2种菌联合修复农田土壤镉污染的研究

采用盆栽试验,运用BCR四步法、火焰原子吸收法和稀释涂布平板法等方法,研究了沼泽红假单胞菌(Rhodopseudanonas palustris)和枯草芽孢杆菌(Bacillus subtilis)联合作用对修复农田土壤重金属镉污染盆栽种植小白菜(Brassica campestris L. ssp.chinensis Makino)的效果及安全性,旨在探讨降低土壤镉生物有效性的有效途径,为新型生物菌肥研究提供理论依据。结果表明,沼泽红假单胞菌、枯草芽孢杆菌单独作用以及联合作用均能使农田土壤中镉的固定态增加,降低农田土壤中镉的生物有效性,联合菌处理组镉的生物有效性降低最显著,为32.70%,均对农田土壤中微生物各生理类群数量有显著性影响(P0.05),其中,细菌的数量达到10~5 CFU/g;均显著降低了小白菜根、茎中镉含量,联合菌处理组根、茎中镉的去除率分别达到58.06%～71.37%和73.66%～76.70%;均增加了小白菜株高、茎鲜重、叶绿素a、b的含量和叶绿素a/b的比值,联合菌处理组小白菜的生物量增加18.13%～69.55%。研究结果说明,沼泽红假单胞菌和枯草芽孢杆菌联合作用,对农田土壤镉污染的修复效果显著,且促进了小白菜的生长,具有修复农田土壤重金属污染的潜力。     

土壤食细菌线虫对菲降解的影响

以菲作为多环芳烃污染物的代表,通过室内培养试验研究了在菲降解菌恶臭假单胞菌存在与否的条件下,接种食细菌线虫对未灭菌土壤中菲去除的影响。析因设计包括4个处理:单独接种恶臭假单胞菌(B),单独接种食细菌线虫(N),同时接种食细菌线虫和恶臭假单胞菌(BN)以及未接种线虫和细菌的对照(CK);分别在培养后第0、5、14、28天进行破坏性采样,测定土壤中菲的残留量,食细菌线虫和恶臭假单胞菌的数量,土壤FDA(荧光素二乙酸酯)水解酶、过氧化氢酶的活性。结果显示,相比CK,在培养前期(0~14天),处理N提高土壤中菲的去除率;而在培养后期(14~28天),BN处理降解菲的优势逐渐显现出来。在培养结束(28天)时,各处理菲的去除率依次为BN(48.2%)B(45.1%)N(44.4%)CK(43.5%)。试验结果还表明,接种食细菌线虫能显著(p0.05)促进细菌以及土壤酶活性。总之,食细菌线虫和细菌的交互作用可能促进土壤中菲的降解。     

恶臭假单胞菌P861(Gus)在油菜根部定殖的生态研究

本研究采用Gus 基因标记技术和常规方法跟踪考察了恶臭假单胞菌P861(Gus) 在缩影系统油菜根圈的定殖情况,以及缩影系统内土壤类型、土壤含水量对根部定殖的影响。土壤含水量分别为60% FC和75% FC时,P861(Gus) 在砂姜黑土中的定殖水平高于50% FC的,不但能散布至种子下8cm 以内的根段部位,且定殖水平分别为7.5×10²和2.8×10³cfu·g^-1。在灰潮土缩影中,P861(Gus) 在油菜根圈的定殖动态表现为在油菜播种后3 ～6 天,定殖密度可达最高水平(5.5×10⁶cfu·g^-1) ,然后急速下降,最后保持在一个相对稳定的较低水平(7.6×10²cfu·g^-1) 。P861(Gus) 在不同根段部位的定殖密度并无从上到下逐渐递减的规律。     

