鲟源病原性嗜水气单胞菌拮抗芽孢杆菌的鉴定及其生物学特性

从养殖池污泥中分离筛选了1株优良的鲟源嗜水气单胞菌拮抗芽孢杆菌G1,其对鲟源嗜水气单胞菌S1产生的抑菌圈直径为18.50 mm。通过API50CH细菌鉴定系统以及16S rRNA序列分析法,菌株G1被鉴定为解淀粉芽孢杆菌(Bacillus amyloliquefaciens),GenBank登录号HM245965.1,其16S rRNA序列与基因库中芽孢杆菌属菌株的16S rRNA序列有99%100%的同源性,而且与解淀粉芽孢杆菌Ba-74501(GenBank登录号:DQ422953.1)的亲缘关系最近。菌株G1的最适生长pH值为7,最适生长温度为30°C,其在30°C、200 r/min条件下的生长曲线为:0 6 h为生长延迟期,6 54 h为对数生长期,54 90 h为稳定期,90 h以后为衰亡期。此外,菌株G1对其他实验选用的病原性嗜水气单胞菌也表现出良好的拮抗活性。本实验结果有利于填补嗜水气单胞菌拮抗菌在分类地位、生物学特性等方面的不足,为鲟鱼嗜水气单胞菌病的生物防控提供科学资料。     

西伯利亚鲟源嗜水气单胞菌致病菌的分离及其全菌苗的免疫效果

从患细菌性败血症的西伯利亚鲟(Acipenser baerii)的体内分离到一株致病菌株X1,其对西伯利亚鲟的半数致死浓度(LC50)为5.62×105 cfu/ml,具有较强毒力;经ATB细菌鉴定仪生理生化鉴定和16SrDNA序列分析,菌株X1为嗜水气单胞菌(Aeromonas hydrophila);其系统发育分析表明,菌株X1与嗜水气单胞菌ATCC35654(登录号:X74676.1)的亲缘关系最近,其同源性为99%.用0.30%福尔马林灭活,将菌株X1制成灭活全菌苗,对西伯利亚鲟进行注射免疫.研究结果表明,嗜水气单胞菌X1全菌苗能够明显提高西伯利亚鲟的血清抗体水平及总蛋白、免疫球蛋白、溶菌酶含量,而且在嗜水气单胞菌X1全菌苗中加入弗氏不完全佐剂,有利于进一步增强西伯利亚鲟血清抗体水平及总蛋白、免疫球蛋白、溶菌酶含量.此外,嗜水气单胞菌X1全菌苗对西伯利亚鲟抗嗜水气单胞菌X1人工感染也具有较好的免疫保护作用,其对西伯利亚鲟的免疫保护率为50%,而且在嗜水气单胞菌X1全菌苗中加入弗氏不完全佐剂,嗜水气单胞菌X1全菌苗对西伯利亚鲟抗嗜水气单胞菌X1人工感染的免疫保护作用更好,其对西伯利亚鲟的免疫保护率为70%.因此,将嗜水气单胞菌X1全菌苗用于西伯利亚鲟细菌性败血症的防治具有广阔的发展前景.     

连翘提取物对嗜水气单胞菌群体感应系统的影响

【背景】传统抑菌剂的大量使用导致细菌产生多重耐药性与抗性,而基于细菌群体感应靶点调控的新型抑菌剂可缓解细菌耐药性与抗性,是未来抑菌剂的发展方向之一。【目的】研究连翘(Forsythiasuspensa)提取物对嗜水气单胞菌(Aeromonashydrophila)群体感应系统的影响及可能的作用机制,为新型抑菌剂的开发提供理论依据。【方法】以紫色杆菌(Chromobacterium violaceum)CV026为报告菌株,以嗜水气单胞菌为供试菌株,采用倍比稀释法测定连翘提取物对2种菌的最小抑菌浓度(minimal inhibitory concentration,MIC),通过微量法测定提取物对嗜水气单胞菌生长、群集运动及蛋白酶活性的影响,利用高效液相色谱串联质谱法分析提取物中的主要成分,采用分子对接模拟探究提取物对嗜水气单胞菌群体感应系统的作用机制。【结果】连翘提取物对紫色杆菌CV026和嗜水气单胞菌的MIC均为16.00mg/mL。在亚抑菌浓度下,连翘提取物处理显著抑制了CV026紫色菌素的产生,最大抑制率高达56.30%。经8.00mg/mL连翘提取物处理后,嗜水气单胞菌的群集运...     

