微生物制剂对肉鸡屠宰废水生物降解效果的研究

采用沼泽红假单胞菌、保加利亚乳杆菌,酵母菌和有效微生物群组成不同组合,以pH值、浑浊度、氨氮浓度、亚硝酸盐氮含量、BOD_5值和COD_(mn)值为考察指标,研究不同微生物制剂对肉鸡屠宰废水生物降效果,结果表明:沼泽红假单胞菌、保加利亚乳杆菌和有效微生物群以25:25:1的比例组成的复合微生物制剂,以0．01％为添加量时效果最好。     

低温热处理对超高温灭菌乳中假单胞菌脂肪酶Ⅷ的活性影响

通过分析不同因素对假单胞菌脂肪酶Ⅷ活性的影响以及假单胞菌脂肪酶Ⅷ活性与超高温灭菌(UHT)乳脂肪上浮的关系，研究了控制UHT乳中假单胞菌脂肪酶Ⅷ活性和延缓脂肪上浮现象的措施。结果表明pH值对假单胞菌脂肪酶Ⅷ的活性有显著性影响(P<0.01)，50、55、60℃(20 min)的低温热处理能显著降低假单胞菌脂肪酶Ⅷ的活性(P<0.01)。贮藏试验表明低温热处理对控制UHT乳在贮存过程中的假单胞菌脂肪酶Ⅷ活性水平(P<0.01)和脂肪上浮现象(P<0.05)有明显的作用，而55℃和15 min的低温热处理对缓解UHT乳在贮藏过程中的脂肪上浮现象最为有效。     

复合微生物制剂改善土壤生物学特性和防治烟草黑胫病的研究

烟草是我国重要的经济作物,利用微生物制剂改善土壤性质,防治烟草土传病害是实现绿色防控的重要途径.利用实验室已筛选的多功能有益微生物进行复配,研究了两种复合微生物制剂T1(芽孢杆菌、假单胞菌、不动杆菌)和T2(芽孢杆菌、假单胞菌、鞘氨醇菌)对土壤理化性质的影响以及对烟草黑胫病的防治效果.结果表明,与未施用微生物制剂的对照...     

沼泽红假单胞菌与枯草芽孢杆菌混施对水稻根域细菌多样性与功能的影响

[目的]微生物菌肥作为一种绿色环保的生物肥料,可以改善土壤质量,促进作物生长.以水稻根际和根表微生物为对象,探究不同微生物菌肥单施和混施对其群落多样性和功能的影响.[方法]采用盆栽试验,设单施沼泽红假单胞菌(Rhodopseudomonas palustris)、单施枯草芽孢杆菌(Bacillus subtilis)及...     

太湖地区水稻土优势反硝化细菌的数量、组成与酶活性

本研究结果表明太湖地区主要水稻土中反硝化细菌常在百万/克干土以上,占细菌总数的50—80%。同一类型土壤中,肥力高者含菌数多于肥力低者。各类土壤中反硝化细菌数与细菌总数呈显著正相关。其优势种中,以巨大芽孢杆菌、荧光假单胞菌和施氏假单胞菌等出现的机率最高,占反硝化细菌的10—50%;地衣芽孢杆菌及坚强芽孢杆菌等出现的机率较少。具有使NO₃^-还原为N₂O的菌株和使N₂O还原为N₂的菌株,分别占供试菌株的67%和56%;使¹⁵NO₃^-异化还原为¹⁵NH₄⁺的菌株占供试菌株的92%,其中以蜡质芽孢杆菌和地衣芽孢杆菌的这种能力特别强。     

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。     

不同气调包装方式的冷却猪肉在冷藏过程中的微生物变化

冷却猪肉分别采用真空包装、CO-MAP(CO+CO₂+N₂)包装、高氧-MAP(高浓度O₂+CO₂+N₂)和低氧-MAP(低浓度O₂+CO₂+N₂)包装后，在(4±1)℃贮存3周，每周测定各项微生物变化。结果表明：1)CO-MAP组可抑制腐败细菌的生长，除对乳酸菌抑制作用较弱外，对假单胞菌、肠杆菌科菌和热死环丝菌均具有很强的抑制作用     