微观水分和养分条件对铜绿假单胞菌噬菌体裂解宿主过程的影响

摘 要：【目的】研究不同水分和养分条件下,细菌和噬菌体的生长和运移规律、细菌和噬菌体种群互作过程以及其对群落结构的影响和调控机制。【方法】通过控制微生物运动平板表面相对水膜厚度研究铜绿假单胞菌（Pseudomonas aeruginosa PAO1）和铜绿假单胞菌噬菌体PA-27-1（Pseudomonas phage PA-27-1）的互作过程。【结果】细菌和噬菌体的互作主要受噬菌体裂解细菌、细菌的运动和噬菌体扩散三个因素控制。水分通过调控多孔表面水膜的厚度和连通性来改变细菌在微孔尺度的运动,进而影响微生物在粗糙界面的增殖和生物膜的形成过程以及菌落的形态特征,同时通过影响噬菌体的扩散传播来调节细菌和噬菌体之间的互作机制。细菌与噬菌体自身运动性及个体大小上的不同也导致二者在微观孔隙中增殖（扩散）特征的差异。相对低水膜网络促进了细菌和噬菌体之间的空间隔离,降低了噬菌体有效侵染细菌的概率,从而有利于细菌的增殖。丰富的养分条件有利于细菌生物量的快速繁殖,进而促进噬菌体的增殖。【结论】本研究揭示了环境生物膜等微生境中噬菌体和宿主细菌的生长和运移规律,有助于为深入理解土壤噬菌体的时空分布特征与演变规律以及其与土壤细菌之间的互作模式提供理论基础和数据支撑。     

恶臭假单胞菌P861(Gus)在油菜根部定殖的生态研究

本研究采用Gus 基因标记技术和常规方法跟踪考察了恶臭假单胞菌P861(Gus) 在缩影系统油菜根圈的定殖情况,以及缩影系统内土壤类型、土壤含水量对根部定殖的影响。土壤含水量分别为60% FC和75% FC时,P861(Gus) 在砂姜黑土中的定殖水平高于50% FC的,不但能散布至种子下8cm 以内的根段部位,且定殖水平分别为7.5102和2.8103cfug-1。在灰潮土缩影中,P861(Gus) 在油菜根圈的定殖动态表现为在油菜播种后3 ～6 天,定殖密度可达最高水平(5.5106cfug-1) ,然后急速下降,最后保持在一个相对稳定的较低水平(7.6102cfug-1) 。P861(Gus) 在不同根段部位的定殖密度并无从上到下逐渐递减的规律。     

细菌生物学特性对其生物膜形成的影响

Biofilm-associated microorganisms play crucial roles in terrestrial and aquatic nutrient cycling and in the biodegradation of environmental pollutants.Biofilm formation was determined for a total of 18 bacterial isolates obtained from the biofilms of wastewater treatment systems and of little carpolite in soil.Among these isolates,seven showed strong biofilm-forming capacity.The phylogenetic affiliation of the isolates showing high biofilm formation capacity was determined through 16S rDNA sequencing and the isolates were grouped into 7 bacterial species including Pseudomonas sp.,Pseudomonas putida,Aeromonas caviae,Bacillus cereus,Pseudomonas plecoglossicida,Aeromonas hydrophila,and Comamonas testosteroni.The biofilm-forming capacity was closely related with flagella,exopolysaccharide,and extracel-lular protein.According to the coefficient of determination,the relative importance of the five biological characteristics to biofilm formation was,in order from greatest to least,exopolysaccharide > flagella > N-acyl-homoserine lactones (AHLs) signaling molecules > extracellular protein > swarming motility.     

过路黄叶斑病病原鉴定及拮抗细菌的筛选

为明确贵州省施秉县过路黄叶斑病的病原种类,探索该病害的生物防治方法,本试验利用组织分离法、致病性测定法获得致病菌株GLHYB,并结合形态学特征和基于内转录间隔(ITS)、β-微管蛋白(β-tubulin)、延伸因子(EF-1α)3个基因构建系统发育树,将该菌株鉴定为腐皮镰刀菌(Fusarium solani).利用组织...     