嗜水气单胞菌HBNUAh01 外膜蛋白A 基因在烟草叶片细胞中的瞬时表达

【目的】从嗜水气单胞菌(Aeromonas hydrophila)HBNUAh01中克隆外膜蛋白A(outer membrane proteinA,ompA)基因并在烟草(Nicotiana tabacum)叶片细胞中瞬时表达该蛋白。【方法】以嗜水气单胞菌HBNUAh01为模板进行嗜水气单胞菌外膜蛋白A(AhompA)基因片段的PCR扩增,并将其克隆到pEASY-Blunt Simple载体中以进行测序。测序正确的AhompA基因序列与含有黄色荧光蛋白(yellow fluorescentprotein,YFP)基因的表达载体pCAMBIA1300构建重组表达载体。将该重组表达载体转化到农杆菌(Agrobacterium tumefaciens)GV3101感受态细胞中,随后用阳性转化子转染烟草叶片细胞。使用激光扫描共聚焦成像系统(Confocal Laser Scanning Microscope)检测观察融合表达AhompA基因的黄色荧光蛋白并采用RT-PCR检测AhompA基因在烟草叶片中的转录情况。【结果】从嗜水气单胞菌HBNUAh01中克隆出大小为1032 bp的AhompA基因序列,并在烟草叶片中成功表达AhompA和YFP的融合蛋白。【结论】AhompA基因在烟草叶片细胞中的成功表达为进一步研究利用植物疫苗防治嗜水气单胞菌引起的水产动物疾病奠定了基础。     

一株引起马来甜龙竹组培污染内生菌的分离与鉴定

【目的】对一株引起马来甜龙竹组培污染内生菌的分离与鉴定。【方法】采用改良的NA培养基分离纯化菌株,并通过菌体的形态结构观察、生理生化试验及其16SrDNA序列同源性分析对其进行鉴定。【结果】菌株SWFU01的形态特征及生理生化试验结果与解淀粉芽孢杆菌[Bacillus amyloliquefaciens(Fukumoto)Priest et al.]的描述基本相同;16S rDNA序列分析表明,该菌株与解淀粉芽孢杆菌JS在同一系统发育分支,其同源性为99.28%。【结论】综合形态学特征、生理生化特征以及16S rDNA序列分析的研究结果,菌株SWFU01被鉴定为解淀粉芽孢杆菌。     

喷雾干燥制备高纯α-亚麻酸微胶囊研究

本文采用喷雾干燥法制备高纯α-亚麻酸为芯材、亚麻籽胶为壁材的微胶囊,并以微胶囊化效率和含油率为指标,考察了制备工艺.结果表明,最佳微胶囊原料配方为:芯材与壁材的比例为(m/m)3∶2,料液浓度为5％,进料温度为20℃;最佳喷雾干燥工艺条件:进风温度为180℃,出风温度为80℃,雾化器转速21000 rpm,进料速度为42.01 mL/min.在此工艺条件下亚麻酸的微胶囊化效率为96.18％,含油率为60.09％.     

正交法优化保加利亚乳杆菌NQ2508微囊制备工艺

目的制备保加利亚乳杆菌NQ2508双层微胶囊,并考察其包埋产率和耐胃酸能力。方法以保加利亚乳杆菌NQ2508改性淀粉微胶囊为研究对象,以聚丙烯酸树脂为包衣材料,采用流化床底喷工艺制备微胶囊,通过正交试验考察进风温度、雾化压力、进风风量、包衣增重4个因素对微胶囊化的影响。结果最佳工艺条件为进风温度50℃、雾化压力2.0bar、进风风量35m3/h、包衣增重30%,在该工艺条件下制得的微胶囊包埋产率为50.2%,微胶囊经人工胃酸处理后活菌存活率为39.2%。结论工艺优化后制得保加利亚乳杆菌NQ2508双层微胶囊的包埋产率和耐酸能力均较高。     

嗜水气单胞菌J-1株弹性蛋白酶的表达、纯化及特性分析

摘要：【目的】表达、纯化嗜水气单胞菌J-1株弹性蛋白酶,并对弹性蛋白酶的性质进行分析。【方法】以pET-32a为表达载体将弹性蛋白酶基因ahyB转化至大肠杆菌BL21菌株中进行诱导表达,表达重组酶用His TaqNi2+亲和层析柱纯化并用6 mol/L盐酸胍进行复性;利用硫酸铵分级沉淀、阴离子交换层析和分子筛层析对嗜水气单胞菌培养上清液中的弹性蛋白酶进行纯化。将【结果】从嗜水气单胞菌培养上清液中获得的弹性蛋白酶原酶的最适pH 为8.5,而表达重组酶为 10.0;对热的稳定性,原酶高于表达酶。两种形式酶的性     

