共查询到18条相似文献,搜索用时 250 毫秒
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从土壤中分离得到一株藤黄灰链霉菌的新菌株 0 99,该菌株能产生一种具有显著抗肿瘤活性的新型抗生素AGPM。产生菌经紫外线单因子诱变、紫外线加氯化锂 (LiCl)复合诱变等两种诱变方式诱变处理后 ,其AGPM产量达到了 1 8 7μg/mL ,较出发菌株提高了 1 2倍。研究发现最优的紫外辐射时间和氯化锂浓度分别是 30~ 6 0s和 0 0 5~ 0 0 9mol/L ,并且由于氯化锂的协同效应 ,菌株在经氯化锂处理后 ,对紫外线的敏感性明显增强了。 30L发酵罐发酵试验表明 ,利用高产突变株发酵 ,A 相似文献
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新型抗生素AGPM产生菌藤黄灰链霉菌的诱变育种 总被引:4,自引:1,他引:3
从土壤中分离得到一株藤黄灰链霉菌的新菌株099,该菌株能产生一种具有显抗肿瘤活性的新型抗生素AGPM。产生菌经紫外线单因子诱变、紫外线加氯化锂(LiCl)复合诱变等两种诱变方式诱变处理后,其AGPM产量达到了18.7μg/mL,较出发菌株提高了1.2倍。研究发现最忧的紫外辐射时间和氯化锂浓度分别是30-60s和0.05-0.09mol/L,并且由于氯化锂的协同效应,菌株在经氯化锂处理后,对紫外线的敏感性明显增强了。30L发酵罐发酵试验表明,利用高产突变株发酵,AGPM产量能达到18.5μg/mL;而利用出发菌株发酵,AGM产量仅为8.5μg/mL。 相似文献
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高产紫杉醇菌株的诱变选育及其差异表达基因消减cDNA文库的构建 总被引:1,自引:0,他引:1
[目的]选育高产紫杉醇菌株,并构建选育到的高产紫杉醇菌株与出发菌株HD1-3差异表达的cDNA消减文库.[方法]分别采用硫酸二乙酯和紫外线与硫酸二乙酯复合诱变处理菌株HD1-3孢子;以选育到的高产紫杉醇菌株为tester,菌株HD1-3为driver,应用抑制性消减杂交技术构建选育到的高产紫杉醇菌株与菌株HD1-3差异表达的cDNA消减文库.[结果]试验确定的Nodulisporium sylviforme紫杉醇产生菌HD1-3孢子复合诱变的适宜条件为:将106cfu/mL孢子悬液经过8%硫酸二乙酯处理15 min后,在电磁搅拌下,用紫外灯(30 w,距离30 cm)照射处理45 s,获得了1株遗传性状稳定、高产紫杉醇的突变株--UD14-11,其紫杉醇产量从出发菌株HD1-3的232.73±4.61μg/L提高至312.81±7.51μg/L;构建的文库滴度为1.2×107cfu/mL,阳性克隆率75.3%,片段大小主要集中在300 bp-1.0kb.[结论]选育到了1株遗传性状稳定、高产紫杉醇突变株;成功地构建了高产紫杉醇菌株UD14-11与菌株HD1-3差异表达的cDNA消减文库,为寻找、分离微生物生物合成紫杉醇相关基因和利用基因工程或代谢工程手段定向设计改造菌株奠定基础. 相似文献
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紫杉醇产生菌Nodulisporium sylviforme原生质体诱变研究 总被引:5,自引:0,他引:5
对酶系组成、pH、酶解温度和酶解时间等影响树状多节孢原生质体制备和再生的因素和原生质体诱变进行了研究。结果表明 ,原生质体制备和再生的最佳条件为 :用pH5.5~ 6.0的0.7mol/LNaCl配制由 3%溶壁酶 + 3%蜗牛酶 + 1 %的溶菌酶 + 3%纤维素酶组成的复合酶系 ( 1ml酶液/2 5 0mg湿菌体 ) ,在 30℃恒温水浴条件下酶解 6h ;然后 ,将获得的原生质体过滤洗涤后 ,在含0.7mol/ LNaCl的PDA再生培养基上 ,采用双层平板培养法再生制备到的原生质体。树状多节孢紫杉醇产生菌原生质体诱变的最佳条件为 :30w紫外灯、距离 30cm、照射 5 0s;UV + 0.6%LiCl复合诱变、照射时间 40s,诱变菌株经初筛和复筛 ,选出了两株高产紫杉醇的原生质体诱变菌株———UV40-19和UL50-6,其产量从出发菌株紫杉醇的产量 ( 314.07μg /L)分别提高至 376.38μg/L和392.63μg/L。 相似文献
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高产虾青素红法夫酵母的紫外线诱变 总被引:1,自引:0,他引:1
虾青素(3,3'-二羟基-β,β'-胡萝卜素-4,4'-二酮)是一种类胡萝卜、素类物质,具有巨大的开发价值。本文通过单一紫外线、紫外线-氯化锂复合处理,结合选择性平板的筛选作用,对菌株G26进行诱变育种。实验结果表明:紫外线照射3~9min,法夫酵母的死亡率在70%~95%之间;当死亡率为78.57%时,正变率达到最大值71.43%。经多次单独紫外线处理,以及紫外线-氯化锂复合诱变,获得稳定高产突变株G49,虾青素产量达到10 321μg/L,含量为713.8μg/g DCW,较出发菌株G26分别提高31.48%和20.47%。 相似文献
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为进一步筛选高产灰黄霉素的工业生产菌株,分别对前期采用紫外线-氯化锂(UV-LiCl)、半导体激光(LD laser)及CO2激光(CO2laser)对展青霉FS80-1复合诱变获得三株高产菌株进行液体发酵和固体培养比较。结果表明,通过UV-LiCl复合诱变获得突变菌株GM120-43的液体发酵产灰黄霉素效价11 982μg/mL,比出发菌株提高37.52%,固体培养效价为89 496μg/g(干重),比出发菌株提高80.04%。;半导体激光诱变获得突变株LD100-1的液体发酵效价9 440μg/mL,固体培养效价119 766μg/g干重,比出发菌株FS80-1提高了140%;两个突变株的生物学特性均发生不同程度的变化,突菌株GM120-43适合于液体发酵生产,突变株LD100-1适合于固体发酵培养。 相似文献
