利用高通量测序对封存CO2泄漏情景下土壤细菌的研究

全球CO2浓度不断升高的背景下,地质封存CO2为控制大气CO2浓度上升提供了全新的思路,但封存CO2潜在的泄漏风险也对生态系统产生重大威胁.土壤微生物与土壤健康密切联系.鉴于目前地质封存CO2泄漏对土壤微生物影响的研究鲜有报道,本研究通过模拟地质封存CO2泄漏情景,利用Miseq平台Illumina第二代高通量测序土壤细菌16S rRNA基因,结合相关生物信息学分析,初步探讨了封存CO2泄漏情景下农田土壤细菌群落丰富度、多样性和群落结构的变化.试验共获得15个土壤样本的43 017个OTU共486 645条读数,生物学分析结果表明,封存CO2泄漏通量和时间不同的情景下,农田土壤细菌丰富度和细菌群落多样性的变化存在差异,初步推测CO2泄漏量增大和泄漏时间持续更长的情景下,土壤细菌丰富度和多样性下降幅度较大,土壤细菌群落中优势菌群向若干细菌集中,其中土壤酸杆菌门细菌相对增多可能作为地质封存CO2泄漏对土壤生态系统影响的生物监测指标.     

CO2倍增和施氮对水稻不同生长期土壤反硝化细菌丰度的影响

随着全球气候变化的不断加剧,大气CO₂浓度呈明显增加趋势,这将间接影响土壤-植物-微生物系统的氮循环过程.为研究典型水稻土壤反硝化细菌对CO₂浓度升高的响应规律和机制,借助水稻密闭培养箱,运用实时荧光定量聚合酶链式反应（Real-Time qPCR）分子技术,设置不施氮（0 mg/kg）和常规施氮（100 mg/kg）2个处理,研究CO₂倍增对水稻不同生长期土壤关键反硝化功能细菌（narG、nirK和nirS型）丰度的影响.结果表明:①在2种施氮水平,CO₂倍增显著促进了水稻分蘖期、孕穗期、扬花期和成熟期水稻根系生长（增幅为2.96%~28.4%）、地上部生物量增加（增幅为7.1%~107.3%）以及成熟期籽粒干质量的增加（增幅为19.5%和38.0%）,具有显著的增产效应.②反硝化细菌丰度对CO₂倍增的响应与生育期及施氮水平有关,CO₂倍增在2个施氮水平均抑制分蘖期反硝化细菌的繁殖,显著增加孕穗期反硝化细菌数量;在水稻扬花期,CO₂倍增促进了施氮处理narG和nirS型反硝化细菌数量的增加,在成熟期抑制未施氮处理下narG、nirK和nirS型反硝化细菌的生长.另外,narG、nirK、nirS型反硝化细菌丰度整体表现为narG > nirS > nirK,且随水稻的生长,其在成熟期的丰度均呈降低趋势.nirK和nirS基因同属亚硝酸还原酶,但nirS基因丰度高于nirK,且对CO₂倍增和施氮的响应有所差异.研究显示,CO₂倍增可显著增加水稻生长和产量,不同施氮水平对稻田土壤反硝化细菌丰度的影响存在差异.      

