链霉菌和小单孢菌原生质体制备的一种改良法

冈见于1974年关于制备稳定的链霉菌原生质体使用的培养基和培养条件,原生质体再生为正常菌丝的方法,这种方法有时稍加修改,就可用作链霉菌原生质体融合,或遗传研究。尽管发现原生质体形成和再生频率是随着使用菌种不同而变化。虽然1981年Shirahara 等报导了一种新的再生方法,我们     

对渗透压不稳定的链霉菌用常规脱水再生平板会使原生质体再生频率大幅度下降

影响链霉菌原生质体再生频率有三大要素,即菌丝生长期,菌丝和原生质体再生培养温度、再生平板的脱水率和培养基成份。60-1与74-4为在南朝鲜土壤中分离得到的二株抗生素产生菌,用经典的岡西昌则和汤普逊的各种方法不能使其原生质体再生?匝榈?0-1株菌丝培养基应为TSB(Difco)加甘氨酸0.7%,28℃培养45小时;74-4株亦     

产黄青霉菌球状菌株原生质体的分离再生和融合

产黄青霉菌球状菌株原生质体的融合是用两株不同遗传标记的菌株作亲本,用玻璃纸平板培养菌丝体,在高渗透性稳定剂中用纤维素酶裂解菌丝细胞壁,制备高浓度(10~6～10~7/ml)原生质体悬浮液。 将原生质体悬浮液接种到高渗性再生培养基上,再生频率可达40％左右。作渗透处理后,测得菌丝断片含量在0.01～0.1％之间。 两菌株的原生质体以1∶1相混合,用分子量6000,30％聚乙二醇处理后,发生了原生质体间的凝聚。将混合物涂布在高渗性合成培养基上,产生了异核体菌落,频率为0.40％左右。将少量异核体分生孢子分离在菌丝生长培养基上后,产生了数量相仿的两亲本型分离子。将大量异核体产生的分生孢子接种到合成培养基上后,能得到少数原养型杂合二倍体,频率为0.035％左右,杂合二倍体纯化后,再以紫外线诱发,获得了以角变和斑点形式出现的二亲本型分离子。     

dauW基因对柔红霉素产量的影响

报道了先前克隆的柔红霉素产生菌天蓝淡红链霉菌(Streptomyces coeruleorubidus)dauW基因的过表达和阻断对柔红霉素产量的影响.通过原生质体融合将dauW表达质粒导入天蓝淡红链霉菌DM,所得重组菌DM-W1的柔红霉素产量无明显提高;而通过大肠杆菌-链霉菌接合转移获得的发生同源重组单交换的dauW阻断突变株DM-W2,柔红霉素产量达(192.0±61.6)μg/ml,且遗传稳定性好.试验结果表明,对dauW基因的阻断突变能明显提高柔红霉素的发酵单位.     

黑暗链霉菌原生质体制备、再生及其DNA转化条件的研究

利用CP培养基培养黑暗链霉菌 (Streptomycestenebrarius) 990 4,采用二级培养即首先在37℃培养 48h ,然后按 10 %的转种量转种于新鲜的培养基中 ,同时补加 2 %甘氨酸 ,2 8℃培养 2 0h ,收获的菌丝体对溶菌酶敏感。在适宜的酶解条件下可形成 4 6 2× 10 9/mL原生质体 ,再生率为18%。利用经修饰的质粒DNA转化冻存的原生质体获得成功 ,转化率为 10 3～ 10 4 / μgDNA。     

生米卡链霉菌DNA对北里链霉菌原生质体种间转化

采用SDS-苯酚法提取生米卡链霉菌DNA,同时以SDS处理生米卡链霉菌原生质体得到游离DNA。将提取DNA及游离DNA转化北里链霉菌原生质体,得到10~(-2)的转化率。转化子经发酵得柱晶白霉素,其产量比亲本高5.2倍,同时发现组份亦有所变化,A_5组份从9.1％提高到36.7％。     

