缓解农业污染压力，还能实现农作物秸秆的循环利用。木质素结构复杂，且与纤维素和半纤维素相互缠绕，因此秸秆的自然腐解过程中，木质素是主要的限速因子，为了提高降解效率，木质素降解菌的发掘和降解机制也逐渐成为研究热点。本文综述了降解木质素的真菌和细菌的研究现状，对比其真菌和细菌降解特性的优缺点并分析复合降解菌群的优势。随后对木质素降解酶系的酶学性质、在不同微生物中的表达特性进行总结，对木质素降解机制及衍生芳烃代谢路径的研究进展进行综述。最后整理木质素降解微生物在秸秆肥料化技术中的应用进展，并探讨了微生物降解秸秆木质素的应用前景和未来的研究方向。     

玉米秸秆栽培平菇技术的研究

利用玉米秸秆栽培平菇有着原料来源广、就地取材等优点,但由于玉米秸秆切成段后栽培平菇,保水性差,体积大,产量低,为了克服这些不足之处,在无棉区开辟代料栽培平菇的新途径,我们采用玉米秸秆粉碎后栽培平菇,取得了较好的效果。     

曲江县的牧草生产与养牛业发展关系的研讨

对曲江县养牛业发展有重要作用的几方面问题,如建立大面积的牧草生产基地,果园间种牧草和利用现有秸秆资源作饲料等进行了调查研究和分析讨论．此外,还阐述和讨论了农、牧业结合,相互促进、发展农村生产和经济等方面的问题。     

The balance of nitrogen and composition of proteins inPleurotus ostreatus grown on natural substrates

The balance of nitrogen and nitrogen compounds in Pleurotus ostreatus, cultivated on waste materials, corn straw and maize residues, was investigated. The results show that this organism has a considerable ability to fix atmospheric nitrogen, fixing 312 g of total nitrogen per 100 kg dry weight. When recalculating with respect to a decrease of the substrate during growth of the organism a value of 9.7 mg per 1 g of the decrease in material is obtained. Fruiting bodies, as well as the produced substrate contain 17-19 amino acids. In the produced substrate the content of the protein nitrogen represents only 30% of the total. It can concluded that Pleurotus ostreatus yields a suitable raw material in the food industry and possibly also a fodder based on the basis of solid, cellulose-containing wastes.     

Belowground carbon input and translocation potential of fodder radish cover-crop

We compared the soil C input potential of a common catch-crop (fodder radish) established in 6-year-old direct-drilled (DD) plots with adjacent conventionally tilled (CT) plots on a Danish sandy loam soil by use of ¹⁴C-isotope labelling techniques. Intact monoliths of soil with actively growing fodder radish seedlings were extracted in Autumn of 2008 from DD and CT field plots and labelled with ¹⁴CO₂ at different time intervals during fodder radish growth. Labelled monoliths were then sampled 6 and 100 days after termination of labelling by clipping above-ground biomass at soil level and separating below-ground components into macro-roots and macro-root-free soil at 0?C10, 10?C25 and 25?C45 cm soil depth. Using fodder radish ¹⁴C data and the preceding spring barley biomass yield data we estimated C input from the spring barley-fodder radish cycle in addition to evaluating the effect of the removal of spring barley harvestable straw on soil C input. Potential soil C input under straw removal scenarios with and without an established fodder radish crop was also evaluated. Relative to other depths, over 70% of labelled below-ground C was found in the 0?C10 cm soil depth in both DD and CT treatments for each of the two samplings. For both macro-root and macro-root-free soil and in both tillage treatments, labelled C decreased significantly with depth (P?<?0.05). A decline of labeled C in macro-root but an increase of labeled C in macro-root-free soil was observed from day 6 to day 100 for both tillage treatments. Over the autumn-winter growing period, total below-ground C input by fodder radish within the 0?C45 cm soil depth was approximately 1.0 and 1.2 Mg C ha^?1 for CT and DD, respectively. We used data from 100 days after labelling, which coincided with the incorporation of the field fodder radish biomass, to estimate that the total fodder radish contribution to below-ground C after biomass incorporation would range between 1.6 and 1.7 Mg C ha^?1 for DD and CT, respectively. The figures for spring barley straw removal with fodder radish establishment would be between 4.9 and 5.1 Mg C ha^?1, while with no fodder radish establishment, C input to the soil would range between 3.2 Mg C ha^?1 and 3.4 Mg C ha^?1, which is approximately 0.6 Mg C ha^?1 lower than the 4 Mg C ha^?1 biomass C input required to maintain long-term soil organic C. In comparison, under straw retention and fodder radish catch-crop establishment the total spring barley and fodder radish C input would be approximately 6.1 and 6.5 Mg C ha^?1 for DD and CT, respectively. We conclude that fodder radish catch-crops have a potential for mitigating against soil C depletion resulting from export of cereal straw to other uses.     