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保加利亚乳杆菌H+-ATPase缺陷型菌株的筛选 总被引:3,自引:0,他引:3
【目的】从传统乳制品中筛选具有新霉素抗性的H+-ATPase缺陷的德氏乳杆菌保加利亚亚种自发突变株,为最终开发弱后酸化的酸奶发酵剂奠定基础。【方法】利用API 50 CH细菌鉴定系统和16s rRNA基因序列分析对菌株进行鉴定。新霉素作为筛选压力,筛选具有新霉素抗性自发突变菌株,比较亲本和突变菌株的H+-ATPase活力及其代谢情况。【结果】从内蒙古地区的传统发酵酸奶中分离鉴定出一株德氏乳杆菌保加利亚亚种(Lactobacillus delbrueckii subsp. bulgaricus),并命名为KLDS 1.9201。以此为出发菌株,筛选出两株H+-ATPase缺陷的自发突变株,分别命名为KLDS 1.9201-1、KLDS 1.9201-4,它们的H+-ATPase活力分别比亲本KLDS 1.9201降低了46%和60%。在MRS培养基中生长24 h后,KLDS 1.9201、KLDS 1.9201-1和KLDS 1.9201-4对初始葡萄糖的代谢率分别为65%、41%和31%,终产物中乳酸的浓度分别为26g/L、18g/L和15g/L,突变菌株的生物量均低于亲本。【结论】H+-ATPase活力降低的德氏乳杆菌保加利亚亚种的自发突变株具有较低的生长速率和弱产酸能力,它们可被用于制作弱后酸化的酸奶发酵剂。 相似文献
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[背景]洛蒙德链霉菌S015能生物合成具有广谱抗菌活性的吩嗪类化合物洛蒙真菌素。[目的]因S015菌株的洛蒙真菌素产量较低,将S015菌株经复合诱变育种和基因工程改造,提高洛蒙真菌素产量。[方法]建立洛蒙真菌素产生菌的高通量筛选方法,对出发菌株S0 15进行常压室温等离子体(atmospheric and room temperature plasma,ARTP)技术和紫外复合诱变,筛选得到高产菌株;并在高产菌株上敲除洛蒙真菌素的前体分支酸竟争途径中的关键基因trpE1、trpE2,再过表达全局调控基因afsR。[结果]利用洛蒙真菌素在紫外波长375 nm处的特征吸收峰,以及洛蒙真菌素浓度和375 nm处吸光度值的正相关关系,建立了基于24孔深孔板发酵和酶标仪快速检测的高通量筛选方法。经过6轮ARTP和紫外复合诱变及高通量筛选,从4 320株突变株中筛选得到遗传稳定的高产菌株M6,其洛蒙真菌素的产量为61.33 mg/L,是S015菌株的7.35倍;M6菌株的分支途径基因trpE1、trpE2双敲株的洛蒙真菌素产量为81.89 mg/L,是S015菌株的9.82倍;在该基因工程菌株中过表达全局调控基因afsR,产量为109.53 mg/L,是S015菌株的13.13倍。[结论]建立的高通量筛选方法可以有效筛选高产洛蒙真菌素的突变株,并且操作简单快速。通过ARTP和紫外复合诱变,结合高产株M6的基因工程改造,能进一步提升洛蒙真菌素的产量。 相似文献
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Aspergillus niger ORS-4.410, a mutant of Aspergillus niger ORS-4 was produced by repeated irradiation with UV rays. Treatments with chemical mutagnes also resulted into mutant strains. The mutants differed from the parent strain morphologically and in gluconic acid production. The relationship between UV treatment dosage, conidial survival and frequency of mutation showed the maximum frequency of positive mutants (25%) was obtained along with a conidial survival of 59% after second stage of UV irradiation. Comparison of gluconic acid production of the parent and mutant ORS-4.410 strain showed a significant increase in gluconic acid production that was 87% higher than the wild type strain. ORS-4.410 strain when transferred every 15 days and monitored for gluconic acid levels for a total period of ten months appeared stable. Mutant ORS-4.410 at 12% substrate concentration resulted into significantly higher i.e. 85-87 and 94-97% yields of gluconic acid under submerged and solid state surface conditions respectively. Further increase in substrate concentration appeared inhibitory. Maximum yield of gluconic acid was obtained after 6 days under submerged condition and decreased on further cultivation. Solid state surface culture condition on the other hand resulted into higher yield after 12 days of cultivation and similar levels of yields continued thereafter. 相似文献
