梨渣固态发酵培养多粘类芽孢杆菌的工艺

为了充分利用梨渣这一资源,该文以新鲜鸭梨渣为主要原料,采用固态发酵方式,研究了梨渣与麸皮比例、外加氮源、无机盐、装瓶量、培养温度和时间对生防用多粘类芽孢杆菌D1生长及产芽孢的影响。研究发现,梨渣是一个良好的固态发酵原料,适合培养多粘类芽孢杆菌。当梨渣与麸皮的质量比为5∶2时,获得最大活细胞数,为2.5×109 cfu/g。向梨渣发酵培养基中添加尿素、硝酸钠和豆饼粉可明显提高活菌数和芽孢数,其中添加豆饼粉的效果较好。培养基中添加质量分数为0.5%磷酸二氢钾极大地促进了菌体生长和芽孢的形成。随着培养基装瓶量的增加,芽孢数也随之明显减少。多粘类芽孢杆菌D1的较适培养温度为34°C,较适培养时间为120 h。适宜培养条件下的活菌数、芽孢数和芽孢率分别为5.09×109 cfu/g、4.78×109 cfu/g和93.9%。该研究结果为利用梨渣发酵生产多粘类芽孢杆菌菌剂提供参考。     

多粘类芽孢杆菌BRF-1和枯草芽孢杆菌BRF-2对黄瓜和番茄枯萎病的防治效果

采用室内培养方法,对生防细菌多粘类芽孢杆菌BRF-1和枯草芽孢杆菌BRF-2不同稀释倍数的代谢产物抑制黄瓜尖孢镰刀菌、番茄枯萎病菌分生孢子萌发和菌丝生长的试验结果表明,当两菌株代谢产物稀释5倍时,对分生孢子萌发的抑制率达到80％以上;两菌株代谢产物在稀释2倍和5倍时,对2种病原真菌菌丝生长的抑制率在40％-80％之间,与对照差异极显著（P〈0．01）。盆栽试验表明,BRF-1和BRF-2生防细菌菌悬液及其无菌代谢物对黄瓜和番茄枯萎病不仅具有较好的防治效果,而且具有明显的促进生长作用。     

施用多粘类芽孢杆菌与木本生物炭对紫苏吸收镉的影响

目的探究不同程度镉污染土壤中添加多粘类芽孢杆菌和木本生物炭对紫苏植株吸收镉的差异,为在镉污染土壤上安全种植紫苏提供技术支撑和理论依据。方法以采自赣州的镉污染土壤为基质开展盆栽试验,在轻度镉污染（LC）土壤和重度镉污染（LG）上,分别设置空白对照（LCCK,LGCK）、单施木本生物炭（LCB,LGB）、单施多粘类芽孢杆菌（LCJ,LGJ）、木本生物炭 + 多粘类芽孢杆菌（LCBJ,LGBJ）八种处理,通过分析地上和地下紫苏生物量、紫苏各器官镉含量、土壤有效态镉含量、土壤pH等指标,解析木本生物炭和多年类芽孢杆菌对紫苏生长和镉吸收富集的影响特征。结果在重度镉污染土壤中,LGBJ处理对紫苏“促生”效果最显著,与LGCK相比,其地上部分和地下部分生物量分别增加48.26%和36.77%;在轻度镉污染土壤中,与LCCK相比,LCBJ处理地上和地下部分紫苏生物量分别增加14.15%和17.00%。在重度镉污染土壤中,土壤有效态镉含量表现为：LGBJ < LGB < LGCK < LGJ。LGBJ处理下土壤有效态镉含量比对照降低56.97%,地上和地下部分紫苏镉含量显著降低39.84%和33.03%。在轻度镉污染土壤中,LCBJ处理对土壤有效态镉含量和地上和地下部分紫苏镉含量的影响均不显著（P > 0.05）。此外,在不同程度镉污染条件下,木本生物炭与多粘类芽孢杆菌联合处理均显著提高土壤pH（P < 0.05）。相关性分析结果表明,土壤有效态镉的含量与土壤pH呈负相关关系,与地上和地下部分紫苏镉的含量均呈极显著正相关关系（P < 0.01）。结论在重度镉污染土壤中,木本生物炭与多粘类芽孢杆菌联合施用可通过调控土壤pH和土壤有效态镉的含量,降低紫苏对镉的吸收,从而缓解镉对紫苏生长抑制。     