CP7抗菌蛋白对嗜水气单胞菌的抑杀作用机理

[目的]研究多粘类芽孢杆菌(Paenibacillus polymyxa) CP7菌株的抗菌蛋白(CP7ACP)对嗜水气单胞菌的抑杀作用机理,为防治嗜水气单胞菌引起的鱼病提供新的潜在天然药物.[方法]采用抑菌试验、钼锑抗比色法和紫外光谱法研究其对嗜水气单胞菌S12菌株生长、磷泄漏和生物大分子的影响,并利用扫描电镜和透射电镜观察了嗜水气单胞菌细胞结构遭受的破坏作用.[结果]CP7ACP对嗜水气单胞菌的抑菌圈直径约8.1 mm,最小抑菌浓度(MIC)与最小杀菌浓度(MBC)分别为原液浓度的1/8和1/4;嗜水气单胞菌受CP7ACP处理后,电镜观察发现其细胞壁、细胞膜、细胞器以及菌体均受到不同程度的破坏,胞内的生物大分子和磷泄漏明显,基因组DNA发生增色效应.[结论]CP7ACP抑制嗜水气单胞菌生长,可用于防治嗜水气单胞菌引起的鱼病.     

抗病促生复合芽孢杆菌水分散粒剂的研制与应用

【背景】乳油、可湿性粉剂和粉剂等生物制剂含有苯类有机溶剂及粉尘,会对环境造成污染,而水分散粒剂具有环境友好性、附加值高、市场潜力大等优点,被认为是最具发展前景的剂型之一,然而关于复合芽孢杆菌水分散颗粒的研究却很少。【目的】利用解淀粉芽孢杆菌BZ6-1和短小芽孢杆菌SC-12研制成一种复合芽孢杆菌水分散粒剂。【方法】通过生物相容性实验,研究不同载体和助剂对两种芽孢杆菌孢子的影响,以筛选出最佳载体和添加剂。通过质量检测实验,研究不同筛孔直径、干燥温度、干燥时间对水分散性颗粒质量的影响,以优化制粒条件。在辣椒定植后,使用不同剂量的水分散粒剂进行田间辣椒试验。【结果】复合芽孢杆菌水分散粒剂最佳配方：润湿剂4%十二烷基硫酸钠,分散剂6%羧甲基纤维素钠,崩解剂4%硫酸铵,粘结剂4%聚乙二醇,载体82%硅藻土;最佳造粒条件为：筛孔粒径0.8 mm,烘干温度40 °C,烘干时间45 min。研制出的复合芽孢杆菌水分散粒剂含菌量为2.52×108 cfu/g,悬浮率为79.3%,pH 6.8,水分含量为4.5%,湿润时间为19.6 s,崩解时间为86.4 s,颗粒强度适中,符合水分散粒剂国家标准。【结论】研制出的复合芽孢杆菌水分散粒剂能够有效防治辣椒青枯病,并提高辣椒的产量和品质,推荐复合芽孢杆菌水分散粒剂最适用量为3.0 kg/hm2。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Specificity of action of piperidylcholine derivatives as substrates of cholinesterases of various origin

The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

The mechanism of hatching of eggs of Haemonchus contortus

Fluid collected from hatching eggs of Haemonchus contortus contained a lipase which hydrolysed 2-naphthyl laurate (about 0·7 μmol naphthol freed /h/10⁶ eggs). The fluid also hydrolysed l-leucinamide (about 2·3 μmol leucine freed/h/10⁶ eggs). The fluid when added to normal or heated eggs caused ‘hatching’. ‘Hatching’ also occurred in exsheathing fluid from infective juveniles and in a preparation of pancreatic lipase containing leucine aminopeptidase. A purified mammalian leucine aminopeptidase in combination with several different lipases did not attack egg shells.The ‘spontaneous’ hatching of eggs of H. contortus was strongly inhibited by 1,10-phenanthroline, 10^?3M, and this inhibition was reversed by Zn²⁺. However, the inhibition of ‘hatching’ of eggs in externally applied hatching fluid, or the hydrolysis of leucinamide in hatching fluid was generally less marked.