普那霉素产生菌的原生质体诱变育种

普那霉素产生菌始旋链霉菌（Streptomyces pristinaespiralis ）11．2在含0．5％甘氨酸的种子培养基中培养到对数生长期，收集菌丝体，经2mg／ml溶菌酶在30℃下作用90min可获得大量的原生质体，其再生率为5．1％。始旋链霉菌11.2原生质体经UV诱变并在含普那霉素的再生平板上筛选普那霉素抗性菌株，从中获得一高产：突变株始旋链霉菌ZP-07，普那霉素产量达到1．59g／L，比出发菌株提高101．3％。     

以脂肪酶活为指标快速筛选红霉素摇瓶发酵培养基

筛选红霉素链霉菌的摇瓶培养基需要将红霉素链霉菌在摇瓶中培养 6 d,然后测定红霉素链霉菌的效价 ,使用该方法需要至少 6 d的时间。而测定红霉素链霉菌在摇瓶中 d1脂肪酶的活力 ,并与对照样品比较 ,则只使用 1d的时间就能够推测红霉素链霉菌在 6 d后的效价 ,使用这一新方法 ,我们快速筛选出红霉素链霉菌 d1的酶活力比对照培养基高的两组新培养基 ,并且确认了新培养基中 6 d后的最高效价为 9313μg/ ml,比对照培养基提高了 78.38%。     

链霉菌抗生素生物合成基因的克隆策略

链霉菌具有许多不同于其它原核生物(如大肠杆菌等)的生物学特性,它们在生长过程中常伴有营养菌丝、气生菌丝和顶端结成孢子等形态分化类似霉菌的特性。链霉菌含有一个单环染色体,其基因组大小约10~4kb(近似大肠杆菌的3倍),在DNA组成中G+C含量高达70mol%以上,接近自然界中所观察到的上限。这些生物学上的差异使得链霉菌不能用其它遗传上了解得很清楚的原核系统进行研究,而必须自成研究体系。近年来,链霉菌自身的质粒和噬菌体载体系统的开发进展迅速。利用这些体系统已经分离获得了包括抗生素抗性基因、初级代谢方面的基因、各种输出酶基因、形态分化基因以及许多抗生素(如红霉素、四环素、放线紫红     

顶头孢霉菌原生质体制备及再生条件的改进

对头孢菌素Ｃ的工业生产菌顶头孢霉菌的原生质体制备、储存和再生的具体条件（如破壁酶、菌丝处理、菌龄、再生培养基、原生质体储存液等）进行了研究，优化各种条件后制备的原生质体的再生率最高可达６０％以上，这些改进了的条件也可供其它丝状真菌的原生质体制备和再生借鉴。     

Liquid culture enhances protoplast formation from the auxotroph (ser−) ofLentinula edodes

The optimal conditions for the production and regeneration of the protoplasts fromLentinula edodes were studied. Protoplast formation from the mycelia ofL. edodes which were cultured in liquid medium showed a significantly high yield compared with that of the mycelia which were cultured on cellophane covered agar media. A mixture of Novozyme 234 (15 mg/ml) and Cellulase Onozuka R10 (10 mg/ml) in 0.6 M mannitol (pH 4) was optimal lytic enzyme for the protoplast release. The optimal incubation time and mycelia age were 3.5-4 hours at 30 degrees C and 6-8 days, respectively. Regeneration frequency was 0.18% plated onto a medium containing 0.6 M sucrose, and 0.08% plated onto a medium containing mannitol. But hardly any regeneration was observed in the media containing NaCl, KCl, or MgSO(4). More than 90% of the protoplasts contianed nuclei and the nucleus number per protoplast was 1.1. The DNA content per nucleus was 5.1 pg. The diameter of the protoplast was 3-5 mum and it had a well defined cell structure.     

Studies on protoplast formation and regeneration ofGanoderma lucidum

To obtain a new strain ofGanoderma lucidum by protoplast fusion technique, its protoplast formation and regeneration were studied. Several factors affecting the protoplast formation and regeneration were investigated to find their optimum conditions. The mycelium was grown for four days on the cellophane membrane placed onG. lucidum complete medium (GCM). When various commercial lytic enzymes were examined for protoplast isolation, the combination of Novozym 234 and β-glucuronidase was found to be effective. An osmotic stabilizer, 0.6 M sucrose in 20 mM phosphate buffer pH 5.8, gave the highest yield of protoplasts. Three-hour incubation in shaking incubator was most suitable for releasing protoplasts. To increase the protoplast yield, pretreatment with 2-mercaptoethanol was carried out. The regeneration frequency in GCM containing 0.6 M MgSO₄·7H₂O was shown to be 0.66%.     

