降血尿酸益生菌株的筛选和降血尿酸机理的探索

【背景】高尿酸血症是人体内血尿酸含量显著高于正常水平的代谢性疾病,利用益生菌降解食物中外源性嘌呤类成分成为治疗高尿酸血症的新方法。【目的】筛选具有降低血尿酸作用的益生菌,并探索其作用机制。【方法】利用HPLC从多株实验菌株中筛选降解核苷酸(腺苷酸、鸟苷酸)、核苷(腺苷、鸟苷)、嘌呤(黄嘌呤、次黄嘌呤、鸟嘌呤)、尿酸能力最强的益生菌。首次利用质谱定性与定量检测菌株降解核苷与核苷酸过程中代谢物的变化,结合菌株对高尿酸血症模型大鼠血尿酸水平的影响,初步探索其降低血尿酸的机理。【结果】首次筛选出具有较强降解核苷酸与核苷能力的干酪乳杆菌ZM15(CGMCC No.13980),高尿酸血症模型大鼠验证其具有降低血尿酸的作用。结果显示菌株ZM15在胞内降解核苷酸、核苷后,胞内、外均测到鸟嘌呤、黄嘌呤、次黄嘌呤,且胞内3种嘌呤含量显著高于正常菌体内含量(P0.01),尿酸和尿囊素在胞内、外均未发现。【结论】干酪乳杆菌ZM15具有较强的降解核苷酸、核苷的能力,推测其主要通过与肠道上皮细胞竞争吸收核苷酸与核苷,从而对高尿酸血症模型大鼠具有降血尿酸作用。     

降解尿酸乳酸菌复合菌系的筛选与菌株组合提升降解效果

【背景】高尿酸症由血液中尿酸含量明显升高而导致,利用乳酸菌对人体的益生作用缓解高尿酸血症越来越受到关注。【目的】获得具有降解尿酸能力的乳酸菌复合菌系与纯培养菌株。【方法】以泡菜为样品来源,以尿酸为底物,采用MRS培养基筛选降解尿酸的乳酸菌复合菌系,通过高效液相色谱法测定复合菌系对尿酸的降解能力。【结果】得到一组乳酸菌复合菌系,当培养温度为37 °C、pH值为6.20、静置培养72 h后复合菌系对尿酸的降解率为12.08%;通过优化培养条件,当该菌系在以牛肉膏为单一氮源、初始pH值为5.00、温度为35 °C的条件下培养72 h,尿酸降解率上升至17.19%,降解率比优化前提高了42.3%;从该菌系中分离出两株具有尿酸降解能力的菌株UA-1与UA-2,它们的尿酸降解率分别为10.85%和8.65%;通过形态学观察和16S rRNA基因序列分析,经鉴定两株菌均为布氏乳杆菌(Lactobacillus buchneri)。将两株单菌组合降解尿酸试验发现,UA-1与UA-2比例为2:1的尿酸降解率为20.2%,比原复合菌系的降解能力提高了67.22%。【结论】研究证明了乳酸菌复合菌系对尿酸的降解能力优于单个菌株,为后续利用乳酸菌复合菌系应用提供了数据支持。     

鄂尔多斯地区自然发酵苦菜中优良特性乳酸菌的筛选

【背景】鄂尔多斯地区传统自然发酵苦菜风味和作用独特,但目前尚无关于发酵苦菜中乳酸菌种类及其生物学特性研究的报道。【目的】获得适用于工业化生产特性优良的乳酸菌。【方法】通过测定总酸度筛选高产酸菌株,并进行形态学鉴定、生理生化特性研究,以及16S rRNA基因片段分析。【结果】经鉴定5株高产酸的菌株均为植物乳杆菌,生长温度范围宽,并且具有耐酸、耐碱、耐盐、耐热的特性。【结论】试验菌株具有优良的生理特性和潜在的益生特性,可用于食品工业的生产。     

耐受微酸性次氯酸水乳酸菌的分离鉴定、耐受特性及益生特性

【背景】次氯酸水具有杀菌性，当其作为饮用水可能会对畜禽肠道内有益菌造成负面影响。【目的】筛选出具有耐受微酸性次氯酸水(slightly acidic hypochlorous acid water, SAHW)能力的乳酸菌并研究其益生特性。【方法】从内蒙古地区传统自然发酵制品中分离筛选出8株乳酸菌菌株，经16SrRNA基因测序进行鉴定。进一步通过耐受SAHW、耐酸、耐胆盐、疏水性及自凝聚能力试验进行耐受特性和益生特性研究。【结果】菌株MBH3-2为副干酪乳杆菌，其经过质量浓度为20mg/L的SAHW处理2h，菌落对数值仅下降0.3lg(CFU/mL)，存活率为50.10%；而且在酸性(pH 2.0、2.5和3.0)、胆盐环境下均可存活；疏水率达62.12%，属于高度疏水性；自凝聚能力在2 h达到97.29%。【结论】最终确定一株具有优良耐受SAHW及基本满足作为微生态制剂要求的菌株，MBH3-2具有作为新型微生态制剂菌株的潜力。     

