有效微生物菌群(EM)对蟹鲈混养模式下养殖水体菌群结构的影响

为探究定期添加有效微生物菌群(EM)对蟹鲈混养养殖水质和菌群结构的影响,实验对混养水体进行了Ⅰ期(4月10号)、Ⅱ期(4月20号)、Ⅲ期(4月30号)和Ⅳ期(5月10号)的监测,并通过水质理化指标、16S rRNA基因高通量测序技术分析了每个时期的水质和菌群结构.高通量测序结果显示,实验期间水体主要优势菌门为变形菌门、...     

瘤胃微生物总DNA快速提取法研究

本文介绍了一种简便快速地提取瘤胃微生物细胞总DNA的方法,该法是对提取植物的CTAB法进行改进而成。与经典反复冻融 SDS/蛋白酶K裂解法相比,该法可在数小时内高效地提取瘤胃内容物总DNA,经琼脂糖凝胶电泳对所提取瘤胃微生物总DNA进行检测,证明所获得的瘤胃总DNA符合分子生物学操作要求。     

Quantifying the impact of microbes on soil structural development and behaviour in wet soils

There is evidence that microbial populations play an important role in altering soil pore geometry, but a full understanding of how this affects subsequent soil behaviour and function is still unclear. In particular the role of microorganisms in soil structural evolution and its consequence for pore morphological development is lacking. Using a combination of bio-chemical measurements and X-ray Computed Tomography (CT) imaging, a temporal comparison of microscale soil structural development in contrasting soil environments was made. The aim was to quantify the effect of microbial activity in the absence of other features likely to cause soil deformation (e.g. earthworms, roots etc.) on soil structural development in wet soils, defined by changes in the soil porous architecture i.e. pore connectivity, pore shape and pore volume during a 24 week period. Three contrasting soil textures were examined and changes compared between field soil, sterilised soil and a glucose enhanced soil treatment. Our results indicate that soil biota can significantly alter their microhabitat by changing soil pore geometry and connectivity, primarily through localised gaseous release. This demonstrates the ability of microorganisms to modify soil structure, and may help reveal the scope by which the microbial-rich rhizosphere can locally influence water and nutrient delivery to plant roots.     

Medium-term effects of corn biochar addition on soil biota activities and functions in a temperate soil cropped to corn

Biochar addition to soil has been generally associated with crop yield increases observed in some soils, and increased nutrient availability is one of the mechanisms proposed. Any impact of biochar on soil organisms can potentially translate to changes in nutrient availability and crop productivity, possibly explaining some of the beneficial and detrimental yield effects reported in literature. Therefore, the main aim of this study was to assess the medium-term impact of biochar addition on microbial and faunal activities in a temperate soil cropped to corn and the consequences for their main functions, litter decomposition and mineralization. Biochar was added to a corn field at rates of 0, 3, 12, 30 tons ha⁻¹ three years prior to this study, in comparison to an annual application of 1 t ha⁻¹.Biochar application increased microbial abundance, which nearly doubled at the highest addition rate, while mesofauna activity, and litter decomposition facilitated by mesofauna were not increased significantly but were positively influenced by biochar addition when these responses were modeled, and in the last case directly and positively associated to the higher microbial abundance. In addition, in short-term laboratory experiments after the addition of litter, biochar presence increased NO₂ + NO₃ mineralization, and decreased that of SO₄ and Cl. However, those nutrient effects were not shown to be of concern at the field scale, where only some significant increases in SOC, pH, Cl and PO₄ were observed.Therefore, no negative impacts in the soil biota activities and functions assessed were observed for the tested alkaline biochar after three years of the application, although this trend needs to be verified for other soil and biochar types.     

EM微生态制剂对仔猪的保健效果观察

试验开展EM微生态制剂对仔猪增重效果、仔猪腹泻的控制效果、环境除臭及蚊蝇孽生繁殖的消除效果等研究,结果表明:(1)EM制剂对仔猪具有良好的育肥增重效果。试验组平均增重比对照组多1.981 kg,差异显著(P<0.05);(2)EM的添加对仔猪腹泻具有良好的控制效果。试验组死亡率为5%,治愈率为75%;对照组死亡率为40%,自愈率为30%;(3)EM微生态制剂能抑制腐败菌的生长繁殖,有明显消除粪便臭味,减少蚊蝇孽生繁殖,从而净化环境,减少污染,改善仔猪生长环境。结论:EM微生态制剂对仔猪具有保健效果。     