侧胞芽孢杆菌发酵工艺的研究

侧胞芽孢杆菌是应用于微生物肥料的一种重要功能菌,采用正交试验筛选了侧胞芽孢杆菌的发酵培养基配方,并探讨了发酵工艺条件。结果表明,侧胞芽孢杆菌的摇瓶发酵最佳培养基为蔗糖3.0%、酵母膏0.8%、蛋白胨1.2%、MgSO40.075%、KH2PO40.25%、MnSO40.010%、CaCO30.8%最佳;培养条件为温度32.5℃、转速200 r/min、接种量2%以上、pH为7.6,发酵液中的所得菌浓度可达9×108个/mL。     

枯草芽孢杆菌液体发酵条件优化探究

通过单因素试验对枯草芽孢杆菌液体发酵培养基及发酵条件进行了优化,为实现该菌株的工业化生产提供数据参考.试验结果表明:该菌株培养基各组分的最佳配比为蛋白胨1％,麸皮:酵母提取物(3:2)为0.5％,氯化钠1％.最佳发酵培养条件为初始pH值6.0,培养温度为37℃,培养时间为24 h、装液量100 mL,接种量为4％,转速...     

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...     

多粘类芽孢杆菌JSa-9高产LI-F类抗菌脂肽突变株的选育

为了提高多粘类芽孢杆菌JSa-9产LI-F类抗菌脂肽的产量,本研究采用亚硝基胍(NTG)、60Co-γ射线和低能N+离子注入3种不同诱变方法,确定了NTG最佳诱变浓度为50μg·mL-1,60Co-γ射线最佳诱变剂量为200Gy;当低能N+离子注入能量为10keV,最佳注入时间为60 s,当注入能量为20keV,最佳注入时间为30 s。最终从300株突变株中筛选得到1株苯丙氨酸缺陷型菌株N1-37和1株组氨酸缺陷型菌株N2-27,均由NTG诱变获得。以金黄色葡萄球菌为指示菌进行抑菌试验,N1-37和N2-27抑菌圈直径比出发菌株JSa-9分别增加45.54%和32.35%。通过高效液相色谱确定LI-F类抗菌脂肽产量,结果表明,N1-37和N2-27产LI-F类抗菌脂肽的产量是原始菌株JSa-9的1.71倍和1.4倍,经连续传代10代,试验表明2菌株遗传稳定性良好,不仅可以应用于工业生产上,还可以作为亲本菌株进行细胞融合研究。     

巨大芽孢杆菌P1的解磷效果与发酵条件研究

以巨大芽孢杆菌P1为研究对象,利用钼锑抗比色法测定了菌株的解磷能力,采用单因子实验及正交实验优化了菌株的最佳发酵条件,并在10 L发酵罐上进行了发酵条件验证。巨大芽孢杆菌P1在蛋黄培养基上可产生明显的溶磷圈,溶磷圈直径和菌落直径的比值D/d=4.5。在卵磷脂液体培养基中培养4 d后,上清液中的有效磷含量为55.66 mg/mL,是对照的101.2倍,说明溶磷效果明显。单因子实验表明,最佳培养温度为32℃,培养时间为32 h,培养基初始pH为7.5。正交实验表明,最佳培养基组成为玉米粉20 g,黄豆粉10 g,K2HPO41.5 g,MgSO4.7H2O 1.5 g,CaCO31.5 g,H2O 1 000 mL,pH 7.5。方差分析表明,玉米粉、黄豆粉在α=0.05水平上对实验结果的影响存在显著性差异。10 L发酵罐发酵结果表明,巨大芽孢杆菌P1发酵32 h基本达到终点,菌数达到60.0×108cfu/mL,芽孢比率达90%以上。     