新生婴儿源植物乳杆菌HLPL03的环境耐受性及其代谢功能低聚糖的生物学活性

【目的】解析健康新生婴儿胎便中植物乳杆菌HLPL03的益生功能,评价其环境耐受性及代谢功能低聚糖的生物学活性。【方法】通过耐受胃肠道条件、过氧化氢和抗生素试验,评估植物乳杆菌HLPL03对极端环境的耐受性;利用改良培养基,评价植物乳杆菌HLPL03代谢功能低聚糖的能力;同时,探究功能低聚糖对植物乳杆菌HLPL03抑菌活性、疏水性和黏附能力的影响。【结果】植物乳杆菌HLPL03在pH 2.5条件下培养3 h后,活菌数仍在10⁴ CFU/mL以上;在0.30%胆盐中培养6 h后,活菌数接近10⁷ CFU/mL;在1.0 mmol/L H₂O₂强氧化剂条件下培养6 h,活菌数显著升高(P<0.001);除低聚木糖外,植物乳杆菌HLPL03能代谢多种功能低聚糖,并对常见食源性致病菌具有较强的抑制能力;棉子糖是改善植物乳杆菌HLPL03生物学活性的最佳低聚糖,其能提高菌株表面疏水性达36.1%,且促进菌株在Caco-2细胞上的黏附率由16.78%提高至42.11%。【结论】健康新生婴儿源植物乳杆菌HLPL03具有良好的抗环境胁迫能力,且其生物学活性能被棉子糖等功能低聚糖有效促进,可作为特色乳酸菌进行研究和开发。     

降血尿酸乳酸菌筛选及其对高尿酸血症模型大鼠作用研究

目的 提出利用具特殊活性乳酸菌来预防、治疗高尿酸血症方法,筛选具有较高降血尿酸活性的乳酸菌.方法 基于RP-HPLC方法,通过检测培养液培养前后肌苷、鸟苷含量变化,筛选出具有最快核苷分解速率的乳酸菌株作为候选菌株.并将其施用于高尿酸血症模型大鼠,观察对模型大鼠血尿酸含量影响.结果 获得具有最佳核苷分解速率的菌株DM9218.动物实验结果表明DM9218干预组的血尿酸浓度(219.25±21.98) μmol/L明显低于模型组(311.75±27.07) μmol/L(P＜0.05).结论 菌株DM9218具有最快的核苷分解速率,对高尿酸血症大鼠具有明显的降血尿酸作用.菌株DM9218为植物乳杆菌(Lactobacillus plantarum).     

猪源乳酸菌的分离、鉴定及其生物学特性

【目的】将分离自猪肠道粘膜、食糜和粪便的乳酸菌,通过产乳酸能力、生长性能、耐酸和耐胆盐性能及抑菌能力评价,筛选适应养猪生产的潜在益生特性的菌株。【方法】共分离获得155株乳酸菌纯菌株,从中筛选出4株产酸能力较强的乳酸菌,结合生理生化试验及细菌16S rRNA测序鉴定其种属,评价候选乳酸菌的生长情况、耐酸、耐胆盐及抑菌特性。【结果】综合变色时间(8 h)、pH值(3.9)和乳酸含量(100 mmol/L),筛选出4株(L45、L47、L63和L79)候选菌株,经鉴定依次为罗伊氏乳杆菌、植物乳杆菌、约氏乳杆菌和粪肠球菌。该4株乳酸菌均可在体外快速生长;L47和L79能够耐受pH 2.5的酸性环境,L47能够耐受0.5%胆盐环境;各乳酸菌上清液与指示菌共培养,发现对E coli K88和沙门氏菌均产生了抑制作用,其中L47上清液对指示菌的抑制作用较强。【结论】L47具有较好的产酸性能与生长性能、可耐受猪胃酸和肠道胆盐环境,对E.coli K88和沙门氏菌具有较好的抑制作用,说明该乳酸菌具有潜在的益生特性。     