江苏沿海滩涂土壤中细菌培养方法的优选

研究选择江苏省盐城市王港附近一垂直于海岸线的断面(土壤含盐量近似递减),分别采集自海水淹没线至内陆农田相隔一定距离的土样(编号为Soil-1、Soil-2、Soil-3、Soil-4和Soil-5),代表海水淹没、裸滩、盐蒿、芦苇/白茅和农田植被环境。设计9种培养方案,包括不同浓度的NB培养基,配以不同浓度的海水,添加和不添加环腺苷(cAMP),平板和液体两种培养方式,用变性凝胶电泳检测可培养菌的多样性,并评价和优选培养方案。结果表明,经过自然脱盐的耕种土壤,培养基中配入10%的海水可培养菌多样性指数最高;其余4种土壤配入100%海水多样性指数最高。添加cAMP不能明显提高微生物可培养性。低浓度培养基较过去惯用浓度的培养基更有利于提高可培养微生物的多样性。液体培养基明显优于固体培养基。在10-8或更高稀释度下,液体培养的试管底部有粘稠状沉淀物为微生物细胞,但培养基清澈。将有沉淀物的试管视为阳性试管,用最或然数方法计的土壤中细菌数量可达1012g?1。提出培养分离滩涂土壤培养方案为:用1/10浓度的NB配以100%海水的液体培养基培养,用相同浓度和成分的固体培养基分离,培养25d左右。     

瑞香狼毒根际疣孢青霉菌YL 52次生代谢产物的研究

旨在了解瑞香狼毒根际疣孢青霉菌YL-52(Penicillium verruculosum YL-52)次生代谢产物的组成和结构。利用溶剂萃取、反复硅胶柱层析分离和Sephadex LH-20柱层析纯化等方法从发酵液中分离出化合物,并采用IR、ESI-MS、1 H NMR、13 C NMR和DEPT等方法综合完成结构的分析鉴定。从发酵液乙酸乙酯部分中分离出5个化合物,化合物2和化合物3分别被鉴定为熊果酸和扁枝衣二酸,并首次证明瑞香狼毒根际微生物-疣孢青霉菌发酵液中存在熊果酸和扁枝衣二酸。     

有效微生物群对玉米植株生长与代谢的影响

有效生物群(EM)处理促进了玉米植株的生长发育,使苗期与孕穗期的植株高于对照,叶面积指数和比叶重也不所增加;从根系活力和植株代谢能力来看,EM 处理具有刺激生长,促进发育,协调生理机能的作用。     

苗床添加EM菌肥对烟草幼苗生长及抗逆酶活性的影响

【目的】研究苗床添加EM菌肥对烟草幼苗生长发育及抗逆酶活性的影响,以探索培育烟草壮苗的新措施。【方法】以红花大金元和云烟85为供试材料,采用室内模拟试验,研究烟草育苗基质中添加不同质量分数EM菌肥(0(T0),5%(T1),10%(T2),15%(T3))对烟草幼苗根系形态及活力、生物量和抗逆酶活性的影响。【结果】添加EM菌肥后云烟85幼苗总根长、平均直径、总根体积、总根表面积及红花大金元总根长较对照均显著增加,随添加菌肥质量分数的增加,云烟85平均直径、总根体积、总根表面积增幅不明显;不同径级根系总长表现为≤3mm细根增幅显著;EM菌肥显著提高幼苗根系活力,红花大金元以T2最强,平均达425.45μg/(g·h),增幅74.0%,T3、T1其次,而云烟85表现为T1T2T3T0。添加EM菌肥后,红花大金元幼苗总生物量以T2(881.1mg/株)最大,增幅57.5%,云烟85总生物量随菌肥质量分数的增大有增加趋势。添加EM菌肥后烟草幼苗过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)活性显著增强,T2各酶活均达最高或次高。不同烟草品种对EM菌肥的响应存在差异,EM菌肥处理后红花大金元根系活力、抗逆酶活性增幅均大于云烟85,尤以叶片抗逆酶活性的表现更为突出。【结论】育苗基质中添加质量分数10%的EM菌肥可显著提高红花大金元和云烟85幼苗根系活力,促进细根生长,增加幼苗干物质积累,增强幼苗抗逆性,建议在生产中推广应用。