低温热处理对超高温灭菌乳中假单胞菌脂肪酶的活性影响

通过分析不同因素对假单胞菌脂肪酶活性的影响以及假单胞菌脂肪酶活性与超高温灭菌(UHT)乳脂肪上浮的关系,研究了控制UHT乳中假单胞菌脂肪酶活性和延缓脂肪上浮现象的措施。结果表明pH值对假单胞菌脂肪酶的活性有显著性影响(P<0.01),50、55、60℃(20min)的低温热处理能显著降低假单胞菌脂肪酶的活性(P<0.01)。贮藏试验表明低温热处理对控制UHT乳在贮存过程中的假单胞菌脂肪酶活性水平(P<0.01)和脂肪上浮现象(P<0.05)有明显的作用,而55℃和15min的低温热处理对缓解UHT乳在贮藏过程中的脂肪上浮现象最为有效。     

气调包装对冷却肉护色保鲜效果的研究

不同气体成分比例和不同包装材料影响冷却肉的贮藏保鲜品质。本研究通过填充不同比例的CO、CO₂和N₂,结合不同阻隔性能的包装材料,分析气调包装对冷却肉护色保鲜的效果。结果表明当充气比例为1%CO、25%CO₂和74%N₂时冷藏21d,冷却肉的出水率为1.54%,红度值(a*)值最大,细菌总数增加量最少,挥发性盐基氮含量最低,色泽、风味和外观感官性能最佳,综合护色保鲜效果最优。同时,高阻隔性的包装材料能显著性地维持冷却肉的色泽,降低失水率,抑制微生物的生长。本研究显示适宜的气体成分组成配合高阻隔性的包装材料,更加有利于冷却肉的护色保鲜。     

4株红螺菌科细菌的拮抗作用及其影响因素

对4株红螺菌(荚膜红假单胞菌PSB-2、球形红假单胞菌PSB-3、胶质红假单胞菌H1和沼泽红假单胞菌H10)的去细胞上清液(CFS)抑制水产养殖病原菌的作用进行研究,并探讨养殖水体环境对红螺菌拮抗作用的影响.结果表明,4株红螺菌在细胞生长稳定期后能有效分泌拮抗物质,其去细胞上清液(CFS)对20多株水产养殖病原菌均有抑制作用.从抑菌活性看,荚膜红假单胞菌的抑菌活性强于其他菌株:荚膜红假单胞菌对水产养殖病原菌的最低抑菌浓度(MIC)为8～64 AU/mL,而其他红螺菌株多为4～16 AU/mL.在养殖水体的生态因子中,水体pH、NH4 -N与NO2--N对红螺菌代谢产物的抑菌活性影响较大,pH7～9,NH4 -N低于5 mg/L、NO2--N浓度低于7mg/L时抑菌活性较强,而养殖水体温度与溶氧变化对红螺菌的抑菌活性基本无影响作用.     

The role of “effective microorganisms” in the composting of banana (Musa ssp.) residues

“Effective microorganisms” (EM) are a poorly defined mixture of supposedly beneficial microorganisms that are claimed to enhance microbial turnover in compost and soil. In Costa Rica, EM are used to produce organic compost (bokashi) from banana residues (Musa ssp.). Given the scarcity of scientific data about the effects of EM on the mineralization of plant residues, this study aimed at investigating the effects of EM addition on the decomposition of banana residues during Bokashi production. To this end, the following non‐EM treatments were compared to EM Bokashi: Bokashi produced with water (W), with molasses (M) as an EM additive, and with sterilized EM (EMst). Subsequently, the effects of the resulting Bokashi treatments on the growth of young banana plants were evaluated. Compared with non‐EM controls, the effect of EM on the mineralization of banana material was negligible. Dry‐matter losses of the composts with different EM treatments were similar, with about 78% over 5 weeks. Ergosterol concentration was highest in EM Bokashi (77 µg (g dry soil)^–1) and lowest in EMst Bokashi (29 µg (g dry soil)^–1). Microbial biomass carbon (C_mic) and microbial biomass nitrogen (N_mic) were both lowest in EM (C_mic = 3121 µg g^–1; N_mic = 449 µg g^–1), while C_mic was highest in Bokashi produced with molasses (3892 µg g^–1) and N_mic was highest in EMst (615 µg g^–1). Treatment effects on adenylate concentrations and adenylate energy charge were negligible. Application of all Bokashi variants to young banana plants significantly increased shoot growth under greenhouse conditions compared to plants grown in a control soil without amendments. However, these effects were similar for all Bokashi treatments, even if EM Bokashi increased the K concentrations in banana leaves significantly compared to Bokashi produced with EMst and the control. Bokashi produced with only molasses and EM Bokashi decreased the number of root nematodes under greenhouse conditions compared to the control. Overall, the results confirmed the expected influence of composting on the degradation of organic material and the effect of compost application on plant growth. Hower, under the conditions of this study, EM showed no special effects in this, except for increasing the K concentrations in the leaves of young banana plants.     