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。     

枯草芽孢杆菌发酵制备花生粕饲料条件优化

长期以来花生粕作为动物饲料得到广泛的应用,为提高其利用价值本文以热榨花生粕作为固体发酵培养基,以加水量、接种量、发酵时间、发酵温度、麸皮含量为变量进行单因素试验,采用响应面分析试验对枯草芽孢杆菌发酵制备花生粕饲料的条件进行优化。结果表明:枯草芽孢杆菌发酵制备花生粕饲料的最佳条件是花生粕18g、加水量20mL、接种量0.44g、发酵时间60h、发酵温度30℃。在此条件下,发酵后产物芽孢杆菌芽孢数较高。     

Pre-symbiotic and symbiotic interactions between Glomus intraradices and two Paenibacillus species isolated from AM propagules. In vitro and in vivo assays with soybean (AG043RG) as plant host

Two indole-producing Paenibacillus species, known to be associated with propagules of arbuscular mycorrhizal (AM) fungi, were examined for their mycorrhization helper bacteria activity at pre-symbiotic and symbiotic stages of the AM association. The effects were tested under in vitro and in vivo conditions using an axenically propagated strain of the AM fungus Glomus intraradices and Glycine max (soybean) as the plant host. The rates of spore germination and re-growth of intraradical mycelium were not affected by inoculation with Paenibacillus strains in spite of the variation of indole production measured in the bacterial supernatants. However, a significant promotion in pre-symbiotic mycelium development occurred after inoculation of both bacteria under in vitro conditions. The Paenibacillus rhizosphaerae strain TGX5E significantly increased the extraradical mycelium network, the rates of sporulation, and root colonization in the in vitro symbiotic association. These results were also observed in the rhizosphere of soybean plants grown under greenhouse conditions, when P. rhizosphaerae was co-inoculated with G. intraradices. However, soybean dry biomass production was not associated with the increased development and infectivity values of G. intraradices. Paenibacillus favisporus strain TG1R2 caused suppression of the parameters evaluated for G. intraradices during in vitro symbiotic stages, but not under in vivo conditions. The extraradical mycelium network produced and the colonization of soybean roots by G. intraradices were promoted compared to the control treatments. In addition, dual inoculation had a promoting effect on soybean biomass production. In summary, species of Paenibacillus associated with AM fungus structures in the soil, may have a promoting effect on short term pre-symbiotic mycelium development, and little impact on AM propagule germination. These findings could explain the associations found between some bacterial strains and AM fungus propagules.     

小麦-鹅观草易位系T7A/1Rk#1的选育与鉴定

将小麦-鹅观草del1Rk#1L二体添加系的花粉用10 Gy 60Co γ射线照射处理,给小麦中国春授粉,获得杂种。综合利用C-分带、GISH、顺次C带/45SrDNA-FISH和顺次GISH/45SrDNA-FISH等分子细胞遗传学技术在M2代筛选和鉴定出1个涉及小麦7A和鹅观草1Rk#1染色体的相互易位染色体系,并获得1Rk#1染色体的1个45SrDNA位标,该位标和其对应的红色GISH-带纹能够特异地识别1Rk#1染色体短臂。对M2代群体染色体组成分析和测交分析表明,两条易位染色体在后代中以共分离方式成对出现,且易位通过雌配子的传递率高于雄配子。综合2004、2005和2006 3年的赤霉病抗性鉴定结果表明：该易位系对赤霉病表现部分抗病,但抗性表现在不同年份、不同地点有差异。试验还证明花粉辐射是诱导小麦-外缘物种染色体易位的有效方法。     

