外包木霉内含芽孢杆菌颗粒生物有机肥研制及其促生效应

  目的  利用造粒喷涂技术,研制了外包木霉菌内含芽孢杆菌（SQR9）的颗粒复合菌生物有机肥,以辣椒为供试作物,利用盆栽试验,研究了新型生物有机肥对辣椒植株株高、茎粗、叶绿素等农艺性状的影响。  方法  首先利用圆盘造粒机将有机肥、芽孢杆菌和适量粘合剂制成颗粒芽孢杆菌生物有机肥,随后,再将真菌木霉孢子喷涂颗粒表面,利用第一次添加的粘结剂形成外包真菌孢子膜的新型颗粒复合菌生物有机肥。  结果  货架期试验结果表明,颗粒肥料中木霉菌比粉状肥料存活能力更强,在储存60天后,新型颗粒复合菌生物有机肥中木霉菌含量大于2 × 107 cfu g?1,芽孢杆菌数量大于1.2 × 108 cfu g?1。盆栽试验结果表明,在种植47天后,施用新型颗粒复合菌生物有机肥的辣椒植株在株高、茎粗、叶绿素、鲜重和干重方面均高于其他处理（含SQR9颗粒生物有机肥、含SQR9和木霉菌的粉状生物有机肥、含木霉菌颗粒生物有机肥和含SQR9和木霉菌的颗粒生物有机肥处理）,表明了该新型颗粒复合菌生物有机肥对辣椒具有明显的促生效果。  结论  相比于单菌和其他工艺研制的复合菌生物有机肥,外包木霉真菌内含芽孢杆菌新型颗粒复合菌生物有机肥能够充分发挥木霉真菌和芽孢杆菌的促生功能,有效增强复合菌生物有机肥的促生效果。     

地衣芽孢杆菌YC10发酵液对辣椒疫霉的抑制作用试验初报

测定了一株地衣芽孢杆菌YC10发酵液对辣椒疫霉菌的抑制率、菌丝的生长及游动孢子释放和萌发的影响。结果表明,地衣芽孢杆菌YC10发酵液对辣椒疫霉菌具有一定的抑制作用,抑制率达78.67%;可导致病原菌菌丝畸形、分支增多及原生质浓缩;对辣椒疫霉游动孢子释放和萌发的相对抑制率为36.91%和57.14%,与对照相比明显抑制了游动孢子的释放和萌发。     

土壤中细菌HC5的分离鉴定及抑菌活性测定

为了筛选出对马铃薯晚疫疫霉菌(Phytophthora infestans)有较强拮抗作用的生防细菌,从马铃薯种植地的土壤中分离细菌,并通过平板对峙法,测定分离细菌对马铃薯晚疫疫霉菌的拮抗作用。经大量拮抗实验,筛选出一株细菌HC5,经形态特征观察、生理生化特性测定和16S rRNA基因序列分析,确定该菌株为假单胞菌(Pseudomonas sp.)。抑菌试验结果表明,HC5菌株对辣椒疫霉菌(Phytophthora capsici)、黄瓜尖孢镰刀菌(Fusarium oxysporum)、马铃薯晚疫疫霉菌、辣椒炭疽菌(Colletotrichum capsici)均有一定的抑制作用,尤其对马铃薯晚疫疫霉菌的抑菌效果显著,抑菌率达89%。采用PCR方法对菌株HC5进行多种抗生素合成基因的检测,扩增到786 bp的硝吡咯菌素片段和587 bp的氢氰酸片段,表明菌株HC5能够代谢产生这两种抗生素,单一或协同发挥拮抗作用。研究表明,菌株HC5是一株具有开发潜力的生防细菌。     

牛粪堆肥中高效菌株的筛选与应用效果

为了探索牛粪快速腐熟原理及方法,以糖、淀粉、蛋白质、纤维素、油脂培养基为筛选培养基,以菌株增殖倍数、菌株性能等为筛选条件,从牛粪常温堆肥中筛选不同原料高效功能菌,并组成功能菌剂;以不同原料菌及单菌株发酵试验对发酵机制进行研究。结果表明,芽孢杆菌、假单胞菌、木霉及曲霉等为重要功能菌,组成功能菌剂发酵升温快,进入高温期仅需4 d,发酵腐熟时间可缩短至19~20 d;发酵及升温效果依次为糖原料功能菌淀粉原料功能菌蛋白质原料功能菌纤维素原料功能菌;芽孢杆菌、假单胞菌、木霉、曲霉利用糖、淀粉、蛋白质及纤维素能力强,升温及腐熟效果好。各菌株充分利用基质各成分,紧密协同生长及代谢,迅速进入高温期,是堆肥快速发酵及腐熟的主要作用机制。     

