Treatment of cow-waste slurry by a microbial fuel cell and the properties of the treated slurry as a liquid manure

Resource recycling and the proper treatment of animal waste to reduce its environmental impact are currently important issues for the livestock industry. A microbial fuel cell (MFC), a new type of bioreactor, is expected to play roles in both waste‐water purification and energy recovery. However, the generation of electricity from cow waste has not yet been examined. In this study, using an MFC, we examined the possibility of generating electricity from dairy‐cow waste slurry, and analyzed the properties of the treated slurry as liquid manure for resource recycling. The MFC treatment of the slurry generated electricity in a dose‐dependent manner, and the maximum power output by the MFC from a 1 g of chemical oxygen demand/L slurry was 0.34 mW/m². After the MFC treatment, 84% of the biological oxygen demand in the slurry was removed and three essential fertilizer elements (nitrogen, phosphorus, and potassium) were retained at 84, 70, and 91% levels, respectively. The amount of ammonia nitrogen in the slurry, as an element of fast‐release fertilizer, was increased by 1.9‐fold. Although the treated slurry displayed properties that made it preferable as liquid manure, further studies to improve the electrical power output by the MFC are required for practical use.     

微生物除草剂与生物安全

随着人类环境意识的提高和农业可持续发展的需要,高效、环保微生物除草剂的研究越来越显示其重要的社会意义和经济价值。本文概述了微生物除草剂的种类、剂型及特点,介绍了利用微生物及其天然产物防治杂草的潜在优势和目前国内外的研究进展,尤其是对微生物除草剂的生物安全性进行了评价。     

人工感染柔嫩艾美耳球虫对雏鸡盲肠正常菌群的影响

在对雏鸡人工感染柔嫩艾美耳球虫后6、8、13、20天,分别对感染雏与未感染雏盲肠内容物中梭杆菌、真杆菌、消化球菌、乳酸杆菌、类杆菌、肠球菌、葡萄球菌和肠杆菌等8种主要正常菌群进行定性、定量分析。结果发现在球虫感染第20天,感染组有益菌如乳酸杆菌的数量低于对照组,差异极显著(P<0.01),有害菌如梭杆菌、葡萄球菌数量感染组高于对照组,其中梭杆菌差异显著(P<0.05),葡萄球菌差异极显著(P<0.01)。     

浑善达克沙地药用种子植物区系分析

本文应用植物区系地理学的基本原理,对浑善达克沙地药用种子植物的科、属组成和属的地理成分进行了统计分析,结果表明:(1)本区有药用种子植物78科,270属,504种。(2)优势科现象明显;单种属、寡种属数量最多,属级水平的多样性丰富。(3)该区系包含14个分布区类型,温带性质的成分占绝对优势,热带性质的成分不多,特有程度低。(4)资源区域间分布差异大;有一定的古老成分。     

景谷县植物多样性调查

在分析景谷县的有关植物研究基础后，记载了景谷县森林植被，国家珍稀濒危保护植物，统计了全县植物种类数量，在此基础上分析了主要经济植物资源，并讨论了确定了景谷县森林植物区系敏感区的原则，根据其原则确定景谷县威远江流域、小黑江流域等７个地区为景谷县森林植物区系敏感区。     

微生物肥料促进红松幼苗生长的研究

微生物肥料采用多项国际国内领先技术研制、生产,具有高效、环保等特点。应用微生物肥料进行林业育苗可促进苗木的生长,为天然林保护工程和退耕还林还草工程提供高质量的幼苗。本文对微生物肥料培育林业建设苗木进行了研究,试验结果表明,微生物肥料促进红松生长,施用微生物肥料的红松,其株高、地径及生物量均有明显增长,可为林业建设提供优质苗木。     