接种耐铬细菌菌株对二月兰中铬积累及其生长状况的影响

Beneficial interactions between microorganisms and plants, particularly in the rhizosphere, are a research area of global interest. Four cadmium （Cd）-tolerant bacterial strains were isolated from heavy metal-contaminated sludge and their effects on Cd mobility in soil and the root elongation and Cd accumulation of Orychophragmus violaceus were explored to identify the capability of metal- resistant rhizobacteria for promoting the growth of O. violaceus roots on Cd-contaminated soils. The isolated strains, namely, Bacillus subtilis, B. cereus, B. megaterium, and Pseudomonas aeruginosa, significantly enhanced the plant Cd accumulation. The Cd concentrations in the roots and shoots were increased by up to 2.29- and 2.86-fold, respectively, by inoculation of B. megaterium, as compared with the uninoculated control. The bacterial strains displayed different effects on the shoot biomass. Compared with the uninoculated plants, the shoot biomass of the inoculated plants was slightly increased by B. megaterium and significantly decreased by the other strains. B. megaterium was identified as the best candidate for enhancing Cd accumulation in O. violaceus. Thus, this study provides novel insight into the development of plant-microbe systems for phytoremediation.     

柑橘溃疡病菌的拮抗细菌Bv10的研究

从广西合浦县柑橘叶片表面分离到拮抗细菌菌株Bv10。该拮抗细菌对柑橘溃疡病菌的生长表现出很强的拮抗活性。根据16S rDNA序列同源性比较、形态学特征以及生理生化反应,将该菌株鉴定为枯草芽孢杆菌B acillus subtilis变种。在温室接种测试中,42.9%的柑橘溃疡病斑形成受到Bv10菌株的抑制。Bv10菌株在人工培养基上连续移植8次,对柑橘溃疡病菌生长的抑制力没有显著变化,该菌株表现对植物病原真菌具有较宽的抑菌谱。     

铜绿假单胞菌对镉胁迫水稻苗期生长与镉积累的影响

稻米重金属污染是人们广泛关注的严重问题,微生物钝化是阻遏环境重金属进入生物循环的有效途径之一。为了解铜绿假单胞菌对苗期水稻镉污染的缓解效应,本文以无镉处理为对照,通过添加20μmol×L~(-1)镉的水培试验,研究了铜绿假单胞菌、载体A(硅藻土,粒径1~3 mm)、载体B(硅藻土,粒径3~6 mm)、载体C(活性炭,比表面积1 000 m~2×g-1)以及铜绿假单胞菌与载体制备的菌剂A、菌剂B和菌剂C对水稻生长、镉含量及镉积累量的影响。结果表明,20μmol×L~(-1)镉处理显著抑制了水稻根长、株高的生长和干物质积累,添加菌液及菌剂A、B、C后,水稻生长状况得到显著改善,总生物量比镉处理(0.523 g×株~(-1))提高38.5%~67.3%,以菌剂B处理的水稻生物量最高。水稻根、茎鞘、叶以及地上部镉含量显著降低,其中添加菌剂A、菌剂B、菌剂C及活性炭处理的水稻地上部镉含量分别比镉处理(101.3 mg×g~(-1))下降45.9%、47.9%、59.9%和59.9%,迁移系数降低16.7%、25.0%、33.3%和33.3%,富集系数减少48.1%、48.8%、58.8%和60.9%。添加活性炭、菌剂A和菌剂C处理的水稻单株镉积累量降低18.2%、9.5%和24.3%,添加菌剂B以及依次含有56.4 mL、45.3 mL、28.4 mL菌悬液的菌液A、菌液B和菌液C处理,其镉积累量依次增加15.0%、30.4%、14.9%、16.9%,说明菌株通过提高作物生物量增加了镉积累。综上,铜绿假单胞菌可显著促进镉胁迫水稻的生长,降低水稻的镉含量,抑制镉的迁移,降低水稻镉的有效性;菌剂A、B、C表现出良好的镉钝化能力,表明铜绿假单胞菌可为环境镉污染的生物修复提供新菌株。     

