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为获得产纳豆激酶(nattokinase,NK)活力增强的菌株,以纤维蛋白平板法测得酶活力值为判定指标,采用常压室温等离子体诱变系统(ARTP)对枯草芽孢杆菌XZI125进行诱变,通过酪蛋白平板法和利福平、卡那霉素、链霉素、氯霉素四种抗生素抗性筛选法获得高产NK突变菌株。结果表明,经6轮摇瓶发酵验证,获得了3株遗传稳定的高产突变菌株A27,Ar41和Ac35,摇瓶发酵5 d的产酶活力分别比原始菌株(2490 IU/mL)提高了23.0%、25.1%、26.5%。比较酪蛋白平板筛选方法和0.7 μg/mL利福平、50 μg/mL卡那霉素、60 μg/mL链霉素、300 μg/mL氯霉素四种抗性筛选方法,抗生素抗性筛选方法更有利于NK高产菌株的筛选。 相似文献
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该研究将室温等离子(ARTP)诱变与微生物微滴培养(MMC)技术应用于几丁质脱乙酰基酶(CDA)高产菌株的诱变选育,构建高产CDA菌株的诱变及高通量筛选方法。结果表明,经过4轮的ARTP诱变及MMC筛选,从200个不同的液滴中共筛选出5个发酵产酶明显提升的液滴,并通过进一步的平板筛选、24-深孔板复筛,获得了17株产酶提高300%以上的诱变菌株。通过对比分析17株高产菌株产CDA的能力,确定了1株最佳CDA高产菌株B4,其CDA最大产量比出发菌株提高了3.15倍,发酵产酶总量达到419.11 U/mL,为原始菌种的3.90倍。该研究为CDA高产菌株的诱变选育及高通量筛选提供了借鉴。 相似文献
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利用紫外线诱变育种方法分离对前期分离到一株葡聚糖酶野生菌株P5进行诱变。通过平板初筛、摇瓶复筛,从诱变菌株中筛选出一株高产菌株,其发酵酶活力可以达到5.85U/mL;在此基础上,对诱变菌株的发酵产酶工艺进行了初步的优化,其最适碳源为淀粉,最适氮源为花生饼粉,正交试验结果表明,淀粉含量为5%、花生饼粉含量为4%、NaH2PO4含量为0.2%时,该菌株的产酶量最高,酶活力达到21.23U/mL。 相似文献
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该研究采用平板酶解圈法从南海海域海藻、动物及沉积物样品中筛选产褐藻胶裂解酶细菌,对筛选菌株进行分子生物学鉴定,并利用常压室温等离子体(ARTP)诱变技术选育高产褐藻胶裂解酶菌株。结果表明,共分离筛选得到酶活较高的细菌14株,16S rDNA比对分析结果表明,它们隶属于3个门、5个纲、7个目、8个科、9个属,其中有5株菌(占35.7%)可能代表着新的分类单元。以高产褐藻胶裂解酶海藻类芽孢杆菌(Paenibacillus algicola)HB172198T作为原始菌株,利用ARTP诱变技术选育获得2株褐藻胶裂解酶活力明显提高的突变株(编号分别为30-19、80-6),其酶活力分别比原始菌株提高了32.6%和21.6%,且连续6次传代培养诱变菌株的产酶遗传性状稳定。 相似文献
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以枯草芽孢杆菌 YL-P2、YL-F2作为出发菌株,分别采用紫外线诱变、硫酸二乙酯诱变以及紫外线和硫酸二乙酯复合诱变,以脱脂牛奶平板法为初筛方法结合纤维蛋白平板复筛的方法选育出溶纤酶活力高的菌株, 获得了高产溶纤酶菌株 UV-8。UV-8溶纤酶活力达到2 314 IU/mL,与出发菌株相比,酶活力提高了2倍。结果表明,经多次传代后菌株 UV-8的溶纤酶酶活达到稳定,具有很好的潜在开发前景。 相似文献
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目的:从豆豉中分离出高产蛋白酶的菌株并进行紫外诱变,以提高菌株的产蛋白酶能力.方法:采用酪蛋白平板法,初步筛选出一些产蛋白酶菌株,通过比较发酵后蛋白酶活力,筛选出一株产蛋白酶活力最高的菌株,鉴定其菌种,对该菌株进行紫外诱变,并对诱变后的菌株进行筛选,最后得到一株产蛋白酶活力最高的菌株.结果:分离鉴定后得知菌株B为地衣芽孢杆菌,产蛋白酶活力为2360.80U/mL.最佳诱变时间为120s,菌落致死率为66.68%,得到的高产蛋白酶菌株为B-14,其蛋白酶活力为2922.90U/mL,诱变后菌株产蛋白酶活力提高了23.81%.结论:通过筛选、诱变成功选育出高产蛋白酶的菌株B-14. 相似文献
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以自主分离的植物乳杆菌LY-78为出发菌株,通过亚硝基胍法诱变,以抑菌效价为检测指标,采用双层平板拮抗法和牛津杯琼脂扩散法筛选突变菌株。对筛选的突变菌株进行发酵试验,采用反相高效液相色谱法定量检测苯乳酸含量,然后根据产苯乳酸含量的多少,确定最佳菌株。试验结果表明,亚硝基胍诱变质量浓度为1.0 mg/mL、诱变时间为40 min时所获得的突变菌株NY-34具有较高的苯乳酸产量,即648 mg/L,比诱变前(246 mg/L)提高2.63倍。 相似文献
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该研究采用常压室温等离子体(ARTP)诱变技术对黑曲霉(Aspergillus niger)xj进行诱变,通过考察致死率与正突变率确定最佳诱变时间,通过发酵培养选育高产微生物絮凝剂菌株。结果表明,黑曲霉xj的最佳诱变照射时间为90 s;经初筛共得到416株诱变菌株;经复筛得到10株絮凝活性较高的诱变菌;再经同步发酵培养,比较突变菌的生长状态、絮凝活性及遗传稳定性,获得2株絮凝活性较高、稳定遗传的突变菌株A90-34与A90-37,其对高岭土悬液的絮凝率分别为94.12%和94.96%,与原始菌株相比,分别提高26.19%、27.03%,连续传代7次仍具有良好的遗传稳定性,絮凝率维持在92%~95%。 相似文献
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紫外诱变法选育酒酒球菌乙醇胁迫耐受菌株及其发酵性能研究 总被引:1,自引:0,他引:1
该研究以酒酒球菌(Oenococcus oeni)SD-2a为研究对象,采用紫外诱变法选育乙醇胁迫耐受突变菌株,评价其在乙醇胁迫条件下的生长能力,并测定其产β-葡萄糖苷酶活性及其在模拟酒中苹果酸、乳酸含量及活菌数的变化。结果表明,分离筛选到3株乙醇胁迫耐受性好的突变菌株,分别编号为UVe1、UVe2、UVe3,在高体积分数乙醇(12%和14%)胁迫环境下,3株突变菌株的生长速度均显著高于出发菌株SD-2a(P<0.05);突变菌株UVe2的β-葡萄糖苷酶活性显著高于出发菌株SD-2a和对照菌株L-450(P<0.05);在模拟酒中,3株突变菌株的苹果酸降解与乳酸生成速度均显著高于出发菌株SD-2a(P<0.05),且突变菌株UVe1和UVe2的存活率显著高于出发菌株SD-2a(P<0.05);综上,突变菌株UVe2具有优良商业酒酒球菌的潜力。 相似文献
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为得到酱油酿造优良性状的微生物,对酱油酿造用T酵母进行研究。首先利用易错聚合酶链式反应(polymerase chain reaction,PCR)技术构建spt15(可编码TATA结合蛋白)的突变基因库,然后重组于表达载体YEplac195中,并导入尿嘧啶营养缺陷型菌株W303和WM2中筛选。结果表明:在不同盐质量分数的固体培养基中经筛选获得4?个最佳突变菌株,其具有耐盐优势,在酱油发酵中可产生较高的氨基酸态氮。经PCR产物测序可知,重组质粒中目的基因的序列有碱基的增添、缺失和替换。 相似文献