结晶纤维素降解细菌的筛选、分离与鉴定

采用以结晶纤维素（Avicel）为唯一碳源的平板活性筛选法,从60份森林腐殖土、腐术样品中分离得到2株在pH5．0、37℃条件下高效降解结晶纤维素的细菌菌株GXN152和GXN153。以菌株的总DNA基因为模板,用细菌的16S rRNA基因的通用引物扩增得到菌株GXN152和GXN153的16S rRNA基因序列。测序分析表明菌株GXN152的16S rRNA基因序列和洋葱假单胞菌（Burkholderia cepacia）菌株CNR22的16S rRNA基因序列的同源性最高,具有98％的同源性,生理生化特性检测表明菌株GXN152具有洋葱假单胞菌的鉴别特征,将结晶纤维素降解菌GXN152鉴定为洋葱假单胞菌。菌株GXN153的16S rRNA基因序列和类芽孢杆菌（Paenibacillus favisporus）菌株GMP01的16S rRNA基因序列的同源性最高,具有99％的同源性,生理生化特性检测表明菌株GXN153具有类芽孢杆菌的鉴别特征,将纤维素降解菌GXN153鉴定为类芽孢杆菌。     

氮离子注入诱变选育大豆疫霉高效拮抗菌

为获得生防效果更佳的芽孢杆菌和荧光假单胞菌菌株,本试验采用低能N+离子注入技术对DDGJ05、DDGJ01和DDEN01菌株进行诱变,并结合平板对峙培养法对N+离子注入诱变后的菌株进行筛选。结果表明,只有DDGJ05有正突变菌株的出现,正突变菌株的编号分别为DDGJ05-20-8、DDGJ05-40-8、DDGJ05-40-10。平板对峙培养试验结果表明,DDGJ05-20-8、DDGJ05-40-8、DDGJ05-40-10对大豆疫霉菌丝生长的抑制率分别为91.12%、93.52%和94.00%,均高于对照亲本菌株DDGJ05。继代培养试验结果表明,正突变菌株DDGJ05-40-8和DDGJ05-40-10对大豆疫霉的拮抗作用能够稳定遗传。采用盆栽法研究了DDGJ05和3个正突变菌株对大豆疫病的控制效果,结果表明,大豆种子经DDGJ05菌株及其3个正突变菌株处理后,对大豆疫病均有一定的防治效果,其发病严重程度均低于空白对照组,其中,经DDGJ05-40-10处理的防治效果最好,防治效果为63.43%。本研究结果为芽孢杆菌离子束注入诱变育种方法的研究提供了理论支撑。     

多粘类芽孢杆菌LRS-1对辣椒疫霉病害根际土壤细菌多样性的影响

【目的】研究多粘类芽孢杆菌LRS-1生防菌对患疫霉病的辣椒根际土壤细菌多样性的影响。【方法】通过对无病阴性对照(CK)、辣椒疫霉菌阳性处理(PC)和生防菌+辣椒疫霉菌处理(LRS1) 3个处理的盆栽根际土壤样品16S r RNA基因的V3-V4区进行高通量测序,并对下机数据予以相关生物信息学分析,获得了不同处理根际土壤细菌的OTU丰度、Alpha多样性、OTUs分布、群落组成差异以及PCA聚类分析等数据结果。【结果】各处理间的根际土壤细菌群落变化明显,疫霉菌处理明显降低了根际土壤细菌群落的丰富度和多样性,而接种多粘类芽孢杆菌LRS-1则可明显改善根际土壤细菌群落丰富度与多样性;接种LRS-1明显提高了辣椒根际土壤细菌种类组成的相似性,并改善疫霉菌胁迫下的细菌种类组成;各处理的优势物种类群均分布于变形菌门(Proteobacteria)、厚壁菌门(Firmicutes)、放线菌门(Actinobacteria),但疫霉胁迫条件下Sphingomonadaceae、Clostridiales物种丰度显著降低,而Burkholderiales、Micrococcales等物种丰度显著增加,接种LRS-1可改善此态势,且明显提高该生防菌所在的Paenibacillus物种比例。【结论】上述结果既证实了LRS-1在"疫霉-辣椒-LRS-1-根际土壤"复合体系下较好的定殖适应性,更体现了LRS-1对疫霉病态土壤根际细菌多样性具有明显的维持与修复作用。     