基于Meta分析研究毛竹入侵致土壤pH提升及养分和微生物群落结构的变化

诸多研究发现毛竹入侵周围林分提高土壤pH，但未见统计性描述报道。为此，本研究将通过大数据分析证实此现象的普遍性以及探究伴随的土壤养分和微生物变化。本研究收录包含毛竹入侵有关土壤pH变化的42篇文献总计101组数据，采用整合分析方法（Meta-analysis）进行深入探讨。在研究土壤养分变化时，本文还结合了团队采集的12个毛竹入侵带的样地数据总计92个样品18组数据进行分析。结果表明，在所有的数据组中，84.9%的土壤在经过毛竹入侵后其pH有不同幅度的提升，说明毛竹入侵周围林分普遍提高土壤pH；土壤pH增加幅度随入侵阶段、毛竹纯林时间增加而增加，随土层深度增加而降低；入侵针叶林致土壤pH增加的幅度高于阔叶林。入侵的毛竹纯林与原生林相比，总体上显著降低（P<0.05）了土壤全氮（-15.9%）、硝态氮（-21.7%）、全碳（-2.0%），却增加（P<0.05）了土壤有效磷（+54.9%）、铵态氮（+14.7%）和碱解氮（+8.2%）。对27篇包含微生物数据的文献进行整合分析，结果表明毛竹入侵改变了微生物群落结构，增加（P<0.05）了放线菌门相对丰度（+25.86%），而降低（P<0.05）了酸杆菌门（-15.49%）、浮霉菌门（-26.66%）、拟杆菌门（-22.58%）的相对丰度。本研究通过Meta分析证明毛竹入侵周围林分提高土壤pH为普遍自然现象，结合土壤硝态氮和铵态氮指标的变化推测了导致土壤pH提升的可能机制，毛竹入侵提高了土壤细菌和真菌多样性，表明入侵对土壤微生物具有正反馈效应。     

Mineralization of “non‐metabolizable” glucose analogues in soil: potential chemosensory mimics of glucose

Glucose is widely used to study the dynamics of easily available organics in soil. Pure culture studies have revealed that many microorganisms can sense and respond to glucose through chemosensory mechanisms that are not directly reliant on energy catabolism. However, the rapid mineralization of glucose by microorganisms makes it difficult to disentangle its energy effects from such non‐catabolic interactions. “Non‐metabolizable” glucose analogues have proven useful in mechanistic studies of glucose in pure culture, but have never been applied to complex microbial communities in soil. We sought to determine how their mineralization in soil differs from that of glucose, and whether they have potential as a new approach for investigating chemosensory mechanisms in soil microbiology. We incubated soil from an agricultural Haplic Luvisol under controlled conditions for 24 d and monitored CO₂ efflux after addition of (1) glucose, and three “non‐metabolizable” glucose analogues: (2) 2‐deoxyglucose (DG), (3) α‐methylglucoside (αMG), and (4) 3‐O‐methyl‐glucose (OMG), at three concentration levels, along with a control. All three analogues did in fact produce a large increase in soil CO₂ efflux, but the dynamics of their mineralization differed from the rapid degradation seen for glucose. At medium and high concentrations, CO₂ efflux peaked between 2.5 and 4 d after amendment with DG and αMG, and was delayed by about one week for OMG. The markedly different patterns of mineralization between glucose and OMG offer a new tool for investigating the behavior of glucose in soil. By using OMG as a glucose model, chemosensory mechanisms could be studied with limited interference from energy catabolism.     

喀斯特地区泡核桃林土壤酶、微生物量及无机氮的动态研究

【目的】泡核桃林的土壤质地是决定核桃产量的重要因素。开展喀斯特地区泡核桃林土壤肥力状况及微生物群体功能年际变化的研究，不仅有助于指导泡核桃科学高效地生产，而且能为该地区的石漠化治理、土地修复实践提供理论基础。【方法】对喀斯特地区不同种植年限（4、5、6、7 年）泡核桃林土壤酶活性、微生物生物量（碳、氮）及无机氮（硝态氮、铵态氮）的变化及其相关性进行测定和分析。【结果】（1）泡核桃种植 5、6 年后，土壤酶活性普遍高于种植 4、7 年。（2）随着种植年限的增加，微生物量碳呈先增后降的趋势，而微生物量氮逐渐增加，且种植 5、6、7 年后差异不显著；泡核桃种植 4 年后的微生物量碳氮含量均极显著低于其他年限。（3）随着种植年限的增加，铵态氮含量呈波动式变化，硝态氮先增后减，且种植 6 年后的硝态氮含量极显著高于其他年限处理。（4）酶活性、微生物量和无机氮含量均随着土层深度（0~10、10~20、20~30 cm）的增加而降低，显示出明显的“表聚现象”。（5）酶活性、微生物量和无机氮含量三者之间具有不同程度的相关性。【结论】总体来看，泡核桃林的建立有利于喀斯特地区的土壤发育。在泡核桃种植 7 年后，应注重水肥管理以提升泡核桃果实的质量，同时为该区的生态恢复提供基础条件。