土壤质地对自养固碳微生物及其同化碳的影响

自养微生物可同化大气中的CO2并将其转化为土壤有机碳,对提高农田土壤的碳吸收和碳储存有重要意义,然而土壤质地对自养固碳微生物功能种群及其同化碳的影响机制还不清楚.本研究选取亚热带地区同一母质发育而成的两种质地水稻土壤(壤质黏土和砂质黏壤土),通过14C-CO2连续标记技术结合室内模拟培养实验,探讨土壤质地对自养微生物同化碳(14C-SOC)、自养微生物截留碳(14C-MBC)和自养微生物可溶性碳(14C-DOC)的影响.以固碳功能基因(cbb L基因)作为指示基因,结合PCR和克隆测序技术,分析不同质地土壤自养固碳微生物群落结构和多样性的差异.结果表明,壤质黏土14C-SOC、14C-MBC和14C-DOC平均含量分别为133.81、40.16和8.10 mg·kg-1,均显著高于砂质黏壤土14C-SOC(104.95 mg·kg-1)、14C-MBC(33.26 mg·kg-1)和14C-DOC(4.18 mg·kg-1)平均含量(P0.05),说明土壤质地显著影响了土壤自养微生物碳同化量以及自养微生物同化碳在土壤中的转化.稀疏曲线、细菌cbb L基因文库覆盖度以及多样性指数分析结果显示壤质黏土固碳细菌群落多样性高于砂质黏壤土.系统发育分析表明,壤质黏土细菌cbb L基因序列与Rhodoblastus acidophilus、Blastochloris viridis、Thauera humireducens、Mehylibium sp.、Variovorax sp.等具有一定的同源性,而砂质黏壤土cbb L基因序列主要与根瘤菌和放线菌同源.可见,土壤质地对自养固碳微生物群落结构和多样性产生了深刻的影响,壤质黏土中较高的黏粒含量、土壤养分含量和阳离子交换量可能有利于维持更高的自养固碳微生物多样性和活性,从而导致不同质地土壤自养微生物碳同化量及其转化存在显著差异.     

不同生态系统土壤生化特征及其与土壤呼吸和N2O排放的关系

通过室内培养实验,研究了不同生态系统土壤生化特征及其对土壤呼吸和N2O排放的影响.结果表明,不同生态系统土壤的生化特征不同,土壤呼吸和N2O排放也不相同.一般果园细菌数量最多,草地放线菌数量最多,林地真菌数量最多,而竹园细菌放线菌数量最少,果园真菌最少;微生物碳氮含量一般果园>林地>农田.相关分析表明细菌数量与微生物碳氮呈显著正相关,放线菌数量与土壤有机碳和全氮含量呈极显著正相关(P<0.01),而真菌数量仅与全氮含量呈显著正相关(P<0.05).土壤呼吸累积排放量从高到低为果园>竹林>农田>林地>草地.N2O累积排放量为农田>果园>草地>林地>竹林.土壤呼吸与细菌、微生物碳氮呈显著正相关(P<0.05);土壤的N2O排放与三大微生物、铵态氮呈显著正相关(P<0.05).逐步回归分析表明土壤呼吸主要取决于土壤细菌数量和pH的变化;土壤N2O排放主要取决于土壤细菌数量和铵态氮含量的变化.     

贵州喀斯特水库红枫湖、百花湖P(CO2)季节变化研究

针对贵州喀斯特地区富营养水库（红枫湖、百花湖）表层水中的CO₂分压P(CO₂)进行为期1 a的监测,分析了影响两湖P(CO₂)季节变化的因素并阐明了两湖P(CO₂)季节变化的机理.不同于北部温带地区水库,两湖出现明显的季节变化特征：夏季表层水中CO₂欠饱和,其他季节CO₂过饱和.通过对物理、化学及生物因素与P(CO₂)之间的相关性分析. 结果表明,两湖P(CO₂)与Chla之间存在的显著负相关,是由于浮游植物光合作用与细菌呼吸作用共同影响的结果,也是两湖P(CO₂)出现季节变化的主要原因.水温与P(CO₂)之间的显著负相关,主要是由于水温影响浮游植物生长引起的.降雨量与P(CO₂)之间的显著负相关,主要是由于降雨量影响水库中营养盐的输入和浮游植物生长引起的.NO^-₃、NO^-₂与P(CO₂)之间的显著正相关,是藻类吸收与有机质降解、硝化反应等共同作用的结果.SiO^{2-₃与P(CO₂)之间的显著负相关,是SiO2-₃受降雨输入及藻类吸收共同影响的结果.而两湖DOC与P(CO₂)相关性的差异可能与两湖DOC来源不同有关.}     