烟草黑胫病拮抗菌的筛选及其生物效应

烟草黑胫病是烟草生产中危害最严重的土传病害之一,生物防治具有抗病和环保的作用,获得高效拮抗菌株是进行生物防治研究的基础。本研究采用平板对峙法,在烟草黑胫病发生严重的田块中选取健康烟株,从其根际土壤中分离筛选到12株对烟草黑胫病病原菌Phytophthora parasitica var.nicotianae具有拮抗效果的菌株,抑菌率59.4%～71.1%。选择抑菌率最高的C-5菌株进行试验。经鉴定C-5菌株为多粘类芽孢杆菌(Paenibacillus polymyxa)。抗菌谱试验结果表明:C-5菌株不仅对黑胫病病原菌有较强的拮抗作用,同时对甜瓜?黄瓜枯萎病病原菌和辣椒疫病病原菌也具有拮抗作用。苗期盆栽试验结果表明:利用C-5菌株发酵制备的微生物有机肥能抑制烟草黑胫病的发生,苗期防治率达80%。本文首次报道了多粘类芽胞杆菌菌株对烟草疫霉有拮抗作用。     

木薯渣基质化发酵微生物分离及复合菌配制

为缩短木薯渣发酵周期，提升木薯渣基质产品质量，该研究以木薯渣为试验材料，对其自然发酵的4个关键时期微生物进行分离、鉴定，并探讨复合微生物菌对木薯渣的发酵效果。结果表明，从木薯渣发酵初始期、升温期、高温期和腐熟期，分别分离出30株、54株、25株和32株菌株。将分离出的菌株接种到刚果红培养基上，筛选出具有降解木质纤维素功能的菌株54株。采用16S rDNA与内转录间隔区ITS测序比对的方法，鉴定出与木薯渣发酵密切相关的微生物37株，其中细菌类主要以高地芽孢杆菌和地衣芽孢杆菌发酵效果最佳，放线菌类、真菌类分别以灰略红链霉菌、绿色木霉菌的效果较好。将上述菌株按比例复配形成微生物菌，发现3种微生物混合后的发酵效果最好，可使木薯渣纤维素质量分数降低到24.4%，且失重率显著高于商业菌剂。这些结果说明微生物之间通过相互协同作用，进一步促进木薯渣的发酵进程，其中以高地芽孢杆菌、地衣芽孢杆菌、灰略红链霉菌、绿色木霉菌复合发酵效果最好。     

瑞氏木霉碳源阻遏相关基因Cre1的分子改造

为了提高瑞氏木霉（Trichoderma reesei）纤维素酶的活力,用类似基因改组的方法改造其碳源阻遏相关基因cre1。以瑞氏木霉基因组DNA为模板PCR扩增cre1基因,用DNaseⅠ消化cre1基因后,回收50-100 bp的DNA片段,用T4 DNA连接酶连接,以连接产物作为模板进行无引物PCR,并将PCR产物转入瑞氏木霉原生质体,通过测定滤纸酶活的方法筛选突变菌株,并在NCBI上比对分析突变菌株的cre1基因。结果表明,筛选获得1株纤维素滤纸酶活比出发菌株提高0.7倍的突变菌株cre2-3。cre2-3菌株在液体培养基中呈棉花状,而出发菌株呈小颗粒状,菌株cre2-3发酵液的颜色比出发菌株的更黄亮。推测cre1基因与瑞氏木霉菌株的生长代谢有关。     

Soil application of insecticides influences microorganisms and plant nutrients

An experiment was conducted under laboratory conditions to investigate the effect of four insecticides, viz. HCH, phorate, carbofuran and fenvalerate at their field application rates (7.5, 1.5, 1.0 and 0.35 kg a.i. ha⁻¹, respectively), on the growth and development of bacteria, actinomycetes and fungi as well as their role in the transformations and availability of some plant nutrients in laterite soil (Typic Orchragualf). All the insecticides in general, and HCH and phorate in particular, significantly increased the population of microorganisms in soil. The most predominant genera of microorganisms, such as Bacillus, Micrococcus and Aspergillus were not affected by most of the insecticides. However, some of the insecticides stimulated the growth and development of Bacillus, Proteus, Corynebacterium, Streptomyces, Fusarium, Trichoderma and Rhizopus. On the other hand, some insecticide exerted deleterious effect on the proportions of Pseudomonas, Staphylococcus, Nocardia, Micromonospora, Aspergillus and Rhizopus. Incorporation of insecticides also significantly stimulated the mineralization and availability of organic C, N and P in soil. Among the tested substances, the stimulations were more pronounced with HCH followed by phorate and fenvalerate.     

