梧宁霉素产生菌诱变选育的研究

以不吸水链霉菌（Ｓｉｒｅｐｔｏｍｙｃｅｓａｈｙｇｒｏｓｅｌｃｎｓ）ＮＳ—２３为出发菌株。菌种斜面孢子萌动后采用紫外线（ＵＶ）、硫酸二乙酯（ＤＥＳ）、秋水仙素及加底物等物理化学因子进行诱变处理,经两代连续处理,从ＵＶ、ＤＥＳ的复合处理中选育出一株产素较高的突变株ＵＤＡ２５７－Ｃ－２４,产素效价比出发菌株提高了２９１．７２％     

黑曲霉单宁酶高活性菌株的诱变选育*

以黑曲霉（Ａｓｐｅｒｇｉｌｌｕｓ ｎｈｉｇｅｒ）Ｎｏ．１３为出发菌株,经紫外线诱变处理,获得一株制备原生质体的起始菌,该菌株单宁酶活性比Ｎｏ．１３提高５５％,并对其制备原生质体的条件进行了研究,在优化方案基础上,紫外诱变原生质体,诱变株经筛选,最后得到一株具有稳定遗传性的单宁酶高活性菌株,在摇瓶培养基中进行生物转化实验,连续传代１０次,结果显示发酵液中没食子酸浓度始 维持在２２．８－２３．９ｍｇ／     

几种诱变因子对龟裂链霉菌原生质体的影响

作者应用通电、ＵＶ、ＮＴＧ和亚硫酸氢钠等诱变因子对土霉素产生菌——龟裂链霉菌１３８—ｌ原生质体进行处理。结果表明,各种诱变因子在对原生质体致死率５０％左右时具有较好的诱变效应。经亚硫酸氢钠＋ＬｉＣｌ处理获得的Ｃｌ１８菌株通过１６５００１发酵罐试验,最高发酵水平达３３３３０ｕ／ｍｌ,平均发酵水平为３０５４２．５ｕ／ｍｌ,比出发菌株１３８—１提高２０．６％。     

从万古霉素抗性突变体中筛选碱性纤维素酶高产菌株

以芽胞杆菌 Ｘ—６ 为出发菌株,经甲基磺酸乙酯（ Ｅ Ｍ Ｓ） 和紫外线（ Ｕ Ｖ） 复合诱变,选育万古霉素抗性突变体。研究结果表明,抗药性突变株碱性羧甲基纤维素酶（ Ｃ Ｍ Ｃａｓｅ） 产量提高的正变率和正变幅度明显高于非抗药性菌株。从抗性突变株中获得 Ｅ Ｖ２３ 菌株,其产酶活力比出发株 Ｘ—６ 提高３２０ ％ ,酶活力达３５３ｕ／ ｍｌ。     

产谷氨酸棒杆菌B9和T6—13的原生质体融合

棒杆菌Ｂ９和Ｔ６—１３两菌株经ＵＶ变处理得到Ｂ９—２（ＳｍＲ）和Ｔ６—１３—３（ＲｉｆＲ）两菌株,以此两菌株做为出发菌株。将对数前期的培养细胞经青霉素予处理及酶解制备原生质体,用４０％ＰＥＧ６０００为助融剂,进行原生质体融合。用间接法检出具有Ｓｍ、Ｒｉｆ抗性的融合子。融合频率为６．５５×１０－６－１．６４×１０－５,融合子双抗性稳定,产谷氨酸,经摇瓶实验筛选出一株产谷氨酸明显高于亲本的融合子ｆｕ３６。     

羊肚菌原生质体诱变筛选高生物量高氨基酸含量菌株

研究影响尖顶羊肚菌ＣＧＡＣ－９５０６原生质体制备、再生因素基础上,首次诱变羊肚菌原生质体,进行高生物量高氨基酸含量菌株选育。原生质体诱变再生株Ｍ．ｃｏｎｉｃａ ＣＧＡＣ－９５０６３７生物量比出发株提高７．３％,总氨基酸比出发株提高３８％。     

灰黄霉素菌的诱变效应

以灰黄霉素产生菌D－756为出发菌株,经过三代紫外线＋氯化锂诱变处理,获得耐氯变株F－1012,该变株在形态特征及产量、耐氯性等方面均发生变化,当发酵培养基中的氯化物浓度由1.5%提高到2.0%,F－1012的大米孢子效价提高了34.5%;当固体平板培养基中氯化物浓度提高到11％时,F－1012的孢子存活率比出发菌株提高了25.5％。     