Variability of communities and physiological characteristics between free-living bacteria and attached bacteria during the PAH biodegradation in a soil/water system

The biodegradation of polycyclic aromatic hydrocarbons (PAHs) via free-living and attached micro-organisms in soil/water systems was observed in order to examine the variability in the community dynamics and physiological profiles of the micro-organisms. As determined by fluorescence in situ hybridization (FISH), the Domain Bacteria, consisting of three phyla α-, β- and γ-Proteobacteria, reached 41.27–56.05% of all organisms in the soil/water system for PAH biodegradation. Among the free-living species, Proteobacteria, including Brevundimonas (Pseudomonas) diminuta, Caulobacter spp., Mycoplana bullata, Acidovorax spp. and Pseudomonas aeruginosa were found to be dominant—making up 93.51–99.80% of the population—and therefore seem to be associated with PAH biodegradation. Total plate count numbers and the count of Pseudomonas sp. present in the free-living population increased to between 10³ and 10⁶ CFU ml⁻¹ when clay with very low organic matter content was used as the matrix for PAH degradation. However, total plate count microbial numbers increased to only 10¹–10² CFU ml⁻¹ using natural soil from Taichung containing 1.883% organic matter. The soil organic content (SOM) seemed to affect the mass transfer of PAH in soil, leading to the difference in PAH biodegradation. Two different approaches, which included community-level physiological profiling (CLPP) and ectoenzymatic activities, were used to explain the functional diversity between free-living and attached bacteria. The free-living and attached bacterial communities from the clay system showed proportionately greater differences using CLPP. Relatively high levels of esterases, aminopeptidases and some specific glycolysis-gluconeogenesis enzymes gave an identifiable correlation with PAH biodegradation. The differences in bacterial composition, numbers and physiological characteristics show that free-living and attached micro-organisms may play different biochemical roles in PAH degradation in soil.     

Grazing of a common species of soil protozoa (Acanthamoeba castellanii) affects rhizosphere bacterial community composition and root architecture of rice (Oryza sativa L.)

We performed a controlled experiment with rice seedlings (Oryza sativa L.) growing in Petri dishes on homogeneous nutrient agar containing a simple rhizosphere food web consisting of a diverse bacterial community and a common soil protozoa, Acanthamoeba castellanii, as bacterial grazer. Presence of amoebae increased bacterial activity and significantly changed the community composition and spatial distribution of bacteria in the rhizosphere. In particular, Betaproteobacteria did benefit from protozoan grazing. We hypothesize that the changes in bacterial community composition affected the root architecture of rice plants. These effects on root architecture affect a fundamental aspect of plant productivity. Root systems in presence of protozoa were characterized by high numbers of elongated (L-type) laterals, those laterals that are a prerequisite for the construction of branched root systems. This was in sharp contrast to root system development in absence of protozoa, where high numbers of lateral root primordia and short (S-type) laterals occurred which did not grow out of the rhizosphere region of the axile root. As a consequence of nutrient release from grazed bacteria and changes in root architecture, the nitrogen content of rice shoots increased by 45% in presence of protozoa. Our study illustrates that interactions over three trophic levels, i.e. between plants, bacteria and protozoa significantly modify root architecture and nutrient uptake by plants.     