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Mutants of Aspergillus parasiticus highly resistant to phenylpyrroles were isolated at a high mutation frequency, after UV-mutagenesis and selection on media containing fludioxonil. Studies on the effect of mutation(s) on the aflatoxin production resulted in the identification of two fludioxonil-resistant phenotypes: aflatoxigenic (FLD(afl)(+)) and non-aflatoxigenic (FLD(afl)(-)) mutant strains. Most of the FLD(afl)(+) mutant strains produced the aflatoxin B(1) at similar or even higher (up to 2.5-fold) concentrations than the wild-type parent strain on yeast extract sucrose medium. Interestingly, in most of these mutant strains the aflatoxigenic ability significantly increased (up to 4-fold) when the mutants were grown on fungicide-amended medium. However, a significant reduction in the aflatoxin production was observed in wheat grains by all FLD(afl)(+) mutant strains. Tests on the response of mutant strains to high osmotic pressure showed that most fludioxonil-resistant mutants were more sensitive to high osmolarity than the wild-type parent strain. Study of other fitness determining parameters showed that the mutation(s) for resistance to phenylpyrroles may or may not affect the mycelial growth rate, sporulation and conidial germination. However, in a number of aflatoxigenic-mutant strains these fitness parameters were unaffected or only slightly affected. Cross resistance studies with fungicides from different chemical groups showed that the mutation(s) for resistance to fludioxonil also highly reduced the sensitivity of mutant strains to the aromatic hydrocarbon and dicarboximide fungicides. No effect of phenylpyrroles resistance mutation(s) on fungitoxicity of triazoles, benzimidazoles, anilinopyrimidines, phenylpyridinamines, strobilurin-type fungicides and to the non site-specific inhibitors chlorothalonil and maneb was observed. The above mentioned data indicate, for the first time, the potential risk of increased aflatoxin contamination of agricultural products by the appearance and predominance of highly aflatoxigenic mutant strains of A. parasiticus resistant to aromatic hydrocarbon, dicarboximide and phenylpyrrole fungicides. 相似文献
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A Schizosaccharomyces pombe mutant deficient in Cu,Zn-superoxide dismutase (sod1 mutant) was hypersensitive to phloxine B, which is used as a food-colouring agent and also to distinguish diploid strains of Sz. pombe from haploid strains, under illumination with light. The pro-oxidant nature of phloxine B was confirmed biochemically. The carbonyl content of proteins (which represents protein oxidation) increased, and the reduced form of glutathione was transiently decreased by phloxine B treatment under illumination with light. When cells were treated with phloxine B under light, carbonyl content of proteins in the sod1 mutant was greater than that in the wild-type and amount of glutathione was much decreased in the sod1 mutant compared with the wild-type. Genes induced by oxidative stress were induced by phloxine B under illumination with light and some were induced by phloxine B without light. 相似文献