Anaerobic biodegradation of PAHs in mangrove sediment with amendment of NaHCO3

Mangrove sediment is unique in chemical and biological properties. Many of them suffer polycyclic aromatic hydrocarbon(PAH) contamination. However, the study on PAH biological remediation for mangrove sediment is deficient. Enriched PAH-degrading microbial consortium and electron acceptor amendment are considered as two effective measures. Compared to other electron acceptors, the study on CO2, which is used by methanogens, is still seldom. This study investigated the effect of Na HCO3 amendment on the anaerobic biodegradation of four mixed PAHs, namely fluorene(Fl), phenanthrene(Phe),fluoranthene(Flua) and pyrene(Pyr), with or without enriched PAH-degrading microbial consortium in mangrove sediment slurry. The trends of various parameters, including PAH concentrations, microbial population size, electron-transport system activities, electron acceptor and anaerobic gas production were monitored. The results revealed that the inoculation of enriched PAH-degrading consortium had a significant effect with half lives shortened by 7–13 days for 3-ring PAHs and 11–24 days for 4-ring PAHs. While Na HCO3 amendment did not have a significant effect on the biodegradation of PAHs and other parameters, except that CO2 gas in the headspace of experimental flasks was increased.One of the possible reasons is that mangrove sediment contains high concentrations of other electron acceptors which are easier to be utilized by anaerobic bacteria, the other one is that the anaerobes in mangrove sediment can produce enough CO2 gas even without adding Na HCO3.     

炉渣与生物炭施加对稻田温室气体排放及其相关微生物影响

为了减少稻田温室气体排放通量,本研究对稻田土壤进行炉渣和生物炭单一施加和混合施加处理,并测定了早、晚稻拔节期和乳熟期CO_2、CH_4和N_2O排放通量及相关微生物(细菌、真菌、硝化细菌、反硝化细菌)的数量.结果表明,稻田施加废弃物可以减少温室气体的排放通量.在早、晚稻的拔节期,施加生物炭显著降低了CO_2和N_2O的排放通量(p0.05),混合施加显著降低了CO_2和CH_4的排放通量(p0.05),施加炉渣条件下3种温室气体的排放通量与对照组相比没有差异.施加炉渣或生物炭都显著降低硝化细菌的数量(p0.05),混施处理显著降低细菌、硝化细菌、反硝化细菌数量(p0.05),但显著提高了稻田土壤真菌/细菌比值(p0.05).在早、晚稻的乳熟期,炉渣、生物炭、混施处理能显著降低CH_4排放通量(p0.05),而生物炭处理显著降低N_2O排放通量(p0.05).炉渣处理显著降低细菌、硝化细菌、反硝化细菌数量(p0.05),生物炭处理显著降低细菌、反硝化细菌数量(p0.05),混施处理显著降低细菌、硝化细菌数量,并显著提高真菌/细菌比值(p0.05).温室气体排放与微生物数量之间的相关性分析结果表明,CO_2、CH_4排放通量与细菌数量呈显著正相关,与真菌/细菌比值呈显著负相关;而N_2O排放通量则与硝化细菌、反硝化细菌数量呈显著正相关.     

混合电子供体对好氧非光合微生物菌群固碳效率影响的析因实验分析

通过混合电子供体析因实验,定量描述了Na2S、NaNO2、Na2S2O3 3种无机物的用量和比例与非光合微生物固碳量之间的关系,并分析了3种电子供体之间的两两交互作用.最后,通过16S rDNA V3区DGGE图谱分析,研究了不同混合电子供体对固碳微生物群落结构的影响.结果表明,电子供体析因实验的模型具有较好的拟合度,...     