我国不同地区杨树根际磷细菌的分离与鉴定

A few soil microorganisms can convert insoluble forms of phosphorus(P) to an accessible form to increase plant yields.The objectives of this study were to isolate,screen and identify the phosphobacteria,i.e.,phosphate-solubilizing bacteria(PSB) and phosphate-mineralizing bacteria(PMB),in some poplar plantations and to select potential microbial inoculants that could increase the P uptake by plants.Seventy four PSB strains and 138 PMB strains were preliminarily screened from 797 colonies isolated from the rhizosphere soil of poplar by the visible decolorization in the National Botanical Research Institute’s phosphate growth medium(NBRIP) containing a pH indicator of bromophenol and by the clear/halo zone on yeast malt agar plate,respectively.Then,based on the solubilization of Ca 3(PO 4) 2 in liquid NBRIP medium and the mineralization of lecithin in liquid Menkina medium,15 PSB strains and 7 PMB strains were further determined for their abilities to solubilize Ca 3(PO 4) 2 and to mineralize lecithin.The results showed that the 15 PSB strains exhibited inorganic P-solubilizing abilities ranging between 376.62 and 669.56 mg L -1 and the 7 PMB strains exhibited organic P-mineralizing abilities varying from 0.32 to 1.56 mg L -1 three days after incubation.Three of PSB strains with the highest P-solubilizing ability,named JW-JS1,JW-JS2 and JW-SX2,were all preliminarily identified as Pseudomonas fluorescens,while two of PMB strains with the highest P-mineralizing ability,named JYZ-SD1 and JYT-JS2,were preliminarily identified as Bacillus cereus and Bacillus subtilis,respectively.All the efficient PSB and PMB strains should be further studied under both pot culture and field conditions to test their beneficial effects on poplar.     

接种方式对堆肥过程中功能菌定殖的影响

利用园林绿化废弃物添加磷矿粉,在堆肥前期、后期以及前后期分两次接种复合菌剂进行好氧堆肥,通过抗生素标记、选择性培养基方法,研究堆肥过程功能菌（解磷菌、拮抗菌）的定殖状况,分析堆肥产品的微生物群落功能多样性、解磷效果以及对青枯病菌的拮抗性能。结果表明：堆肥后期和分前后两次接种复合菌剂明显增加堆肥枯草芽孢杆菌、胶质芽孢杆菌功能菌数量,而前期接种经过堆肥高温期,堆体功能菌数量锐减,表明功能菌定殖效果取决于是否后期接种;堆肥后期和分前后两次接种显著提高了堆肥的微生物群落功能多样性、堆肥水溶性磷和有效磷含量以及堆肥对青枯病菌拮抗性能。     

Effects of seed priming with plant growth-promoting rhizobacteria on wheat yield and soil properties under contrasting soils

In the present investigation, different strains of Plant growth-promoting rhizobacteria (PGPR), namely Bacillus megaterium, Pseudomonas fluorescens and Bacillus subtilis were evaluated for their growth-promoting effects on wheat as well as on soil properties under field conditions at two different sites having sandy loam and silt loam type of soils. PGPR strains were evaluated either singly or in consortia. Amongst all the treatments, wheat inoculated with consortia was found most effective as it increased grain yield up to 53% over control in silt loam soil, whereas, corresponding effects in sandy loam soil were less pronounced as an increase of 31% was observed in corresponding treatments, respectively. Enhanced effects on soil properties were also more intense in silt loam as there was an increase of 205% organic matter as against sandy loam soil where this value was 110%.     

