The Effect of Detopping the Field Bean Plants (Vicia faba L. minor) and Lack of the Pod Setting on the Symbiosis with Root Nodule Bacteria

The plants of field bean var. Nadwiślaνski were detopped after about 1 month since the beginning of flowering and after that all flower buds were removed from some plants. The effect of a change in the trophic balance on the setting and subsequent growth of root nodules was studied.
The removal of pods had the greater effect on the increase in the weight of the remaining organs than the detopping of plants. Detopping retarded the ageing of the plants and delayed the phase of the greatest reduction of the number of pods. The detopping of plants revealed their considerable compensative possibilities in terms of production of the pod weight and the potential of leaves for biomass production. The data obtained indicate that plant detopping may disturb the root–bacteria exchange of signals, necessary to initiate the nodule development, while the further growth of nodules depends, above all, on the amount of available photosynthates.
A very high correlation between the dry weight of the whole plant to the dry weight of leaves ratio and the weight of nodules was observed. It proves the importance of the trophic balance of the plant for the root nodule weight production.     

减氮对麦玉轮作农田土壤反硝化细菌群落结构和多样性的影响

探究减氮对华北地区麦玉轮作农田土壤反硝化细菌群落结构和多样性影响,为华北地区麦玉轮作农田氮肥管理提供技术支持,本研究以不施氮为对照（CK）,设置 2个施氮量,分别为常规施氮量（纯氮 300 kg·hm^-2,N2）、减氮 20%（纯氮 240 kg·hm^-2,N1）,提取土壤DNA,用nirS（细胞色素cd1-亚硝酸还原酶）、nirK（Cu-亚硝酸还原酶）引物扩增后采用MiSeq PE300测序技术,研究施氮量对麦玉轮作农田土壤性状及nirS、nirK反硝化细菌群落结构及多样性的影响。结果表明,3个处理nirS、nirK反硝化细菌α-多样性指数无显著差异,nirS反硝化细菌α-多样性高于nirK。减氮显著影响nirS、nirK反硝化细菌物种组成。减氮对nirS、nirK反硝化细菌门水平及nirK纲水平物种组成无显著影响,但显著降低了nirS反硝化细菌Deltaproteobacteria（δ-变形菌纲）相对丰度;减氮显著影响nirS、nirK属水平物种组成。硝态氮、速效磷、pH值是影响土壤nirS反硝化细菌属水平群落结构主要环境因子;pH值是影响土壤nirK反硝化细菌属水平群落结构的主要环境因子。研究表明,适量减氮不影响反硝化细菌α-多样性,但显著影响反硝化细菌属水平群落组成和群落结构,减氮主要是通过影响土壤性状及微生物群落结构进而影响农田土壤N₂O排放。     

Continuous Production of Biogenic Magnetite Nanoparticles by the Marine Bacterium Magnetovibrio blakemorei Strain MV-1T with a Nitrous Oxide Injection Strategy

Magnetotactic bacteria (MTB) produce magnetosomes, which are membrane-embedded magnetic nanoparticles. Despite their technological applicability, the production of magnetite magnetosomes depends on the cultivation of MTB, which results in low yields. Thus, strategies for the large-scale cultivation of MTB need to be improved. Here, we describe a new approach for bioreactor cultivation of Magnetovibrio blakemorei strain MV-1^T. Firstly, a fed-batch with a supplementation of iron source and N₂O injection in 24-h pulses was established. After 120 h of cultivation, the production of magnetite reached 24.5 mg∙L⁻¹. The maximum productivity (16.8 mg∙L⁻¹∙day⁻¹) was reached between 48 and 72 h. However, the productivity and mean number of magnetosomes per cell decreased after 72 h. Therefore, continuous culture in the chemostat was established. In the continuous process, magnetite production and productivity were 27.1 mg∙L⁻¹ and 22.7 mg∙L⁻¹∙day⁻¹, respectively, at 120 h. This new approach prevented a decrease in magnetite production in comparison to the fed-batch strategy.     