污水处理反硝化除磷-诱导结晶磷回收工艺中除磷微生物特性

为探究反硝化除磷-诱导结晶磷回收工艺中缺氧池污泥释磷、吸磷以及微生物特征,利用荧光原位杂交（fluorescence in situ hybridization,FISH）技术、电子扫描显微镜（scanning electron microscope,SEM）观察了微生物的数量、分布和形态;通过批次试验考察了污泥在厌氧/好氧和厌氧/缺氧2种模式下的释磷和吸磷特征。结果表明：该双污泥系统缺氧池中聚磷菌占总细菌比例的69.7%,明显高于单污泥系统中富集的聚磷菌比例,污泥中的微生物多呈杆状;厌氧/好氧、厌氧/缺氧模式下单位污泥浓度（mixed liquor suspended solids,MLSS）总吸磷量（以PO43--P计）分别为22.84、18.60 mg/g,反硝化聚磷菌（denitrifying polyphosphate-accumulating organisms,DPAO）占聚磷菌（polyphosphate-accumulating organisms,PAO）的比例为81.44%,表明在长期的厌氧/缺氧运行条件下可以富集到以硝酸盐为电子受体的反硝化聚磷菌,同时还存在着仅以氧气为电子受体的聚磷菌;通过pH值和氧化还原电位（oxidation reduction potential,ORP）的实时监测可以快速地了解污水生物处理系统中各类反应的进程,对调控工艺参数有着重要的意义。综上所述,为保证污水生物处理工艺的正常稳定运行,将微生物分析与常规的化学参数分析结合起来考察将是未来发展的必然趋势。     

巴西橡胶树4个环锌指蛋白基因（HbRZF）的物理定位

本文利用原位PCR技术和荧光原位杂交技术,对巴西橡胶树4个环锌指蛋白基因（HbRZF）在染色体的位置进行了物理定位分析。结果表明：用原位PCR技术检测到的HbRZF1和HbRZF3扩增信号分别定位于巴西橡胶热研7-33-97品种的第6号和第5号染色体长臂上,信号距着丝粒平均百分距离分别是45.76±3.18和66.33±0.75,信号检出率分别为28.79%和36.70%。用荧光原位杂交技术检测到的HbRZF2和HbRZF4探针信号分别位于第3号和7号染色体长臂上,信号距着丝粒平均百分距离分别为22.25±1.02和40.64±1.44,两种信号同时检出的机率为12.18%。本研究还对这些基因与其他定位的基因之间的连锁关系进行了讨论。     

Non-symbiotic bacterial diazotrophs in crop-farming systems: can their potential for plant growth promotion be better exploited?

Biological N₂ fixation (BNF) by associative diazotrophic bacteria is a spontaneous process where soil N is limited and adequate C sources are available. Yet the ability of these bacteria to contribute to yields in crops is only partly a result of BNF. A range of diazotrophic plant growth-promoting rhizobacteria participate in interactions with C₃ and C₄ crop plants (e.g. rice, wheat, maize, sugarcane and cotton), significantly increasing their vegetative growth and grain yield. We review the potential of these bacteria to contribute to yield increases in a range of field crops and outline possible strategies to obtain such yield increases more reliably. The mechanisms involved have a significant plant growth-promoting potential, retaining more soil organic-N and other nutrients in the plant-soil system, thus reducing the need for fertiliser N and P. Economic and environmental benefits can include increased income from high yields, reduced fertiliser costs and reduced emission of the greenhouse gas, N₂O (with more than 300 times the global warming effect of CO₂), as well as reduced leaching of NO₃⁻-N to ground water. Obtaining maximum benefits on farms from diazotrophic, plant growth promoting biofertilisers will require a systematic strategy designed to fully utilise all these beneficial factors, allowing crop yields to be maintained or even increased while fertiliser applications are reduced.     

Biological control of damping-off caused by Rhizoctonia solani using chitinase-producing Paenibacillus illinoisensis KJA-424

A bacterium having strong chitinolytic activity was isolated from a coastal soil in Korea and identified as Paenibacillus illinoisensis KJA-424 on the basis of the nucleotide sequence of a 16S rRNA gene. By activity staining after SDS-PAGE, three major chitinase bands with chitinolytic activity, approximate molecular weight of 63, 54 and 38 kDa were detected. On co-culture Rhizoctonia solani with KJA-424, abnormal swelling and deformation of R. solani hyphae were observed, where the release of N-acetyl-d-glucosamine was detected. The bacterium suppressed the symptom of damping-off cucumber seedlings caused by R. solani, in greenhouse trial.