促分解菌剂对还田玉米秸秆的分解效果及土壤微生物的影响

为了探明促分解菌剂的应用对还田玉米秸秆的促分解效果及对土壤微生物群落结构的影响,选用3组促分解菌剂,编号依次为ND、NK和NS,于2009年10月至2010年4月期间,在河北省农林科学院辛集实验站冬小麦-玉米轮作田对玉米秸秆还田地进行了接种试验。在接种后的15、25、145和160 d分别测定秸秆残重率和秸秆残渣中C/N,结果表明与未施菌剂对照(CK)相比,3组菌剂均在一定程度上加快了玉米秸秆的分解,其中以菌剂ND促分解效果最好,NK次之,NS较差,三者的最高促分解效果分别比CK提高了14.3%、7.7%和1.6%,主要促分解效果都出现在早期(前25 d),且菌剂促进秸秆残渣中C/N降低的效果也在早期明显。采用变性梯度凝胶电泳技术(DGGE)检测菌剂对玉米秸秆降解过程中土壤细菌和真菌群落结构的影响,结果表明,与不接种CK相比,接种菌剂主要在早期对土壤细菌和真菌的群落结构产生较大的影响,而后期对土壤微生物群的影响不明显。秸秆还田后接种促分解菌剂,能在接种早期有效加快秸秆分解,而随接种后时间的推进,其促进效果逐渐减弱,与之对应,土壤微生物群落结构早期差异明显,其后差异逐渐减小。     

冬季覆盖作物秸秆还田对双季稻田根际土壤微生物群落功能多样性的影响

微生物群落功能多样性是土壤质量变化重要的指标,不同作物类型的秸秆还田措施对土壤微生物群落功能多样性具有明显的影响。以位于双季稻主产区不同冬季覆盖作物-双季稻种植模式大田定位试验田为研究对象,以冬闲-双季稻种植模式为对照(CK),应用Biolog-GN技术开展黑麦草-双季稻(Ry)、紫云英-双季稻(Mv)、油菜-双季稻(Ra)和马铃薯-双季稻(Po)种植模式条件下不同冬季覆盖作物秸秆还田后对双季稻田根际土壤微生物功能多样性影响的研究。研究结果表明,早稻和晚稻成熟期,与CK处理相比,冬季覆盖作物秸秆还田处理增加了稻田土壤碳源平均颜色变化率(AWCD),以Po处理AWCD均为最高,均显著高于Ry和CK处理。不同冬季覆盖作物秸秆还田处理土壤微生物代谢多样性指数表现出明显的差异,早稻成熟期,Po处理的Richness、Shannon和McIntosh指数均为最高,其次为Ry、Mv和Ra处理,CK处理最低;晚稻成熟期,各处理的Richness、Shannon和McIntosh指数大小顺序均表现为PoRaMvRyCK。土壤微生物碳源利用的主成分分析结果表明,各冬季覆盖作物秸秆还田处理根际土壤微生物利用的主要碳源为氨基酸类和糖类物质,不同处理间碳源利用类型有差异。冬季覆盖作物秸秆还田措施有利于提高双季稻田根际土壤微生物对碳源的利用能力、物种丰富度和均匀度。     

