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以经紫外线诱变后获得的氢化可的松转化菌株新月弯孢霉 2 1 50 # 为出发菌株 ,经纤维素酶及溶菌酶作用形成原生质体 ,并对原生质体进行硫酸二乙酯 (DES)诱变 ,然后对大量的再生突变株进行筛选 ,获得高氢化可的松转化率菌株 8 68# ,其氢化可的松转化率较出发菌株提高了 56.8%。 相似文献
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利用紫外线、利福平、氯化锂诱变原生质体筛选L—亮氨酸高产菌株的研究 总被引:5,自引:0,他引:5
本实验是以黄色短杆菌T_(6—13)的诱变株L—亮氨酸产生菌D—R—4为出发菌株,经青霉素、甘氨酸、溶菌酶作用制备原生质体,形成率达91.30%,再生率达53.68%;然后对原生质体进行紫外线、利福平、氯化锂复合诱变处理;在再生培养基平皿上培养,获得再生突变株,从中挑取单独菌落,进行摇瓶发酵筛选,已选育出一株57—4S号高产稳定菌株;经氨基酸分析仪测定其发酵液L—亮氨酸产量由出发菌株的17.35mg/ml提高到23.45mg/ml提高了35%。发酵液中主要副酸——异亮氨酸含量很少。 相似文献
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紫外诱变原生质体选育赖氨酸高产菌株 总被引:16,自引:0,他引:16
以钝齿棒杆菌102S2-58为出发菌株,在原生质体形成及再生的最佳条件下制备原生质体,并对原生质体进行紫外诱变处理,对大量的再生突变株进行发酵筛选.获得了高产稳定株102-100号,其发酵液经氨基酸自动分析仪测定L-赖氨酸积累量由出发菌株的5O.Omg/ml提高到80.8mg/ml,糖转化率达到63.88%.发酵液中主要副产酸——纈氨酸和蛋氨酸的量明显降低。 相似文献
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以灰黄青霉菌(Penicillium griseofulvum HL)为出发菌株,试验得到灰黄青霉原生质体制备的优化条件为:菌体培养48h,用0.7mol/L的NaC1溶液作为渗透压稳定剂,用0.5%的蜗牛酶+0.5%的纤维素酶,在pH为6,30℃条件下酶解3h,所得原生质体数最多,达到3.14×107/ml.原生质体再生的最佳条件为采用双层平板培养法,在用0.7mol/L的蔗糖溶液配制的改进察氏培养基上其再生率最高,达到24.93%.灰黄青霉原生质体经过紫外线诱变,DES诱变,紫外线-DES诱变复合诱变,紫外线-氯化锂复合诱变选育异抗坏血酸高产菌株,通过对再生平板上长出的诱变菌株进行初筛和摇瓶复筛,最终获得一株异抗坏血酸产量较高的菌株ZD4,其产量为5.28mg/ml,提高到出发菌株产量(1.08 mg/ml)的488.9%,且连续传代6代遗传稳定. 相似文献
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本文通过研究酶组合、酶浓度、酶作用时间和菌龄等因素对天麻素产生菌华根霉(Rhizopus chinensis) LN-A原生质体制备和再生的影响, 总结出了原生质体制备和再生的最佳条件: 选用对数生长期的菌株, 以蜗牛酶5 mg/mL + 纤维素酶5 mg/mL + 溶菌酶2 mg/mL 30°C保温处理2 h, 原生质体形成率达5.8×107, 原生质体再生率为5.7%。在此基础上首次利用He-Ne激光、紫外线复合诱变天麻素合成菌的原生质体, 当选用15 mW的He-Ne激光辐射原生质体20 min, 再用紫外辐照150 s时获得了转化率及天麻素得率都明显提高的突变株, 其天麻素得率比出发菌株提高20%以上。 相似文献
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D. G. Lyutskanova M. M. Stoilova-Disheva V. T. Peltekova 《Applied Biochemistry and Microbiology》2005,41(2):165-168
Conventional mutagenesis (UV irradiation and exposure to nitrosoguanidine) as well as protoplast formation and regeneration were used to improve the antibiotic activity of a Streptomyces fradiae strain producing tylosin. Variants exceeding the activity of the initial producer strain by 0.5–28.3% were obtained. The most active variants were produced by a combined exposure to UV and nitrosoguanidine, as well as upon regeneration of protoplasts formed from the cells of clones produced by UV irradiation. Unstable inheritance of the trait of increased tylosin production was demonstrated.Translated from Prikladnaya Biokhimiya i Mikrobiologiya, Vol. 41, No. 2, 2005, pp. 189–193.Original Russian Text Copyright © 2005 by Lyutskanova, Stoilova-Disheva, Peltekova. 相似文献
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以肺炎克雷伯氏杆菌(Klebsiella pneumoniae)为研究对象,应用原生质体紫外诱变技术提高其对甘油及1,3-丙二醇的耐受性,获得1,3-丙二醇高产菌.在原生质体制备过程中,运用滤膜去除酶解后细胞悬液中的正常菌体,简化菌体酶解过程,提高再生率及形成率.经过原生质体诱变后,以耐受高浓度甘油和1,3-丙二醇及高产酸能力为筛选方向,最终筛选到了3株高产菌株(Kp-1、Kp-4和Kp-5).在补料发酵实验中,上述诱变菌产1,3-丙二醇能力分别为70.24 、65.21和75.51 g/L,比野生菌株WT(55.78 g/L)分别提高了25.92%、16.91%和35.37%. 相似文献
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The production of a low-temperature alkalophilic lipase from Acinetobacter johnsonii was improved using genome shuffling. The starting populations, obtained by UV irradiation and diethyl sulfate mutagenesis,
were subjected to recursive protoplast fusion. The optimal conditions for protoplast formation and regeneration were 0.15 mg
lysozyme/ml for 45 min at 37°C. The protoplasts were inactivated under UV for 20 min or heated at 60°C for 60 min and a fusant
probability of ~98% was observed. The positive colonies were created by fusing the inactivated protoplasts. After two rounds
of genome shuffling, one strain, F22, with a lipase activity of 7 U/ml was obtained. 相似文献
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Mamta Singhvi Dipti Joshi Shalaka Gaikaiwari Digambar V. Gokhale 《Indian journal of microbiology》2010,50(1):97-100
