共查询到16条相似文献,搜索用时 78 毫秒
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曲酸生产菌的诱变选育 总被引:5,自引:0,他引:5
Aspergillus oryzae 2336两次紫外诱变后筛选出突变苗株UV21012-1。该菌株曲酸产量比出发菌提高了1.68倍;遗传性状稳定,传代5次曲酸产量基本不下降,而且发酵周期也比出发菌株明显缩短。 相似文献
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复合诱变对米曲霉产曲酸的影响 总被引:4,自引:0,他引:4
发酵法生产曲酸还未实现大规模工业化生产的原因之一是曲酸菌种产酸率较低,本文以平展米曲霉(Aspergillus oryzae effusus)AS32为出现菌株,经UV和^60Co诱变处理,筛选获得一株高产曲酸变异株AUR163,以葡萄糖为碳源,酵母膏为氮源,32℃摇瓶和30L罐发酵培养4天,产酸达6.8g/100mL。平均生产效率为17.0g/L.d最高可达30.5g/L.d比出发菌AS32提高190%以上,这表明UV和^60Co作诱剂,可以大幅度提高米曲霉的曲酸生产效率。 相似文献
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曲酸菌选育及发酵工艺研究 总被引:8,自引:0,他引:8
筛选获得产曲酸菌株米曲霉(Aspergillusoryzae)MSA进行60Co诱变,并进行了发酵工艺条件研究,以葡萄糖为碳源、豆饼粉为氮源,在pH3.0、33℃摇瓶培养,可达到5d产酸5%以上水平。发酵液采用直接浓缩结晶工艺,脱色与重结晶后获得无色针状晶体,红外图谱检测确证为曲酸。 相似文献
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曲酸产生菌激光诱变效应的研究 总被引:3,自引:0,他引:3
采用经紫外线(UV)、^60Co、亚硝基胍(NTG)复合诱变得到的黄曲霉曲酸产生菌(UCN7—12),进行激光诱变处理。研究证实在经过UV、^60Co、NTG诱变处理后,黄曲霉突变株用He—Ne激光与YAG激光进行诱变处理仍能提高产酸率,其中He—Ne激光辐照处理20min,正变率为12.1%,产量提高约13%。YAG激光辐照处理300sec,正变率16.7%,产量提高18.3%。说明上述两种激光对黄曲霉曲酸产生菌有一定的诱变效应。 相似文献
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紫外诱变选育米曲霉高产蛋白酶菌株 总被引:16,自引:0,他引:16
以从自然发酵黄豆酱中筛选的5株野生米曲霉为供试菌株,以这些菌株产蛋白酶(酸、中、碱)、淀粉酶(α-淀粉酶、糖化酶)活力大小为评价标准,筛选出米曲霉K61作为诱变出发菌株。采用紫外诱变对米曲霉K61菌株进行改造,最终筛选出一株蛋白酶活力高且遗传性能稳定的突变株Y29。将米曲霉Y29菌株应用于黄豆酱的生产中,并与目前工业生产中广泛应用的米曲霉沪酿3.042菌株进行比较。性能实验结果表明米曲霉Y29菌株的蛋白酶(酸、中、碱)活力明显高于米曲霉沪酿3.042菌株,但α-淀粉酶、糖化酶、生长速度和孢子数这4个指标两者的差异并不显著;制酱品质试验结果表明,米曲霉Y29菌株的酱香更浓郁一些,氨基酸态氮含量达到0.77g/100mL,高于米曲霉沪酿3.042菌株,其它指标均符合国家标准GB2718-1996。 相似文献
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分离到Aspergilusoryzae13个菌株,其曲酸产量变化幅度166—486mg/ml,从中选出4个高产菌株。在1%酵母提取物和15%蔗糖培养液中30℃发酵培养,8—10天菌体生长量和曲酸产量达到最大值,随后曲酸产量迅速下降。蔗糖浓度对菌体生长和曲酸产量影响甚大,最适蔗糖浓度为15%。天冬氨酸、甘氨酸、赖氨酸、谷氨酸、吡哆醇、叶酸和抗坏血酸有利于菌体生长并显著提高曲酸产量。将在YES培养液中培养10天的菌体重新悬浮于含15%蔗糖的YES培养液或02M磷酸缓冲液(pH65)中8—10天曲酸产量仍可达到45mg/ml以上。低温条件下制备的培养8—10天的Aoryzae菌体匀浆反应系统仅有痕量曲酸形成。 相似文献
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分离到Aspergillus oryzae13个菌株,其曲酸产量变化幅度16.6-48.6mg/ml,从中选出4个高产菌株。在1%酵母提取物和15%蔗糖培养液中30℃发酵培养,8 ̄10天菌体生长量和曲酸产量达到最大值,随后曲酸产量迅速下降。蔗糖浓度对菌体生长和曲酸产量影响甚大,最适蔗糖浓度为15%。天冬氨酸、甘氨酸、赖氨酸、谷氨酸、吡哆醇、叶酸和抗坏血酸有利于菌体生长并显著提高曲酸产量。将在YES 相似文献
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曲酸的发酵生成与检测 总被引:4,自引:0,他引:4
本文概述曲霉发酵合成曲酸所需的各种营养因素及其对产酸力的影响,发酵工艺与菌种诱变,合成机理,曲酸的鉴定和检测方法,并对发酵工艺的发展趋势提出一些看法。 相似文献
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《Bioscience, biotechnology, and biochemistry》2013,77(9):1832-1834
Kojic acid synthesis genes regulation was investigated in Aspergillus oryzae. Our results indicate that kojic acid production was lost in the laeA disruption strain, but was recovered in the LaeA complement strain. Real-time PCR also confirmed that expression of kojic acid biosynthesis genes decreased in the laeA disruption strain, indicating that these genes are under the control of LaeA. 相似文献
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Effect of Kojic Acid on the Oxidation of DL-DOPA,Norepinephrine, and Dopamine by Mushroom Tyrosinase
VARDA KAHN 《Pigment cell & melanoma research》1995,8(5):234-240
Kojic acid inhibits effectively the rate of formation of pigmented product(s) and of oxygen uptake when DL-DOPA, norepinephrine and dopamine are oxidized by mushroom tyrosinase. In addition to the direct effect of kojic acid on the enzyme, kojic acid also affects the UV-VIS spectrum of the final product(s) formed, this being due to the ability of the o-quinones of these substrates to oxidize kojic acid to a yellow product(s). Kojic acid can thus prevent the conversion of the o-quinones of DL-DOPA, norepinephrine and dopamine to their corresponding melanin. 相似文献
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Aryl pyrazoles are well recognized class of heterocyclic compounds found in several commercially available drugs. Owing to their significance in medicinal chemistry, in this current account we have synthesized a series of suitably substituted aryl pyrazole by employing Suzuki cross-coupling reaction. All compounds were evaluated for inhibition of mushroom tyrosinase enzyme both in vitro and in silico. Compound 3f (IC50 = 1.568 ± 0.01 µM) showed relatively better potential compared to reference kojic acid (IC50 = 16.051 ± 1.27 µM). A comparative docking studies showed that compound 3f have maximum binding affinity against mushroom tyrosinase (PDBID: 2Y9X) with binding energy value (−6.90 kcal/mol) as compared to Kojic acid. The 4-methoxy group in compound 3f shows 100% interaction with Cu. Compound 3f displayed hydrogen binding interaction with His61 and His94 at distance of 1.71 and 1.74 Å which might be responsible for higher activity compared to Kojic acid. 相似文献