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1、琥珀酸產(chǎn)生菌的分離鑒定、誘變選育及發(fā)酵條件優(yōu)化摘要細(xì)菌發(fā)酵生產(chǎn)琥珀酸成本低廉、對(duì)環(huán)境污染少。由于其生產(chǎn)原料可再生,并能吸收利用溫室氣體C02,使之成為近年來國(guó)內(nèi)外生物質(zhì)能源轉(zhuǎn)化的研究熱點(diǎn)。+本研究通過采用選擇性較強(qiáng)的富集培養(yǎng)和快速準(zhǔn)確篩選程序,從牛瘤胃中分離出適于淀粉質(zhì)原料的琥珀酸產(chǎn)生菌,并進(jìn)行相關(guān)的生理生化鑒定;通過紫外照射誘變育種得到琥珀酸高產(chǎn)突變株,優(yōu)化培養(yǎng)基組成并確定最適發(fā)酵培養(yǎng)條件。主要研究結(jié)論如下:1.在富集培養(yǎng)中添加莫能菌素和富馬酸鈉,經(jīng)溴甲酚綠變色平板快速檢出500株產(chǎn)酸菌株。菌株發(fā)酵后經(jīng)TLC初篩和改進(jìn)后的HPCE方法復(fù)篩檢測(cè),得到6株優(yōu)良產(chǎn)
2、酸菌株,其中B-15菌株產(chǎn)琥珀酸11.5g.L~,副產(chǎn)物甲酸4.659·L.1,乙酸6.25g·L~,該菌株琥珀酸產(chǎn)量最高。菌株B.15經(jīng)生理生化鑒定后,初步確定其為放線孝T菌屬(Actinobac趔凇sp.)。2.以B.15為出發(fā)菌株,通過紫外照射誘變,依次采用溴甲酚綠平板、氟乙酸平板和丙烯醇平板對(duì)菌株進(jìn)行定向選育,得到的突變株FB.4發(fā)酵產(chǎn)琥珀酸19.909‘L-】,副產(chǎn)物乙醇7.55g·L-J,甲酸2.05g'L一,乙酸4.85g·L一,其琥珀酸產(chǎn)量較原始菌株提高70%。3.對(duì)突變株FB一4進(jìn)行發(fā)酵試驗(yàn)的結(jié)果表明,最佳發(fā)酵培養(yǎng)基組成為,葡萄糖509'L一
3、,酵母提取物109·L.1,玉米漿5g-L~,K2HP043g-L~,MgCl2·6H200.4g'L~,CaCl20.3g·L一,NaCl0.5g'L~,MgC0315g.L一,復(fù)合氮源對(duì)菌株發(fā)酵影響較大;搖瓶最適發(fā)酵培養(yǎng)條件為,溫度37"C,接種量5%,轉(zhuǎn)速100r.min~,厭氧發(fā)酵氣室控制條件為,40%C02,5%I-12。在上述條件下初始pH7.0,發(fā)酵48h,琥珀酸產(chǎn)量達(dá)24g·U1。關(guān)鍵詞:琥珀酸菌株分離鑒定誘變育種發(fā)酵Isolation,Identification,MutationBreedingandFermentationConditio
4、nOptimizationofaStrainforProducingSuccinicacidABSTRACTTherearesomeadvantagesinsuccinicacidfermentationbybacteria,suchaslowprocessingCOStandlittlepollutionforenvironment.BecauseofusingrenewableagricultureresourcesandgreenhousegasC02,theresearchforsuccinicacidfermentationhasbecometheh
5、otspotofbioconversionresearchathomeandabroadinlastyears.Inhighselectivityenrichmentculturingprocessandrapidscreeningprocedure.thesuecinicacidproducerswimstarchnessandsaccharidewereisolatedfrombovinerumen.Aftertherelatedphysiologicalandbiochemicalreactionidentification,theparentstrai
6、nwasirradiatedbyUV.Duringsomescreeningplatesthemutantslrainswereobtainedwithhi【曲yieldofsuccinieacid.Andthen,theculturemediumingredientandfermentationconditionwereoptimized.Themainresultswereasfollowing:1.Themonensinandfumaratesodiumwereaddedinenrichmentcultureforselectiveculturingmo
7、stofbacteria,whichwouldproducesuccinicacidfrombovineruminalcontents.Fivehundredstrainsproducingorganicacidwereisolatedwithyellowhoopasselectivemarkpresentedinthebromocresolgreenmedium.AftersimplefermentationsixstainswithhighyieldwereselectedbyTLCpreliminaryscreeningandtheimprovedHPC
8、Esecondaryscreening