Method for production and regeneration of Lactobacillus delbrueckii protoplasts are described. The protoplasts were obtained by treatment with a mixture of lysozyme and mutanolysin in protoplast
buffer at pH 6.5 with different osmotic stabilizers. The protoplasts were regenerated on deMan, Rogosa and Sharpe (MRS) with
various osmotic stabilizers. Maximum protoplast formation was obtained in protoplast buffer with sucrose as an osmotic stabilizer
using a combination of lysozyme (1 mg/ml) and mutanolysin (10 μg/ml). Maximum protoplast regeneration was obtained on MRS
medium with sucrose (0.5 M) as an osmotic stabilizer. The regeneration medium was also applicable to other species of lactobacilli
as well. This is, to our knowledge, the first report on protoplast formation and efficient regeneration in case of L. delbrueckii. 相似文献
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Induction and Characterization of Artificial Diploids from the Haploid Yeast Torulaspora delbrueckii 总被引:2,自引:2,他引:0 下载免费PDF全文
The yeast Torulaspora delbrueckii, which propagates as a haploid, was made into a diploid by treatment with dimethyl sulfoxide (DMSO) on the regeneration of protoplasts. The diploid state was stably inherited; the cell volume was three times that of the parent strain and the cellular DNA content was two times that of the parental strain. No essential difference was found between diploids induced by DMSO and those formed through intraspecific protoplast fusion. The diploid strains sporulated fairly well, with their cells converting directly into asci. Random spore analysis revealed that diploids induced through protoplast fusion gave rise to auxotrophic segregants (haploids) with the parental genetic marker or to segregants formed by recombination, while diploids induced by DMSO from a doubly auxotrophic parent gave rise to no recombinant, indicating that it was chromosomally homoallelic in nature. The magnesium level in the protoplast regeneration medium was found to be an important factor for inducing diploid formation. At 0.2 mM magnesium diploids appeared even in the absence of DMSO, while at 2 mM magnesium diploids never appeared unless DMSO was added to the regeneration medium. Evidence is provided that the diploids induced by DMSO or a low magnesium level are due to direct diploidization but not protoplast fusion. UV light irradiation of intact cells (without protoplasts), 10% of which survived, also produced diploids among this surviving population. From these results we conclude that the perturbation of protoplast regeneration or of cell division by the treatments mentioned above somehow induced direct diploidization of T. delbrueckii. 相似文献
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O L Krasil'nikova L N Anisova N B Romanova Iu E Bartoshevich 《Antibiotiki i khimioterapii͡a》1988,33(7):483-486
Conditions for efficient regeneration in mutant strains of the doxorubicin-producing organism Str. peucetius var. caesius were developed. The effect of the protoplast regeneration on changes in the proportion of the components of the anthracycline complex produced by these strains was shown. Variants with doxorubicin productivity 2 times higher than that of the parent strain were isolated. 相似文献
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本研究以实验室自主分离的枯草芽孢杆菌mutHS-301为出发菌株,通过原生质体紫外诱变选育出高产抗菌脂肽突变菌株,并对其产生的抗菌脂肽提取物进行单组分分离纯化及对黄曲霉抑制作用进行初步研究。结果表明,在溶菌酶浓度为0.5 mg/mL,酶解时间为15 min,酶解温度为37℃条件下,获得原生质体的形成率和再生率效果最佳。采用紫外照射时间60 s进行该原生质体诱变,经筛选获得一株遗传性状稳定的高产抗菌脂肽菌株,命名为mutHS-539。研究表明,该突变株mutHS-539发酵上清液对副溶血性弧菌和金黄色葡萄球菌抑菌直径较原始菌mutHS-301分别提高了21.49%和21.05%,提取得到的抗菌脂肽产量较原始菌提高了40%。利用制备型硅胶板对发酵提取物进行分离纯化得到四种组分,分别为a、b、c和d;进一步检测对黄曲霉的抑菌活性,结果发现只有组分d对黄曲霉具有显著的抑制作用。经RP-HPLC分析及液质联用数据比对,该组分d的主要成分为杆菌霉素D。该抗菌脂肽提取物对黄曲霉抑制作用的研究显示,当抗菌脂肽浓度为0.2 mg/mL时能有效抑制黄曲霉菌丝的生长,抑制率达到了74.22%,且对黄曲霉孢子的致死浓度为0.8 mg/mL。 相似文献