单液滴微萃取—毛细管气相色谱法测定水样中的硝基苯类化合物

[目的]建立快速、简便、高灵敏度的检测硝基苯类化合物的方法。[方法]建立单液滴微萃取-毛细管气相色谱法（SDME-GC）测定水样中的硝基苯类化合物。以外标法测定了硝基苯、2-硝基甲苯、3-硝基甲苯、4-硝基甲苯、3-硝基氯苯的标准工作曲线方程、检出限、线性范围,并在相同实验条件下测定了实际工业废水样中上述硝基苯类化合物的含量、加标回收率范围及相对标准偏差范围。[结果]5种硝基苯类化合物检出限很低,最小能达到8.9×10-4μg/ml,且均在较宽的线性范围内表现出良好的线性关系（相关系数均在0.99以上）。该方法的回收率、相对标准偏差符合要求。[结论]单液滴微萃取一毛细管气相色谱法预处理快捷、环保、价廉且富集效果好,操作简便、快速、准确、灵敏度高、线性范围较宽。     

蜜蜂肠道菌群的调节作用及影响因素

近年来, 蜜蜂数量的大量减少导致全球养蜂业面临重要的经济损失,并对农业各个方面造成了严重后果。最新的研究表明肠道菌群与宿主的健康息息相关。综述了肠道菌群的种类和特性,阐述了肠道菌群在蜜蜂等昆虫健康中的调节作用及影响肠道菌群的因素,并对今后的研究方向进行了展望。     

散尾葵提取物成分分析及抑菌作用

利用超声波提取和气质联用分析法,对散尾葵的提取物进行了组分和含量分析。结果表明,提取物含酸类化合物2种,占提取物总量的1.20%;醇类化合物3种,占提取物总含量 1.78%;酯类化合物5种,占提取物总量的7.11%;烷类化合物5种,占提取物总量的13.27%;醚类化合物2种,占提取物总含量 3.36%;酮类化合物1种,占提取物总含量 0.41% 。利用散尾葵提取物对10种居室空气中收集的细菌进行了抑菌性测定,对其中7种具有抑菌活性,而对放线菌、动性球菌、冷杆菌无抑制作用。对葡萄球菌和枯草芽孢杆菌抑菌力最强,125mg/mL浓度提取液抑菌率达到100%。     

粪便移植技术的应用研究

本文综述了粪便移植技术的的概念、由来、研究与进展、作用机理,展望了该技术在兽医上的应用前景,指出其在治疗动物营养代谢疾病、改善机体免疫力低下、增强屏障保护功能、调整机体能量平衡、治疗肥胖和II型糖尿病等方面的应用价值,旨在推广粪便移植疗法在兽医临床上应用。     

伊克昭盟牧草和饲料作物应用增产菌技术的试验

199年伊克昭盟引入了牧草和饲料作物增产菌这一技术,经过7年的试验,示范及推广,至今全盟该增产菌应用面积已达4．04万hm^2,本文通过7年来在两种不同生境下,对12种牧草及作物的不同物修期采用不同方法施用增产菌,以鲜草产量和种子产量为衡量标准来探讨增产菌对不同牧草及作物的增产效果,实验结果表明：增产菌技术的应用,促进了植物的生长,使植株长高,叶面积增大,加强了光合作用,在提高鲜草产量的同时也增加了籽实的产量,具有较强的推广价值,是一项在农牧区适用的增产技术。     

复合有机铁对母猪繁殖性能及其抗氧化能力的影响

为研究复合有机铁对母猪繁殖性能、血液理化指标及抗氧化能力的影响,试验选用体重接近、胎次接近、预产期一致的健康“长×白”二元杂母猪30头,随机分为3组,每组10个重复,每个重复1头母猪,3个处理组分别在基础日粮中补充硫酸亚铁、甘氨酸亚铁、复合有机铁。结果显示:较硫酸亚铁组,复合有机铁组产程缩短23.57%、胎产健仔数增加14.00%、初生窝重增加14.14%(P < 0.05);母猪血红蛋白含量、红细胞数和红细胞压积分别提高19.88%、10.53%、8.33%(P < 0.05);母猪抗氧化酶活性和机体抗氧化能力提高47.33%(P < 0.05),丙二醛含量降低37.05%(P < 0.05)。综上所述,母猪日粮中额外补充复合有机铁源能提高母猪繁殖性能,改善血液理化指标,增强母猪抗氧化能力。