两种退耕还林模式对土壤微生物优势类群的影响

以两种退耕还林模式的桦木林地、苦竹林地和农耕地(对照)为对象,对各样地土壤微生物优势类群数量的季节性动态变化、垂直分布特征及其与土壤酶活性的相关性进行了研究。结果表明,土壤微生物的优势类群为微球菌属(Micrococcus)、芽孢杆菌属(Bacillus)、链霉菌属(Streptomyces)、游动放线菌属(Actinoplanes)、酵母菌(未定属)、木霉菌属(Trichoderma)这6类。两种退耕还林模式下土壤优势微生物类群数量存在差异,春、夏、秋三季均为苦竹林所占比例最大,冬季为桦木林最大。两种林地和农耕地土壤微生物优势类群数量季节性变化规律为微球菌和酵母菌在夏、冬季较大,春、秋季较少;芽孢杆菌在秋季最大,夏季最小;游动放线菌与木霉菌数量在四季中变化不大;链霉菌是夏季最高,冬季最少。各优势微生物类群数量的垂直分布特征表现为微球菌、游动放线菌、木霉菌随土壤层的加深其数量逐渐降低,芽孢杆菌、链霉菌数量则随土壤层的加深而逐渐增加,酵母菌随土壤层的加深其数量减少,但趋势不明显。两种林地对各优势微生物类群数量的根际效应为:链霉菌和木霉菌的R/S值大于1,酵母菌的R/S值小于1,微球菌和游动放线菌在桦木林的R/S值大于1而在苦竹林小于1。在优势微生物类群和土壤酶之间,微球菌与转化酶,芽孢杆菌与纤维素酶,木霉和游动放线菌与过氧化氢酶,酵母与脲酶呈显著正相关关系。     

Diversity and antagonistic potential of Pseudomonas spp. associated to the rhizosphere of maize grown in a subtropical organic farm

Pseudomonas spp. are one of the most important bacteria inhabiting the rhizosphere of diverse crop plants and have been frequently reported as biological control agents (BCAs). In this work, the diversity and antagonistic potential of Pseudomonas spp. in the rhizosphere of maize cultivars Nitroflint and Nitrodent grown at an organic farm in Brazil was studied by means of culture-dependent and -independent methods, respectively. Sampling of rhizosphere soil took place at three different stages of plant development: 20, 40 and 106 days after sowing. A PCR-DGGE strategy was used to generate specific Pseudomonas spp. fingerprints of 16S rRNA genes amplified from total community rhizosphere DNA. Shifts in the relative abundance of dominant populations (i.e. PCR-DGGE ribotypes) along plant development were detected. A few PCR-DGGE ribotypes were shown to display cultivar-dependent relative abundance. No significant differences in diversity measures of DGGE fingerprints were observed for different maize cultivars and sampling times. The characterisation and assessment of the antagonistic potential of a group of 142 fluorescent Pseudomonas isolated from the rhizosphere of both maize cultivars were carried out. Isolates were phenotypically and genotypically characterised and screened for in vitro antagonism towards three phytopathogenic fungi and the phytopathogenic bacterium Ralstonia solanacearum. Anti-fungal activity was displayed by 13 fluorescent isolates while 40 isolates were antagonistic towards R. solanacearum. High genotypic and phenotypic diversity was estimated for antagonistic fluorescent Pseudomonas spp. PCR-DGGE ribotypes displayed by antagonists matched dominant ribotypes of Pseudomonas DGGE fingerprints, suggesting that antagonists may belong to major Pseudomonas populations in the maize rhizosphere. Antagonists differing in their genotypic and phenotypic characteristics shared the same DGGE electrophoretic mobility, indicating that an enormous genotypic and functional diversity might be hidden behind one single DGGE band. Cloning and sequencing was performed for a DGGE double-band which had no corresponding PCR-DGGE ribotypes among the antagonists. Sequences derived from this band were affiliated to Pseudomonas stutzeri and P. alcaligenes 16S rRNA gene sequences. As used in this study, the combination of culture-dependent and -independent methods has proven to be a powerful tool to relate functional and structural diversity of Pseudomonas spp. in the rhizosphere.     