Beta-adenosine, a bioactive compound in grass chaff stimulating mushroom production

Fructification and yield of the edible mushrooms Pleurotus pulmonarius and Stropharia rugosoannulata are clearly enhanced when wheat straw is supplemented with 30% Lolium perenne grass chaff. The bioactive compound in the methanol extract of grass chaff was identified as beta-adenosine. In vitro biological activity tests showed that 0.012 mg of beta-adenosine per ml of medium stimulated earlier fructification of Pleurotus pulmonarius. Mushroom fruiting trials showed that when 12 mg beta-adenosine was added to 1 kg wet wheat straw, primordia of Pleurotus pulmonarius appeared two days earlier and primordia of Stropharia rugosoannulata appeared 18 days earlier when compared to pure wheat straw substrate. This concentration of beta-adenosine had no impact on the mushroom yield of Pleurotus, but resulted in a 2.2 fold increase in yield for Stropharia. beta-Adenosine at 25 mg per kg wet wheat straw increased the yield of Pleurotus with 52% and the yield of Stropharia with 258%, but this concentration delayed primordial formation in Pleurotus.     

Oyster mushroom cultivation with rice and wheat straw

Cultivation of the oyster mushroom, Pleurotus sajor-caju, on rice and wheat straw without nutrient supplementation was investigated. The effects of straw size reduction method and particle size, spawn inoculation level, and type of substrate (rice straw versus wheat straw) on mushroom yield, biological efficiency, bioconversion efficiency, and substrate degradation were determined. Two size reduction methods, grinding and chopping, were compared. The ground straw yielded higher mushroom growth rate and yield than the chopped straw. The growth cycles of mushrooms with the ground substrate were five days shorter than with the chopped straw for a similar particle size. However, it was found that when the straw was ground into particles that were too small, the mushroom yield decreased. With the three spawn levels tested (12%, 16% and 18%), the 12% level resulted in significantly lower mushroom yield than the other two levels. Comparing rice straw with wheat straw, rice straw yielded about 10% more mushrooms than wheat straw under the same cultivation conditions. The dry matter loss of the substrate after mushroom growth varied from 30.1% to 44.3%. The straw fiber remaining after fungal utilization was not as degradable as the original straw fiber, indicating that the fungal fermentation did not improve the feed value of the straw.     

秸秆还田的效果、问题与对策

农作物秸秆还田是改善土壤理化性质、增加微生物和酶活性、促进作物增产的有效措施,也是农作物秸秆资源化利用的一种重要方式,但秸秆还田也可能会导致作物出苗率降低、加重作物病虫害发生、引起土壤重金属等有毒有害物质积累等负面影响。目前秸秆以直接还田为主,亦有少量通过堆沤、垫圈等方式间接还田。秸秆在土壤中的腐解速度及还田效果主要取决于秸秆的化学组成特别是C/N、土壤微生物状况、土壤温度及水分含量等。下一步,必须强化秸秆还田方法、快速腐解条件及制剂、对下季作物病害影响及防控、农机农艺配套、缓解全球变化能力等研究,完善相关技术与方法,促进秸秆还田快速推广应用。     

Cultivation of Oudemansiella tanzanica nom. prov. on agricultural solid wastes in Tanzania

The edible mushroom Oudemansiella tanzanica nom. prov., which is new to science, has been studied as a potential crop to reduce agricultural solid wastes and increase domestic mushroom production. The substrates sawdust, sisal waste and paddy straw supplemented with chicken manure resulted in the highest biological efficiencies of any mushroom cultivated in Tanzania so far. In addition, the mushroom has one of the shortest cultivation cycles at 24 d. Despite the fact that the mushroom extracts substantial amounts of nutrients, the spent substrate can be used as fodder, as a soil conditioner and fertilizer and in bioremediation.