模拟降水和氮沉降对准噶尔盆地南缘梭梭光合生理的影响

氮沉降和降水格局变化是目前全球气候变化背景备受关注的热点研究课题,也是荒漠生态系统的两个主要限制因子。因此,研究两者对荒漠植物的效应有助于深入了解荒漠生态系统对全球变化的响应。本文选择准噶尔盆地南缘荒漠地区的建群种梭梭(Haloxylon ammodendron)作为研究对象,设置自然降水(W0)与增加降水30%(W1)两个水分条件和自然氮沉降(N0)、增加氮素30 kg(N)·hm~(-2)·a~(-1)(N1)与增加氮素60kg(N)·hm~(-2)·a~(-1)(N2)3个施氮水平,连续处理2年,以探究降水、氮沉降及其交互作用对梭梭光合日变化及生理生态特征的影响。结果表明:降水、氮沉降及其交互作用对梭梭的净光合速率(Pn)日变化产生极显著正相关影响;同时根据梭梭Pn、胞间CO2浓度(Ci)及气孔限制值(Ls)的变化方向,推测梭梭光合"午休"主要由非气孔因素引起。此外,W0条件下,梭梭丙二醛(MDA)含量、抗氧化酶(POD、CAT、SOD)活性、可溶性蛋白(Pr)和可溶性糖(SS)含量均随施氮量增加而显著降低,脯氨酸(Pro)含量则呈先降低后增加的趋势;而W1条件下,梭梭MDA含量、抗氧化酶(POD、CAT、SOD)活性及渗透调节物质(Pro、Pr、SS)含量均随施氮量增加呈显著先增加后降低的趋势。两种水分条件下,除W1N1处理梭梭的Pro含量高于对照组外,其余处理均显著低于对照组;同时梭梭的MDA含量、抗氧化酶活性、Pr及SS含量也均显著低于对照组。综合分析结果表明:降水、增氮及其交互作用均有利于梭梭的生长,但其交互作用效应的强弱则取决于二者间的比例。     

狗牙根与空心莲对水库消落带土壤氮磷释放影响的模拟

通过水库水位涨落室内模拟试验,探究丹江口库区消落带优势物种狗牙根和空心莲2种草本植物对土壤氮磷释放过程影响。结果表明:(1)水淹结束后(32天),空心莲子草土壤TN、TP分别降低11.75%,25.28%,狗牙根分别降低3.62%,25.77%。(2)干湿交替环境主要影响土壤中NH_4~+-N、NO_3~--N和AP的含量的变化,对土壤中的TN、TP含量的影响较小。(3)狗牙根的死亡增加土壤TN、NH_4~+-N、TP量,即不耐淹植被过滤带虽然能净化径流中N、P等污染物,但截留的污染物和植物吸收的养分随着植物体的分解再次进入水体或土壤,无法达到有效防控农业面源污染的目的。该研究为丹江口水库利用植被缓冲带防控水体富营养化提供一定理论依据。     