土壤硝化和反硝化微生物群落及活性对大气CO2浓度和温度升高的响应

硝化和反硝化微生物参与土壤氮循环转化过程,大气CO_2浓度和温度升高可能会影响它们的群落结构和活性.本试验依托稻-麦轮作农田系统气候变化平台研究大气CO_2浓度单独升高(CE)、升温(WA)以及两者同时升高(CW)对麦田土壤硝化和反硝化微生物基因丰度、群落结构和活性的影响.结果表明,在小麦分蘖期,大气CO_2浓度和温度升高对氨氧化细菌(AOB)和反硝化细菌丰度没有影响,而在抽穗和成熟期,CO_2浓度单独升高显著提高了氨氧化古菌(AOA)和反硝化细菌丰度,升温处理对其没有显著影响.通过对T-RFLP数据分析发现,大气CO_2浓度和温度升高对土壤AOA、AOB和反硝化细菌群落结构没有显著影响,但是在一定程度上改变了AOA和反硝化细菌多样性.另外,CO_2浓度单独升高处理显著提高了成熟期的土壤硝化速率,不同气候变化处理对反硝化速率没有显著影响.研究表明大气CO_2浓度和温度升高对不同生育期的微生物群落影响存在差异,而且功能微生物对不同气候变化因子处理的响应也各不相同.     

Universally improving effect of mixed electron donors on the CO2 fixing efficiency of nonphotosynthetic microbial communities from marine environments

The universality of improved CO2 fixing upon the addition of mixed electron donors（MEDs）composed of Na2 S,NO2-,and S2O32-to non-photosynthetic microbial communities（NPMCs）obtained from 12 locations in four oceans of the world was validated. The CO2 fixing efficiencies of NPMCs were universally enhanced by MED compared with those obtained using H2 alone as electron donor,with average increase of about 276%. An increase in microbial inoculation concentration could increase the net amount of CO2 fixing to853.34 mg/L in the presence of MED. NO2-and S2O32-may play the roles of both electron acceptor and electron donor under aerobic conditions,which may improve the energy utilization efficiency of NPMC and enhance the CO2 fixation efficiency. The sequence determination of 16 S ribosomal deoxyribonucleic acid（rDNA） from 150 bacteria of NPMC showed that more than 50% of the bacteria were symbiotic and there were many heterotrophic bacteria such as Vibrio natriegens. These results indicate that NPMC acts as a symbiotic CO2 fixing system. The interaction between autotrophic and heterotrophic bacteria may be a crucial factor supporting ladder utilization and recycling of energy/carbon source.     

Tradable CO2 permits for cars and trucks

The accelerated diffusion of cleaner vehicles to reduce CO₂ emissions in transport can be explicitly integrated in emission trading designs by making use of cross-sectoral energy efficiency investment opportunities that are found in data on CO₂ emissions during the production and the use of cars and trucks. We therefore elaborate the introduction of tradable certificates that are allocated or grandfathered to manufacturers that provide vehicles (and other durable goods) that enable their customers to reduce their own CO₂ emissions. This certificate is an allowance for each tonne CO₂ avoided. Manufacturers can then sell these certificates on the emission market and use the revenues to lower the price of their cleanest vehicles. This mechanism should partially overcome the price difference with less efficient cars. In a simulation, we found that the introduction of the certificate in tradable permit systems can lead to very significant reductions of CO₂ emissions. The simulations indicate that CO₂ emissions resulting from the car fleet can be reduced by 25–38% over a period of 15 years (starting in 1999). For the truck fleet, the reduction potential is more limited but still very interesting.     

