简介:将节杆菌和芽孢杆菌分别暴露于不同浓度的铅溶液中,并进行不同暴露时间的急性毒性试验。结果表明,500mg/kg的Pb(II)处理会使节杆菌中的细胞膜脂质过氧化产物——硫代巴比妥酸活性物质(TBARS)浓度显著降低(p〈0.05),而Pb(II)质量比变化对其他指标无显著影响(p〈0.05);铅处理会使芽孢杆菌中可溶性蛋白质量浓度、GSH质量浓度和超氧化物歧化酶(SOD)活性显著升高,而过氧化氢酶(CAT)活性显著降低(p〈0.05)。节杆菌的可溶性糖质量浓度、GSH质量浓度、SOD活性和TBARS浓度随暴露时间延长而显著增加;芽孢杆菌的可溶性糖质量浓度、GSH质量浓度和SOD活性随暴露时间延长而显著增加,TBARS浓度随暴露时间延长呈先增后减的变化趋势,CAT活性也表现出先增后降的变化趋势。铅处理对节杆菌和芽孢杆菌具有一定的胁迫作用,两种菌通过启动不同的抗性系统来抵抗外界胁迫。
简介:Inthispaper,thetotalsugarconcentration,proteinconcentration,lipidyieldandmorphologycharacteristicsofthealgaeresidueweredeterminedtoexplainthemechanismoflipidsextractionfromwetmicroalgaeScenedesmussp.byionicliquidassistedsubcriticalwater.Theresultsshowedsimilarvariationforthesugar,proteinandlipid.However,thetotalsugarwasmoresimilartolipidsyield,sotheresultsshowedthatthereactionbetweenionicliquidandcelluloseandhemicelluloseincellwallwasthemostimportantstepwhichdeterminedthelipidsextrationdirectly.Andthetotalsugarvariationmayberepresentingthelipidsyield.Forlaterlipidsextraction,wecandeterminethetotalsugarconcentrationtopredicttheextractionendproduct.
简介:ApotassiumsolubilizingbacterialstraindesignatedEGT,whichistolerantofhightemperature,wasisolatedfromanearthworm’sguttoobtainabacteriumthatcanweatherpotassium-bearingrockeffectivelythroughsolid-statefermentation.Molecularphylogenyand16SrRNAgenesequenceanalysisdemonstratedthebacterialstrainwasamemberoftheStreptomycesgenus.Toassessitspotentialtoreleasepotassiumfromsilicateminerals,thisstrainwasusedtodegradepotassium-bearingrockpowderbysolid-statefermentation.Afterfermentation,theamountofwater-solubleAl,FeandKofthesubstratewithactiveinoculumwashigherthanthoseofthecontrol,whichhadautoclavedinoculum,andthoseofthefreshsubstrate.Theresultindicatedthatthestrainhadtheabilitytoweatherpotassium-bearingrockandcouldbeusedasaninoculumintheproductionofpotassiumbio-fertilizer,duetoitspotassiumreleaseactivityfromrockandtolerancetohightemperature.
简介:Anewhexaketideacidesterifiedbythe17-hydroxylgroupof16,17-dihydroxycyclooctatin,namely17-[16,17-dihydroxycyclooctatinyl]-hexaketideester(1),amemberofthegroupofrarebacterialditerpeneswithafused5-8-5ringsystemwasisolatedfromstrainStreptomycessp.SR107.Thestructurewasdeterminedonthebasisofitsspectraldata(~1HNMR,~(13)CNMR,~1H-~1HCOSY,HSQC,HMBC,NOESY,IRandHR-ESI-MS).Theantibacterialactivitywasalsoevaluatedinthispaper.