稀土元素钕对铜绿微囊藻生长和生理特性的影响

通过模拟培养试验,研究了不同Nd3＋初始浓度条件下铜绿微囊藻（Microcystis aeruginosa）的生长及生理变化。结果表明,相对BG11培养基（Nd3＋初始浓度为0 mg.L-1）,低初始Nd3＋浓度（0.01、0.05、0.1、0.5、1 mg.L-1）条件下,随着Nd3＋浓度的增加,藻细胞中叶绿素a含量、可溶性蛋白含量和过氧化氢酶（CAT）活性均呈增加趋势,促进了铜绿微囊藻生长;在Nd3＋初始浓度为5 mg.L-1和10mg.L-1时,藻细胞丙二醛（MDA）含量急剧增加,CAT活性下降,藻细胞清除活性氧（ROS）能力下降,抗氧化防御体系被破坏,膜脂过氧化严重,严重抑制藻细胞生长,在初始Nd3＋浓度50 mg.L-1胁迫下,铜绿微囊藻无法生长。藻细胞超微结构表明,过量的Nd3＋破坏了藻细胞内的类囊体结构,胞内脂质体含量增加,细胞膜变粗糙甚至变形破碎,对藻细胞造成不可逆伤害。     

海洋枯草芽孢杆菌UMBR1027产抑金黄色葡萄球菌活性蛋白分离鉴定及发酵条件优化

金黄色葡萄球菌(Staphylococcus aureus)是一种能引起严重传染性疾病的人兽共患病原菌,由于其严重的致病性及其易产生耐药性的特点,使得探索新的具有活性的药物的需求越发迫切.为了研究对S.autrgus有抑制作用的活性蛋白,本实验采用硫酸铵沉淀法对海洋枯草芽孢杆菌(Bacillus subtilis)UMBR1027产抑S.aureus活性蛋白进行提取,并利用葡聚糖凝胶SephadexLH-20柱层析、十二烷基硫酸钠聚丙烯酰胺(sodium dodecyl sulfate polyacrylamide gel electrophoresis,SDS-PAGE)凝胶电泳进行分离、ABI 4800 plus MALDI-TOF进行鉴定;为了提高活性蛋白在B.subtilis UMBR1027发酵过程中的产量实验采用滤纸片扩散法,以抑菌圈直径为指标,分别从培养基pH、培养基的盐度以及培养温度这3个关键因素对B.subtilis UMBR1027产抑S.aureus活性蛋白的影响进行考察,并设计Box-Behnken实验以优化其发酵条件.结果显示活性蛋白主要含有碱性丝氨酸蛋白酶、α-淀粉酶、枯草杆菌蛋白酶和内切-β-1,3-1,4葡聚糖酶,优化实验得出B.subtilis UMBR1027产活性蛋白的最佳发酵条件组合为培养基pH为6.95、培养基盐度为10.38％、发酵培养温度为34.95℃;拟合实验中选取发酵培养基pH为6.95,发酵培养基盐度为10.38％,发酵温度为35℃进行验证,抑菌圈直径为20.4 mm,与理论值基本吻合.本研究对B.subtilis UMBR1027所产抗菌粗蛋白进行了分离,并成功对抗菌粗蛋白分离纯化后的各个部分进行了鉴定.响应曲面法有效提高了B.subtilis UMBR1027产抑制S.aureus的抗菌蛋白类物质,此研究为探索来自海洋的活性抗菌蛋白类天然药物分子提供了理论依据.     

含枯草芽孢杆菌肥料对大豆叶片光合作用及土壤酶活性的影响

为了减少大豆生产过程中化肥的施用量及对黑土地的保护,开展大豆田间试验,分别施用大豆专用复合肥(CK)、枯草芽孢杆菌+氨基酸型有机肥(T1)、枯草芽孢杆菌+黄腐酸钾肥(T2)、枯草芽孢杆菌+海藻精粉颗粒肥(T3)、枯草芽孢杆菌秸秆腐熟有机肥(T4)、枯草芽孢杆菌鸡粪腐熟有机肥(T5),综合评价各种肥料对大豆光合作用和土壤...     

铜绿假单胞菌生物降解特性的研究进展

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