CO2封存泄漏的稻田土壤细菌监测指标筛选研究

为研究CO₂地质封存过程中CO₂泄漏对水稻及稻田土壤的风险影响,利用CO₂模拟泄漏平台,研究了不同CO₂泄漏速率下水稻生长、稻田土壤性质与土壤细菌组成及多样性的变化特征.结果表明：随着CO₂泄漏速率的增加,稻田土壤pH显著降低,电导率显著增加,水稻生长受到明显抑制;稻田土壤细菌的丰富度指数和多样性指数均有增加,均匀度指数有所降低.CO₂泄漏显著改变了稻田土壤细菌组成,稻田土壤的优势菌门中变形菌门、拟杆菌门与绿弯菌门的相对丰度总体降低,而酸杆菌门与放线菌门的相对丰度总体升高;稻田土壤优势菌属中RB41、MND1、厌氧粘菌属及鞘脂单胞菌属的丰度总体升高,而硝化螺旋菌属的丰度总体降低;稀有细菌中CO₂泄漏下全部出现的有粘胶球形菌门、柔膜菌门及双头菌属、硫杆菌属,CO₂泄漏后全部消亡的为假单胞菌属.建议将变形菌门的减少和酸杆菌门的增加,以及RB41、MND1及厌氧粘菌属的增加作为稻田土壤CO₂泄漏监测的推荐指标.     

A new method for assessing CO2-emissions from container terminals: a promising approach applied in Rotterdam

At present, the notion is generally accepted that societies have to combat climate change. The reduction of CO₂-emissions, an important cause for global warming, has become a priority, and consequently there is increasing pressure on governments and industries to come forward with initiatives to reduce CO₂-emissions. This is highly relevant for the transport sector, as the share of transportation is still increasing, while other sectors are reducing their CO₂-footprint. The main purpose of this paper is to present a methodology to analyse the CO₂-emissions from container terminals, illustrated by the Port of Rotterdam.The objective of this paper is twofold. Firstly, the development of a methodology to analyse and gain a better understanding of the CO₂-emissions by container terminals in port areas is described. Secondly, the most effective solutions to reduce CO₂-emissions by container terminals in port areas are identified. The study provides insight into the processes of container transshipment at the terminals and the contribution of these processes to the CO₂-emissions of the container terminals. Using these insights, potential solutions to reduce the CO₂ at the terminals are identified and policy proposals are made for the operators of existing terminals and for governments.The most effective measure for CO₂ reduction is undoubtedly the adaptation of the terminal layout as in the example of the Rotterdam Shortsea Terminal. This makes it possible to reduce the CO₂-emissions of the current terminals by nearly 70 per cent. The other perspective is the incorporation of mixing 30 per cent biofuels with the presently used diesel. This results in a reduction of CO₂-emissions by between 13 and 26 per cent per terminal and a reduction of the emissions of the total container sector by 21 per cent. On the basis of these findings, concrete recommendations are made to reducing CO₂-emissions at container terminals.     

Strategies for improving the photocatalytic performance of metal-organic frameworks for CO2 reduction: A review

Photocatalytic CO₂ reduction is an appealing strategy for mitigating the environmental effects of greenhouse gases while simultaneously producing valuable carbon-neutral fuels. Numerous attempts have been made to produce effective and efficient photocatalysts for CO₂ reduction. In contrast, the selection of competitive catalysts continues to be a substantial hindrance and a considerable difficulty in the development of photocatalytic CO₂ reduction. It is vital to emphasize different techniques for building effective photocatalysts to improve CO₂ reduction performance in order to achieve a long-term sustainability. Metal-organic frameworks (MOFs) are recently emerging as a new type of photocatalysts for CO₂ reduction due to their excellent CO₂ adsorption capability and unique structural characteristics. This review examines the most recent breakthroughs in various techniques for modifying MOFs in order to improve their efficiency of photocatalytic CO₂ reduction. The advantages of MOFs using as photocatalysts are summarized, followed by different methods for enhancing their effectiveness for photocatalytic CO₂ reduction via partial ion exchange of metal clusters, design of bimetal clusters, the modification of organic linkers, and the embedding of metal complexes. For integrating MOFs with semiconductors, metallic nanoparticles (NPs), and other materials, a number of different approaches have been also reviewed. The final section of this review discusses the existing challenges and future prospects of MOFs as photocatalysts for CO₂ reduction. Hopefully, this review can stimulate intensive research on the rational design and development of more effective MOF-based photocatalysts for visible-light driven CO₂ conversion.     