灵芝菌诱变育种与深层培养的研究

采用紫外线对灵芝菌进行了诱变处理,选育到一株高产菌株ＵＶ－６０Ｓ,其菌体干重达１３．１ｇ／Ｌ,粗多糖含量为６４０ｍｇ／Ｌ,分别比原菌株提高了２１．３％和３０．６％;并研究了培养基组成和培养条件对菌体生长的影响,优化了深层培养的工艺条件,使菌体产量与胞外多糖含量比优化前分别提高了１５．３％和１８．８％。     

香菇原生质体分离诱变育种研究

通过ＵＶ处理香菇原生质体后得到的１０５株再生菌株与它们亲本菌株的菌丝生长速度,产量和出菇期进行了比较。约有３０％的再生菌株获得了较高的产量和较早出菇期的优良特性、多次继代培养证明,这些再生菌株获得的优良特性稳定。研究结果表明,香菇原生质体分离诱变是一种很有应用价值的食用菌菌种选育方法。     

温度适应范围大的谷氨酸生产菌GMH—908选育,发酵及应用效果

以谷氨酸生产菌天津短杆菌（Ｂｒｅｖｉｂａｃｔｅｒｉｕｍｔｉｅｎｔｓｉｎｅｎｓ）Ｔ６－１３为出发菌株,经菌体或原生质体紫外线（ＵＶ）、氯化锂、香豆素等多因子诱变和高温驯化,选育出琥珀酸、生物素营养缺陷型,耐高糖、耐高谷氨酸又不利用谷氨酸,且温度适应范围大（既可在常温３２－３８℃发酵,又可在高温３６－４２℃发酵）的突变株ＧＭＨ－９０８。以淀粉糖为碳源,生物素亚适量,摇瓶常温发酵产酸９５ｇ／Ｌ以上,高温发酵产酸７４．９ｇ／Ｌ,比出发菌株Ｔ６－１３分别提高２６．６７％和２２．９９％;工业生产常温发酵月平均产酸８５－８８ｇ／Ｌ,转化率５２－５４ｇ％,单罐最高产酸１０８ｇ／Ｌ,转化率５８％;高温发酵产酸达７６．５ｇ／Ｌ,转化率４９．５％。     

ENHANCED β-GALACTOSIDASE PRODUCTION OF Aspergillus oryzae MUTATED BY UV AND LiCl

In order to breed a high-yield β-galactosidase-producing strain, Aspergillus oryzae was used as the parent strain and mutagenized with ultraviolet (UV) and UV plus lithium chloride (LiCl), respectively. After being mutagenized by UV, the β-galactosidase activity of mutant UV-15-20 reached 114.08 U/mL, which revealed a 49.22% increase compared with the original strain. A mutant UV-LiCl-38 with high β-galactosidase activity (121.42U/mL) was obtained after compound mutagenesis of UV and LiCl; the β-galactosidase activity of this mutant was 58.82% higher than that of the parent strain. Subculture testing indicated that UV-15-20 and UV-LiCl-38 had good hereditary stability and may be ideal strains for the production of β-galactosidase. Additionally, it was demonstrated that compound mutagenesis with UV and LiCl is an effective mutation method for breeding industrially interesting strains.     

黄霉素高产菌株的选育

目的:为了获得黄霉素高产菌株。方法:进行了一系列的诱变筛选。以加纳链霉菌(Streptomyces ghanaesis)SgWE-11为出发菌株,采用紫外线诱变,以其自身代谢物黄霉素作为筛选因子。结果:获得一株遗传稳定且黄霉素发酵效价比出发菌株高出170.25%的菌株。对该菌株采用亚硝酸诱变,并以链霉素作为筛选因子时得到一株效价值为875u/mL的高产菌株SgWE-25,比出发菌株SgWE-11提高了4.4倍。传代结果表明,在传代的同时结合自然分离,可以保持稳定的产抗特性。     

Gluconic acid production by Aspergillus niger mutant ORS-4.410 in submerged and solid state surface fermentation

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.     