有机肥部分替代化肥氮对叶菜产量和环境效应的影响

针对叶菜类蔬菜有机肥氮替代化肥氮的最佳替代比例及对经济效益和环境效应综合评价较缺乏等问题,本研究采用田间试验,对包心菜和小青菜进行等氮水平下不同比例有机肥替代化肥处理,包括:纯化肥氮(0M),25%、50%、75%和100%有机肥替代化肥(25%M、50%M、75%M和100%M),研究不同处理下蔬菜产量、经济效益、土壤氨挥发和氧化亚氮排放。结果表明, 25%M处理下包心菜和小青菜产量均达最高,且与0M处理相比包心菜和小青菜的产量分别增加15.0%(P0.05)和16.3%(P0.05)。25%M比0M处理经济效益分别增加11.7%和5.4%,但在50%M、75%M和100%M处理下经济效益为负增长。25%M处理下,氨挥发累积排放量在包心菜和小青菜季分别为42.1kg·hm~(-2)和12.9kg·hm~(-2),比0M处理分别降低23.4%(P0.05)和41.6%(P0.05); 0M和25%M处理间氧化亚氮累积排放量无显著差异, 25%M处理在包心菜和小青菜季的氧化亚氮累积排放量分别为0.74 kg·hm~(-2)和3.06 kg·hm~(-2);与25%M处理相比, 50%M、75%M和100%M处理下氧化亚氮排放分别增加33.7%～60.8%(P0.05)、50.0%～134.3%(P0.05)和56.8%～185.6%(P0.05)。基于此,提出叶菜类蔬菜有机肥氮替代化肥氮的适宜替代比例在25%左右时可实现最佳的增效减排效果。     

光强和施氮量对催吐萝芙木生长及生物量的影响

通过不同光强(15%、40%和70%自然光强)和施氮量(15g·株-1、30g·株-1和60g·株-1)的盆栽试验,研究了不同光照强度和施氮量对催吐萝芙木生长和生物量的影响。结果表明:光强和施氮量显著影响催吐萝芙木的生长、单株生物量及生物量分配(P0.05)。在70%自然光强下,催吐萝芙木株高、地径、株高和地径的相对生长速率(RGRH,RGRD)、单株生物量都较15%和40%自然光强下高,并分配更多的生物量到地下部分。在15%和40%自然光强下,催吐萝芙木的株高、地径、RGRH、RGRD、单株生物量随施氮量的增加而减小;在70%自然光强下,催吐萝芙木在30g·株-1中等施氮量下生长最好,单株生物量最大,达559.6g·株-1。在相同光强下,催吐萝芙木根生物量比(RMR)和根冠比(R/S)随施氮量增加而减小,比叶面积(SLA)和叶生物量比(LMR)在低光强和高施氮量下最大。从株高、地径、RGRH、RGRD、单株生物量、RMR和R/S等指标看,70%自然光强和30g·株-1的施氮量是催吐萝芙木最佳的光强和施氮量组合。     

模拟氮沉降对华北落叶松人工林土壤微生物碳和微生物氮的动态影响

为揭示过量的大气氮沉降对华北落叶松人工林土壤微生物碳、氮和土壤呼吸的影响,通过对照(N0:0 g/(m^2·a))、轻度施氮(N1:8 g/(m^2·a))、重度施氮(N2:15 g/(m^2·a))3个外源施氮水平下5年的野外定点试验和观测,模拟过量氮沉降条件下华北落叶松人工林土壤微生物碳、氮和土壤呼吸的变化,旨在阐明林下土壤微生物和呼吸对过量氮沉降的响应及其对土壤碳氮循环的影响。结果表明:在5-10月生长季中,土壤微生物碳和氮的平均含量分别为1 098.93,97.31 mg/kg,二者都随土层深度的增加呈下降趋势;轻度施氮促进土壤微生物碳和氮的增加,重度施氮抑制土壤微生物碳和氮的增加;土壤微生物碳和微生物氮从生长初期5月起,5-7月呈增加趋势,7月出现峰值,8月降低,9-10月小幅增加,呈现"N"形曲线。土壤微生物碳氮比为4.94~18.54,且随施氮量增加而减小。各氮处理下,华北落叶松人工林土壤呼吸速率5,6月较低,7-8月持续增加,并在8月达到最高,9-10月逐渐降低。相关分析表明,土壤呼吸与土壤全氮、含水量、微生物碳和微生物氮含量呈极显著正相关关系,与土壤有机质呈显著正相关关系。在全球变化背景下,研究结果可为进一步明确过量大气氮沉降对森林生态系统碳氮循环的影响途径和机制研究提供重要参考。     

Comparison of three field methods for measuring ammonia volatilization from urea granules broadcast on to pasture

Urea granules were broadcast on to pasture (Lolium perenne/Trifolium repens) at a rate of 100 kg N ha^?1. The evolution of NH₃ from the soil was measured using three methods: an enclosure system with continuous air flow (EM), an unconfined micrometeorological method (integrated horizontal flux method—IHFM) and by measuring the recovery of N as urea, NH₄⁺ and NO₃^? (NRM). The cumulative loss after 96 h measured by the three methods was 24%, 25% and 30% of the N applied respectively. After 144 h the daily rate of loss was small. At this time, EM and IHFM estimated the loss at 28%, while the NRM estimated a 45% loss. The higher estimated loss by the NRM was attributed mainly to microbial immobilization of applied N. Hourly fluxes estimated by the EM and the IHFM were very different. This was attributed to variations in the rate of urea hydrolysis which appeared to be more rapid in the confined EM system where the rate of soil drying was slower.     