不同源汇信息提取方法对区域CO2源汇估算及其季节变化的影响评估

从大气二氧化碳(CO2)浓度观测资料中准确提取源汇或本底信息对区域及全球碳源汇及大气CO2浓度长期变化趋势的定量估计至关重要.本研究以瓦里关大气CO2浓度观测资料为例,探讨了同期地面风和同期一氧化碳(CO)浓度观测资料作为源汇信息提取或本底值筛选因子的有效性.结果表明,地面风和同期CO浓度在冬季可作为筛选因子,但是夏季将其作为筛选因子不是十分有效.采用局部近似回归法(robust estimation of background signal,REBS)、傅里叶变换法(Fourier transform algorithm,FTA)和新发展的平均移动过滤法(moving average filtering,MAF)进行大气CO2浓度源汇及本底信息提取.结果表明,MAF法因其以每2周为一个拟合窗口,采用不断变化和调整的过滤标准,避免了在局部将抬升浓度或吸收浓度百分比过高或者过低估计,优于另外两种方法.3种方法对因区域排放源导致的大气CO2的抬升量的结果无显著差异,但对因区域吸收汇导致的大气CO2降低量差异明显.结果表明,3种方法均可以对受到人类活动排放源影响的CO2抬升浓度合理地筛分,但只有MAF法可对夏季吸收浓度较好地判别.MAF法获得的1995~2008年瓦里关大气CO2多年平均季振幅为约10.3×10-6(摩尔分数,下同),与前期观测结果一致;而REBS法得到的大气CO2逐年季振幅约为9.1×10-6,将会导致低估区域或全球CO2通量值.     

The adequacy of GWPs as indicators of damage costsincurred by global warming

This article looks at the ability of Global Warming Potentials (GWPs) towork as indicators of equivalence for temperature development and damagecosts. We look at two abatement scenarios that are equivalent when using100-year GWPs: one scenario reduces short-lived gases, mainly methane(CH₄); the other scenario reduces carbon dioxide (CO₂).Despite their equivalence in terms of CO₂ equivalents, the scenariosdo not result in equal rates or levels of temperature change. The disparitiescontinue as we move further down the chain of causality toward damagecosts, measured either in terms of rate of climate change or level of climatechange. Compared to the CH₄ mitigation scenario, the CO₂mitigation scenario gives present value costs 1.3 and 1.5 times higher forlevel- and rate-dependent damage costs, respectively, assuming a discountrate of 3%. We also test the GWPs for other time horizons and theconclusions remain the same; using GWP as an index to reflect equivalentclimate effects and damage costs from emissions is questionable.     

CO2-咸水-砂岩相互作用过程中微生物群落结构动态变化特征

采用MiSeq高通量测序技术,分析CO_2-咸水-砂岩相互作用过程中微生物群落结构及多样性的动态变化特征.结果表明CO_2注入咸水层后,部分微生物可在极端条件(高温、酸性)下生长.在CO_2-咸水-砂岩相互作用过程中,微生物菌属种类趋于单一,变形菌门相对丰度最终达到99.77%.优势菌属在群落结构变化过程依次为假单胞菌属,柠檬酸杆菌属及短波单胞菌属.同时,CO_2注入后还存在着芽孢杆菌属,嗜氢菌属,根瘤菌属等微生物群落结构变化过程中特有的微生物菌群;随着CO_2注入时间的延长,香农指数逐渐变小,辛普森指数逐渐变大,表明微生物群落结构变化过程中,细菌多样性显著降低,且变化过程中所发现的芽孢杆菌属、柠檬酸杆菌属、假单胞菌属等菌属均能够促进CO_2在微生物介导的CO_2-咸水-砂岩相互作用过程中的溶解/沉淀捕获.此外,注入CO_2后香农指数从5.330 2降至1.946 5,表明生物多样性显著减少.研究发现,以上几类菌属对钾、钠长石类矿物以及绿泥石的溶蚀有着积极的作用,同时也促进了方解石、菱铁矿等矿物的生成.反之,CO_2-咸水-砂岩相互作用过程中矿物溶解或沉淀过程导致的pH的变化,水化学组分中的阴阳离子浓度的变化等,与微生物群落结构变化存在着密切的关系.     