Strain improvement of Aspergillus niger for the enhanced production of asperenone

The enhancement of production of asperenone (Fig. 1), an inhibitor of lipoxygenase and human platelet aggregation from Aspergillus niger CFTRI 1105, was achieved by UV and nitrous acid mutagenesis. Nitrous acid mutants exhibited increased inhibitor production when compared with UV irradiated mutants. I N 41 a first-generation nitrous acid mutant produced 5.1 fold increased asperenone over parent strain. Mutant II N 31 obtained by second-generation nitrous acid treatment produced 60.3 mg asperenone/g biomass, which was 131 fold increase when compared to first generated mutant I N 41 and 670 fold increase over the parent strain. This mutant was stable for several generations on production medium.     

UV+MW复合诱变结合抗性突变筛选替考拉宁高产菌株

采用微波照射(MW)、紫外照射(UV)和MW+UV处理技术,对替考拉宁产生菌AT-92的孢子进行诱变,诱变处理的孢子悬液涂布在含替考拉宁致死浓度的培养基平板上培养,获得替考拉宁抗性突变株,通过摇瓶发酵对替考拉宁抗性基因突变株进行筛选,获得一株遗传性状稳定的替考拉宁高产菌AT 92-52-37菌株,其产替考拉宁能力比出发菌株的提高5倍。     

紫外线诱变原生质体选育核黄素高产菌株

以产核黄素生产用菌——阿舒假囊酵母RS-89为出发菌株,用对致期生长的菌丝体,经0.5%蜗牛酶+0.5%纤维素酶作用2h可获得大量原生质体,其再生率为6.1%。对经UV诱变的原生质体再生株进行初筛、发酵复筛,从中获得了菌落大、色素深、产量高于出发菌株30%的高产稳定株——UP-91。     

柱晶白霉素产生菌的选育：耐磷高产突变株的分离

柱晶白霉素产生菌──北里链霉菌（Ｓｔｒｅｐｏｍｙｃｅｓ．Ｋｉｔａｓａｔｏｎｅｓｉｓ）,通过紫外线处理和高浓度磷酸盐平板上选择分离到突变株ＵＤＰ１－２,在正常发酵培养基条件下摇瓶发酵柱晶白霉素超产可达１８．６％。而且变株的菌落形态与亲本菌株差异较大。     

抗性突变他克莫司高产菌株的选育

研究利用核糖体工程育种方法结合紫外诱变处理产他克莫司链霉菌SIIA-9818,以期筛选得到发酵水平有较大提高的新菌株。首轮采用链霉素抗性筛选,第二轮组合链霉素和利福平抗性结合紫外诱变育种,进一步巩固育种成效。采用链霉素抗性诱变得到突变株T-122,其气生菌丝丰满程度明显好于原对照株,发酵效价提高22.8%;采用组合链霉素和利福平抗性结合紫外诱变T-122,得到多株高产菌株,其中H-493发酵水平较原出发菌株提高82.6%;在50 L发酵罐通过增大搅拌转速,使菌种H-493发酵单位进一步提高31.0%。本方法简单经济,得到的突变株发酵单位显著提高,组分无明显变化,传代稳定。     

紫杉醇高产菌株的原生质体诱变选育及其遗传变异初探

以紫杉醇产生菌NCEU_1为出发菌株,分别采用紫外线和紫外线与氯化锂复合诱变方法对其原生质体进行诱变,获得了两株高产紫杉醇的突变株———UV4 0 - 1 9和UL50 - 6 ,其紫杉醇产量从出发菌株的314 0 7μg L分别提高至376 38μg L和392 6 3μg L ;同时,又采用RAPD和同工酶技术对出发菌株NCEU_1与两高产株UV4 0 - 1 9和UL50 - 6 间的遗传差异进行了研究。结果表明,出发菌株与诱变菌株之间以及两诱变菌株之间都存在明显差异,为进一步研究与紫杉醇合成相关基因及诱变株产量提高的分子机制奠定了基础     

以脂肪酶为指标筛选赤霉素高产菌株的研究

以藤仓赤霉菌978对978#菌丝机械断裂后,采用紫外(30W,20cm)诱变处理60s,以脂肪酶活性为初筛指标筛选得到4株产赤霉素效价比出发菌株高的突变株,其中菌株GL-2在添加3%豆油的发酵培养基中产赤霉素能力比菌株978#在全淀粉发酵培养基发酵产素能力提高了1.2倍.调整补油工艺后,菌株GL-2产素能力进一步提高到...