模拟氮沉降对一年生香椿幼苗生长和光合特性的影响

为研究氮沉降对一年生香椿(Toonasinensis)幼苗夏季生长以及光合特性的影响,通过在夏季模拟氮沉降控制试验,以尿素为氮源供体,设置0kg(N)×hm~(-2)×a~(-1)(CK)、20kg(N)×hm~(-2)×a~(-1)、40kg(N)×hm~(-2)×a~(-1)、80kg(N)×hm~(-2)×a~(-1)、120 kg(N)×hm~(-2)×a~(-1)、180 kg(N)×hm~(-2)×a~(-1)不同氮添加水平以模拟氮沉降,对香椿幼苗地径、苗高、生物量及其分配和光合作用等进行研究。结果表明:1)不同氮添加量均促进了香椿幼苗地径、苗高和生物量的增加,地径、苗高和生物量均以氮添加水平180kg(N)×hm~(-2)×a~(-1)下最高,分别较CK高42.5%、64.4%和304.9%,且生物量向根、叶分配较多; 2)香椿幼苗叶片相对叶绿素含量(SPAD)随氮添加水平的增加而增加,在180 kg(N)×hm~(-2)×a~(-1)下最高,较CK增加73.9%;3)香椿幼苗表观量子效率(AQY)、最大净光合速率(Pnmax)、光饱和点(LSP)、光补偿点(LCP)以及暗呼吸速率(Rd)随氮添加水平的增加均呈现先升高后降低的趋势,其中LCP以80 kg(N)×hm~(-2)×a~(-1)下最高, AQY、Pnmax、LSP和Rd均以120kg(N)×hm~(-2)×a~(-1)下最高。结果表明,适量氮沉降能够促进香椿幼苗生长和光合能力的提高,但更高水平的氮沉降可能对香椿幼苗产生一定抑制作用。     

Determinants of trophic modes of the nematophagous fungus Arthrobotrys oligospora interacting with bacterivorous nematode Caenorhabditis elegans

The determinants of saprotrophic or predatory modes of the nematophagous fungus Arthrobotrys oligospora were investigated in soil microcosms and on solid nutrient media. A sterilized soil amended with 1% w/w alfalfa meal (C:N=32) and inoculated with conidia of A. oligospora, showed lower mycelium biomass and higher specific rate of conidia production in the presence of the bacterivorous nematode Caenorhabditis elegans than in its absence. As few as 10 nematodes g⁻¹ soil were sufficient to enhance spore formation by the vegetative mycelium. Given that the fungus was not limited by available carbon and nitrogen, this indicates that nematodes provide essential growth factors regulating the development of A. oligospora. Carbon mineralisation by A. oligospora, measured as the rate of CO₂ production, was found to be 25–35% lower in the presence of 20–60 C. elegans g⁻¹ soil compared to soil without nematodes. This showed that A. oligospora had lower saprotrophic activity in the predaceous phase. Trap formation and nematophagous activity of A. oligospora were observed only where conidia were inoculated on nutrient poor medium (water agar), on low-nitrogen medium (Yeast Carbon Base agar) or on medium containing no amino-acids or vitamins (Czapek-Dox agar). A. oligospora did not form trapping structures when grown on nutrient-rich media containing three amino-acids (l-histidine monohydrocloride, dl-methionine and dl-tryptophan) and vitamins (biotin, calcium pantothenate, folic acid, inositol, niacin, p-aminobenzoic acid, pyridoxine hydrochloride, riboflavine, thiamine hydrochloride). It is concluded that predaceous behaviour of A. oligospora can be regulated either by nitrogen sources or by physiologically active compounds (amino-acids or vitamins) present in nematodes.