模拟酸雨对福州平原水稻田温室气体排放的影响

农田生态系统是温室气体的重要排放源,研究酸雨对水稻田温室气体排放及其综合增温潜势的影响,对我国酸雨背景下农田生态系统固碳减排具有重要的现实意义.本文以福州平原水稻田为研究区,通过模拟酸雨探讨其对水稻田CO_2、CH_4和N_2O排放通量及其综合增温潜势的影响.结果表明:模拟酸雨并未显著改变早、晚稻田CO_2、CH_4和N_2O排放的季节变化规律,但降低了其排放通量.与对照组相比,pH=4.5酸雨作用下,早稻田CO_2、CH_4和N_2O平均排放通量依次降低11.54%、133.33%和22.22%,晚稻田CO_2和N_2O平均排放通量依次降低39.53%、156.00%,而CH_4平均排放通量与对照组差异不显著;pH=3.5酸雨作用下,早稻田CO_2、CH_4和N_2O平均排放通量分别降低10.82%、75.00%、54.00%,晚稻田平均排放通量分别降低17.32%、20.00%和197.67%.综合增温潜势表明,CO_2的增温潜势显著高于CH_4和N_2O,是稻田生态系统中温室效应的主要温室气体,在pH=4.5和pH=3.5的酸雨作用下,早、晚稻田生态系统温室气体综合增温潜势均降低.     

一种能同时固定CO2和N2的微生物——兼性固CO2、N2菌的分离鉴定及其验证实验

"温室效应"日趋严重,生物固碳特别是微生物固碳将发挥独特的作用.固定N2的微生物固氮菌和固定CO2的微生物固碳菌早已被研究和发现,但能同时固定大气中的CO2、N2并以CO2、N2分别为碳、氮源的微生物至今未见报道,本研究称之为兼性固CO2、N2菌.研究通过固碳菌、固氮菌培养基的优化组合出无碳、氮培养基(分别以空中的CO2、N2为碳源和氮源);通过无氮碳源的兼性固碳氮菌培养基进行分离,筛选分离到一株分别以CO2和N2为碳源和氮源.通过对该菌株的生长特性和固碳酶活性及固氮酶活性进行测定;利用PCR和琼脂糖凝胶电泳技术检测到该菌含有固碳酶RubisCO中cbbL基因及固氮酶nifH基因片段的特异性条带;对该菌进行对照验证实验证明该菌能同时固定空气中的CO2和N2并分别以CO2和N2为碳源和氮源;最后对其形态观察和16SrRNA全序列分析证明该菌株HSJ隶属于链霉菌.     

菌渣-发酵床废弃垫料堆肥中温室气体排放及与微生物的关系

堆肥是处理农业废弃物最适宜的技术之一,但堆肥产生的有害和温室气体排放导致环境污染问题.本研究以生猪养殖发酵床废弃垫料及菌渣为原料,利用强制通风静态堆肥技术研究垫料和菌渣不同配比及添加EM菌剂对堆肥过程温室气体排放和微生物区系的影响.结果表明,不同堆肥处理温室气体排放通量以堆肥前20 d较大,堆肥中后期降低;微生物总量和种类在不同堆肥处理间没有发生显著性变化;CO_2和N_2O排放速率与细菌、真菌和甲烷氧化菌间具有显著的正相关关系.整个堆肥期间,以菌渣为主料并添加EM菌剂的堆肥处理温室气体减排效果最佳,相对其他3个处理温室气体减排0.7%~10.2%.由此认为,以菌渣为主料和通过添加EM菌剂的堆肥方式可以作为降低菌渣-发酵床废弃垫料堆肥过程温室气体排放的策略.