胆盐水解酶产生菌的筛选及其益生潜力研究

目的从健康仔猪肠道及粪便中筛选具有胆盐水解酶活性的优良益生乳杆菌菌株,并对筛选菌株的体外、体内益生潜力进行初步探讨。方法用MRS培养基分别从仔猪新鲜粪便和小肠黏膜分离培养乳酸菌,用筛选鉴别培养基筛选阳性菌株,研究菌株的抗逆能力、黏附特性以及体内益生活性。结果从粪便和小肠黏膜共得到乳酸菌388株和97株,其中胆盐水解酶阳性菌株分别为291株(75%)和86株(89%)。选择5株胆盐水解酶活性最强、能水解游离胆酸的菌株,研究菌株的抗逆能力、黏附特性以及体内益生活性,并对最终选育得到的菌株进行生理生化及16S rRNA分子鉴定,发现菌株罗伊乳杆菌G22-2能耐受pH 3.0的酸度、1.0%的胆盐浓度,在小肠上皮细胞上的黏附效率超过15个以上;通过大鼠体内实验,筛选出的菌株G22-2对大鼠无毒无害,并能显著改善血脂水平。结论罗伊乳杆菌G22-2符合益生菌的要求,可以作为产胆盐水解酶的益生乳杆菌优良的候选菌株。     

大曲来源淀粉利用型乳酸菌的筛选及其淀粉利用特性

【背景】乳酸菌是面包、馒头等发酵食品中的重要功能微生物,对改善质地和风味均具有重要作用。淀粉利用能力高的乳酸菌,因其能够在生面粉中更好地定殖而具有重要的应用价值。【目的】筛选获得淀粉水解型乳酸菌并研究其淀粉利用特性。【方法】以浓香型白酒大曲为筛选源,采用淀粉基质碳源对大曲中乳酸菌进行定向富集,结合淀粉发酵能力筛选高淀粉利用能力菌株,并对筛选得到的优良菌株展开淀粉酶表达及其酶活力研究。【结果】以贮存3-6个月的大曲为优秀筛选源,以生面糊传代富集方法可较快筛选出具有良好淀粉利用能力的乳杆菌,主要物种为植物乳杆菌和类食品乳杆菌。对其中一株具有淀粉利用能力的类食品乳杆菌LBM12001的淀粉水解特征和淀粉酶活力展开研究,该菌株淀粉水解能力达10 g/L,并且其在面糊中具有良好的定殖能力;酶活力测定表明,其α-淀粉酶和麦芽糖淀粉酶为胞外酶;麦芽糖淀粉酶水解淀粉的最适pH值为3.5,比酶活为1 240 U/mg。【结论】建立起从我国传统白酒发酵大曲中高效筛选淀粉水解型乳酸菌的富集筛选方法,以及菌株的水解能力评价方法,获得的胞外麦芽糖淀粉酶分泌型乳杆菌在酸面团、馒头等需进行生面粉发酵食品的生产中具有重要应用前景。     

黄曲霉毒素B1脱毒菌株LAB-10的分离、鉴定及降解能力分析

【目的】从乳酸菌群含量丰富的动物肠道中筛选具有黄曲霉毒素B1(AFB1)脱毒应用前景的乳酸菌种。【方法】通过设计脱毒乳酸菌种特异性富集分离培养基,从肉鸡肠道粪便中筛选具有AFB1脱毒能力的微生物菌种,对脱毒菌种进行脱毒机理初步分析,并通过形态学、生理生化和系统发育学方法,鉴定脱毒菌种的系统分类学地位。【结果】脱毒菌株LAB-10经脱毒机理及降解能力测试分析,初步确定其AFB1的脱毒机理为生物降解作用,菌株LAB-10对14μg/L浓度AFB1在48 h的降解率为63.4%。形态学、生理生化及系统发育学研究结果表明,菌株LAB-10系统分类学地位为乳酸杆菌属的发酵乳杆菌。【结论】发酵乳杆菌LAB-10属于益生菌群,生物安全性高,该菌株在黄曲霉毒素降解测试培养基中显示出显著的AFB1降解能力,具有一定的应用潜力。     

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.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

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。     

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.     

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.     

医疗机构合理用药评价模型的构建研究

目的 针对医疗机构的合理用药水平进行评价研究。方法 根据医疗机构合理用药的具体要求,构建医疗机构合理用药评价指标体系,采用基于模糊群决策的方法和多指标评价分析法构建医疗机构合理用药评价模型。结果 构建了基于模糊群决策的医疗机构合理用药评价模型,并通过实例分析证明了评价模型的可行性。结论 建立的基于模糊群决策的医疗机构合理用药评价模型能够对医疗机构的合理用药水平进行科学评价,为提高医疗机构合理用药水平奠定基础。     

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.