简介:MachilusmaomingensisJinet唐,sp。nov。从始新世Maoming盆的Youganwo形成,华南,从叶建筑学和最优地保存的表皮的观点详细被学习。叶边缘是全部,主要脉络是羽状的;6~8根第二等的静脉是在场的,主要第二等的脉络是eucamptodromous。Stomata是paracytic并且发生在更低的外皮上。毛状体底是单细胞的。油房间在上面的外皮是在场的。描述的新石块种有Lauraceae的特征,特别地现存的类MachilusRumphius前Nees,并且它很类似于Machiluschinensis(本瑟姆)Hemsley,在南部的中国和越南散布的现存的种。因此,Machilusmaomingensissp。nov。被推断住在温暖、潮湿的气候。现在的石块的发现显示那Machilus在华南存在从至少始新世。
简介:ThepresentstudyinvestigatedthechemicalcompositionofethylacetateextractsfromanendophyticactinomyceteStreptomycessp.A0916anditshostPolygonumcuspidatum.Acomparativeanalysisoftheantimicrobialandantioxidantpropertiesoftheextractswasalsoconducted.32compoundsofP.cuspidatumand23compoundsofStreptomycessp.A0916wereisolatedandidentifiedbyGC/MS.Antimicrobialactivitiesoftheextractswereevaluatedusingeightmicrobialstrains(3Gram-positivebacteria,3Gram-negativebacteria,and2fungi).TheStreptomycessp.A0916extractsshowedawiderangeofantimicrobialactivitiesandpresentedgreaterantimicrobialeffectivenessthantheP.cuspidatumextracts.Theminimuminhibitoryconcentration(MIC)ofStreptomycessp.A0916extractsagainsttheampicillin-resistantstrainEnterococcusfaeciumSIIA843was32μg·mL-1.Furthermore,theextractshadgreaterantimicrobialeffectagainstGram-positivebacteriathanGram-negativebacteria.Finally,theantioxidantactivityoftheStreptomycessp.A0916extractswasequaltothatoftheP.cuspidatumextracts.Inconclusion,ourresultssuggestthattheendophyticactinomycetesofthemedicinalplantsareanimportantsourceofbioactivesubstances.
简介:MarinesedimentsampleswerecollectedfromthecoastalareasofSouthernIndia,particularlyinKanyakumariDistrict.Twenty-eightdifferentfungalstrainswereisolated.Thescreeningoffungifrommarinesedimentwasdonetoisolateapotentfungusthatcanproducebioactivecompoundsforbiomedicalapplications.OnlythreestrainsvizTrichodermagamsiiSP4,TalaromycesflavusSP5andAspergillusoryzaeSP6werescreenedforfurtherstudies.Theintracellularbioactivecompoundswereextractedusingsolventextractionmethod.Thecrudeextractsweretestedforitsanti-microbialandanti-cancerpropertiesandanalyticallycharacterizedusingGasChromatographyMassSpectrometry(GC-MS).Allthethreeextractswereactive,buttheextractfromT.flavusSP5wasfoundtobemoreactiveagainstvarioushumanpathogens,viz.,PseudomonasaeruginosaATCC27853(17.8±0.1),EscherichiacoliATCC52922(18.3±0.3),andCandidatropicalisATCC750(17.7±0.4).ItalsoexhibitedcytotoxicactivityagainstHEp2carcinomacelllinewiththeLC_(50)valueof25.7μg·mL~(-1).TheGC-MSdatarevealedthepresenceofeffectivebioactivecompounds.TheseresultsrevealedthattheextractfromisolatedfungusT.flavusSP5actedasapotentantimicrobial,antifungal,andanticanceragent,providingbasicinformationonthepotencyofmarinefungitowardsbiomedicalapplications;furtherinvestigationmayleadtothedevelopmentofnovelanticancerdrugs.
简介:摘要目的探讨PBL结合SP教学模式在护理教学中的应用及效果。方法从本院2014级护理专业随机选出两个班,分别作为实验组(45人)和对照组(44人),采用PBL结合SP教学模式对实验组进行护理实践教学,对照组采用PBL结合视频案例(videocases)授课,学期末进行期末理论和操作实践考试,并通过问卷调查表的形式对教学效果进行评估。结果实验组期末理论成绩和实践操作成绩均高于对照组(P<0.05),并且较PBL结合视频案例模式,PBL结合SPs教学优势更明显(P<0.05)。结论PBL+SPs教学法有利于护理实践教学、可以提高护生实践操作能力、增强护生综合素养。