Response of alfalfa (Medicago sativa L.) to single and mixed inoculation with phosphate-solubilizing bacteria and Sinorhizobium meliloti

The objectives of this work were to phenotypically and genetically characterize alfalfa rhizosphere bacteria and to evaluate the effect of single or mixed inoculation upon nodulation and biological nitrogen fixation. Thirty-two strains showed tricalcium phosphate solubilization ability, and two of them caused bigger or equal solubilization halos than the control strain P. putida SP22. The comparison of the 16S ribosomal DNA sequences indicated that these strains are phylogenetically related to Bacillus spp. and Pseudomonas spp. A beneficial effect of both isolates on alfalfa growth was observed in coinoculation assays. Pseudomonas sp. FM7d caused a significant increase in root and shoot dry weight, length, and surface area of roots, number, and symbiotic properties of alfalfa plants. The plants coinoculated with Sinorhizobium meliloti B399 and the Bacillus sp. M7c showed significant increases in the measured parameters. Our results indicating that strains Pseudomonas sp. FM7d and Bacillus sp. M7c can be considered for the formulation of new inoculants.     

Application of bio-organic fertilizer can control Fusarium wilt of cucumber plants by regulating microbial community of rhizosphere soil

Fusarium wilt, caused by Fusarium oxysporum f. sp. cucumerinum J. H. Owen, results in considerable yield losses for cucumber plants. A bio-organic fertilizer (BIO), which was a combination of manure composts with antagonistic microorganisms, and an organic fertilizer (OF) were evaluated for their efficiencies in controlling Fusarium wilt. Application of the BIO suppressed the disease incidence by 83% and reduced yield losses threefold compared with the application of OF. Analysis of microbial communities in rhizosphere soils by high-throughput pyrosequencing showed that more complex community structures were present in BIO than in OF treated soils. The dominant taxonomic phyla found in both samples were Proteobacteria, Firmicutes, Actinobacteria and Acidobacteria among bacteria and Ascomycota among fungi. Abundance of beneficial bacteria or fungi, such as Trichoderma, Hypoxylon, Tritirachium, Paenibacillus, Bacillus, Haliangium and Streptomyces, increased compared to the OF treatment, whereas the soil-borne pathogen, Fusarium, was markedly decreased. Overall, the results of this study demonstrate that the application of the BIO was a useful and effective approach to suppress Fusarium wilt and that the high-throughput 454 pyrosequencing was a suitable method for the characterization of microbial communities of rhizosphere soil of cucumber.     

Arsenic-contaminated soils genetically modified<Emphasis Type="Italic">Pseudomonas</Emphasis> spp. and their arsemc-phytoremediation potential

Sorghum was inoculated withPseudomonas bacteria, including strains harboring an As-resistance plasmid, pBS3031, to enhance As-extraction by the plants.Pseudomonas strains (P.fluorescens 38a, P.putida 53a, and P.aureofaciens BS1393) were chosen because they are antagonistic to a wide range of phyto-pathogenic fungi and bacteria, and they can stimulate plant growth. The resistance of natural rhizospheric pseudomonads to sodium arsenite was assessed. Genetically modifiedPseudomonas strains resistant to As(III)/As(V) were obtained via conjugation or transformation. The effects of the strains on the growth of sorghum on sodium-arsenite-containing soils were assessed. The conclusions from this study are: (1) It is possible to increase the survivability of sorghum growing in sodium-arsenite-containing soil by using rhizosphere pseudomonads. (2) The presence of pBS3031 offers the strains a certain selective advantage in arsenite-contaminated soil. (3) The presence of pBS3031 impairs plant growth, due to the As-resistance mechanism determined by this plasmid: the transformation of the less toxic arsenate into the more toxic, plant-root-available arsenite by arsenate reductase and the active removal of arsenite from bacterial cells. (4) Such a mechanism makes it possible to develop a bacteria-assisted phytoremediation technology for the cleanup of As-contaminated soils and is the only possible way of removing the soil-sorbed arsenates from the environment.     