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S P Bocking M G Wiebe G D Robson K Hansen L H Christiansen A P Trinci 《Biotechnology and bioengineering》1999,65(6):638-648
Highly branched mutants of two strains of Aspergillus oryzae (IFO4177, which produces alpha-amylase, and a transformant of IFO4177 [AMG#13], which produces heterologous glucoamylase in addition to alpha-amylase) were generated by UV or nitrous acid mutagenesis. Four mutants of the parental strain (IFO4177), which were 10 to 50% more branched than the parental strain, were studied in stirred batch culture and no differences were observed in either the amount or the rate of enzyme production. Five mutants of the transformed parental strain (AMG#13), which were 20 to 58% more branched than the parental strain, were studied in either batch, fed-batch or continuous culture. In batch culture, three of the mutants produced more glucoamylase than the transformed parental strain, although only two mutants produced more glucoamylase and alpha-amylase combined. No increase in enzyme production was observed in either chemostat or fed-batch culture. Cultures of highly branched mutants were less viscous than those of the parental and transformed parental strains. A linear relationship was found between the degree of branching (measured as hyphal growth unit length) and culture viscosity (measured as the torque exerted on the rheometer impeller) for these strains. DOT-controlled fed-batch cultures (in which the medium feed rate was determined by the DOT) were thus inoculated with either the transformed parent or highly branched mutants of the transformed parent to determine whether the reduced viscosity would improve aeration and give higher enzyme yields. The average rate of medium addition was higher for the two highly branched mutants (ca. 8.3 g medium h(-1)) than for the parental strain (5.7 g medium h(-1)). Specific enzyme production in the DOT controlled fed-batch cultures was similar for all three strains (approx. 0.24 g alpha-amylase and glucoamylase [g of biomass](-1)), but one of the highly branched mutants made more total enzyme (24.3 +/- 0.2 g alpha-amylase and glucoamylase) than the parental strain (21.7 +/- 0.4 g alpha-amylase and glucoamylase). 相似文献
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【目的】通过诱变筛选技术选育阿维菌素高产突变株,对其发酵培养基进行响应面优化,提高阿维菌素产量。【方法】采用常压室温等离子体(ARTP)诱变技术,结合链霉抗性和卡那霉素抗性筛选法及96深孔板高通量筛选法,筛选阿维菌素高产株。在单因素实验的基础上,应用响应面分析法对其发酵培养基进行优化,最后确定最佳培养基配方。【结果】获得一株遗传性状稳定的阿维菌素高产株K-1A6,其阿维菌素产量达到4.22 g/L,比出发菌株9-39提高了23.4%,在最佳培养基中阿维菌素产量达到5.36 g/L,较优化前提高了27.01%。【结论】通过对阿维链霉菌9-39菌株进行ARTP诱变筛选及发酵培养基优化研究能显著提高阿维菌素的产量。 相似文献