Soil–Phosphorus Mobilization Potential of Phytate Mineralizing Fungi

Four most efficient phytase and phosphatase producing fungi belonging to genera Aspergillus, Trichoderma, and Penicillium were isolated from the rhizosphere soil of leguminous, cereal, and vegetable crops. Efficacy order of fungi in terms of phytate hydrolysis under laboratory conditions was Aspergillus > Penicillium > Trichoderma. The test fungi released more of extracellular (E) phytase than intracellular (I) phytase (E: I- 3.44 - 6.03:1) and produced acid phosphatase activity ranging from 367- 830 μmol pNP ml^?1 h^?1. Aspergillus niger possessed the twin ability of phosphate mineralization and solubilization. The incubation studies in compost-amended soil exhibited the higher competence of Penicillium chrysogenum to improve the soil available P and increase the level of extractable organic P under alkaline soil to benefit P nutrition. Developing microbial inoculant using P. chrysogenum strain and its subsequent application to soil may help the marginal farmer to replenish soil P more economically compared to chemical fertilizer.     

Chitinolytic and proteolytic activity of streptomycetes isolated from root-free soil,rhizosphere and mycorrhizosphere of pine (Pinus sylvestris L.)

Summary We tested 75 strains of Streptomyces spp. (25 taken from each environment of soil, rhizosphere, and mycorrhizosphere of pine, Pinus sylvestris L.) and all exhibited chitinolytic activity and hydrolysed gelatine and sodium caseinate in agar media. Enrichment of these media with glucose and NH₄NO₃ caused induction or stimulation of proteolytic Streptomyces spp. strains (80%) derived from root-free soil; inhibition of this activity was observed in most strains (92%) isolated from the root zone. The post-culture liquids of the rhizosphere strains cultured in the absence of glucose revealed a significantly higher proteolytic activity than those obtained from the root-free soil. The addition of glucose to the medium stimulated proteolytic activity in the post-culture broth of Streptomyces strains derived from soil and the mycorrhizosphere.     

Nodulation competition among Bradyrhizobium japonicum strains as influenced by rhizosphere bacteria and iron availability

Summary Bacteria isolated from the root zones of field-grown soybean plants [Glycine max (L.) Merr.] were examined in a series of glasshouse experiments for an ability to affect nodulation competition among three strains of Bradyrhizobium japonicum (USDA 31, USDA 110, and USDA 123). Inocula applied at planting contained competing strains of B. japonicum with or without one of eleven isolates of rhizosphere bacteria. Tap-root nodules were harvested 28 days after planting, and nodule occupancies were determined for the bradyrhizobia strains originally applied. Under conditions of low iron availability, five isolates (four Pseudomonas spp. plus one Serratia sp.) caused significant changes in nodule occupancy relative to the corresponding control which was not inoculated with rhizosphere bacteria. During subsequent glasshouse experiments designed to verify and further characterize these effects, three fluorescent Pseudomonas spp. consistently altered nodulation competition among certain combinations of bradyrhizobia strains when the rooting medium did not contain added iron. This alteration typically reflected enhanced nodulation by USDA 110. Two of these isolates produced similar, although less pronounced, effects when ferric hydroxide was added to the rooting medium. The results suggest that certain rhizosphere bacteria, particularly fluorescent Pseudomonas spp., can affect nodulation competition among strains of R. japonicum. An additional implication is that iron availability may be an important factor modifying interactions involving the soybean plant, B. japonicum, and associated microorganisms in the host rhizosphere.Paper No. 10648 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, NC 27695-7601, USA     

烟草根表可培养细菌群落组成及典型菌群的促生特性研究

植物微生物组是维护植物生长发育、提升抗逆防病的重要调控因素。为发挥植物微生物促进烟草生长、改善烟草根区微生态功能作用，本研究从烟草根表分离筛选可培养细菌组，并对不同菌株的促生能力进行测定。结果表明：①从烟草根表分离并鉴定出可培养菌株310株，隶属于31个属，其中主要为芽孢杆菌属(Bacillus)、假单胞菌属(Pseudomonas)；②对比分析发现假单胞菌属、芽孢杆菌属、寡养单胞菌属(Stenotrophomonas)和成对杆菌属(Dyadobacter)为4种供试土壤烟草根表共有的细菌类群；③对进一步筛选得到的16株菌株进行促生能力的测定，发现6株菌具有固氮能力，5株菌产铁载体，4株菌可溶解无机磷，4株菌产IAA；④盆栽试验验证16株菌株的促生效果，其中37.5% 的菌株对烟草生长具有显著促进作用，烟草株高、总鲜物质量和地下部干物质量分别比对照提高35.1%、27.9% 和30.7%。总之，从烟草根表分离获得多种具有促生能力的菌株，为未来构建促进烟草健康生长的复合菌剂提供了理论基础。