吸水链霉菌井冈变种原生质体的制备与再生

目的研究井冈霉素产生菌吸水链霉菌井冈变种的原生质体制备与再生的最佳条件。方法使用溶菌酶水解菌体细胞壁法,分别考察影响吸水链霉菌井冈变种原生质体的制备与再生的各种因素。结果在R2YE液体培养基中,一级菌丝体的最佳培养时间为24 h,二级菌丝体的最佳培养时间为16 h,最佳甘氨酸质量浓度为5 g.L-1,最佳溶菌酶质量浓度为2 g.L-1,最佳酶解时间为60 min,最佳再生培养基为R2YE,原生质体的再生率最高可达到15.79%。结论本实验确定了吸水链霉菌井冈变种的原生质体制备与再生的最佳条件,能够得到较高的再生率。     

Genetic transformation ofStreptomyces caespitosus

Genetic transformation ofStreptomyces caespitosus by plasmid pIj 702 was carried out. Optimal conditions for the protoplast preparation ofStreptomyces caespitosus, its regeneration, and its transformation by pIj 702 were evaluated. Addition of 2% glycine to the culture broth was optimal for protoplast yield. Formation and regeneration of protoplasts were most efficient when the mycelium were harvested at between late log and stationary growth phase. The regeneration frequency of the protoplasts was 15% when the protoplasts were regenerated on R2YE agar media containing 0.5M sucrose. Under the best condition for protoplats regeneration, the optimal transformation frequency was achieved with 40% polyethylene glycol (M.W. 4,000) treatment for 2 minutes.     

Plant regeneration from mesophyll and suspension protoplasts of Silybum marianum

Mesophyll protoplasts of six lines of Silybum marianum were enzymatically isolated from young leaves, embedded in sodium alginate, and cultivated in KM-medium. Division frequencies observed after ten days were strongly influenced by the protoplast density. When 5 x 10 (4)/ml protoplasts were plated, division frequencies of about 35% were obtained, with a protoplast population density of 1 x 10 (5)/ml division frequencies of about 75% resulted. Plant regeneration experiments undertaken with the protocalluses on medium containing BAP led to shoot formation in only two lines with regeneration frequencies of less than 1% in one (M 24) and up to 7% in a second line (M 2), respectively. However, when the protocalluses from line M 2 were treated with thidiazuron (TDZ) in a first culture step, and with BAP in a second step, the shoot formation frequency rose to 22%. Shoots were rooted on hormone free MS agar medium and transferred into soil where plants grew to maturity. Similar results were obtained when protoplasts of the line M 2, isolated from a suspension culture, were cultivated.     

红霉素链霉菌1—25菌株的特性研究

红霉素链霉菌14-74经一系列诱变筛选得到1-25菌株。本文报道1-25菌株培养特性,在摇瓶及生产罐中1-25菌株的生产能力比对照14-74菌株提高7％以上。发酵液中红霉素C的含量等于或小于对照菌株。高产的遗传性能稳定,对红霉素及丙醇的耐受力明显高于亲株,是一株优于14-74菌株的高产优质的抗反馈及抗阻遏的突变菌株。     

诺西肽产生菌活跃链霉菌的原生质体制备与再生

目的研究诺西肽产生菌活跃链霉菌的原生质体制备与再生的最适条件。方法使用溶菌酶脱去细胞壁制备原生质体,并考察原生质体制备和再生的各种影响因素。结果确定了原生质体制备的条件:一级培养采用种子培养基,培养30 h,转种量的体积分数为5%;二级培养采用R2YE培养基,培养时间为32 h,最适甘氨酸质量浓度为6.0 g.L-1,最佳溶菌酶质量浓度为1.5 g.L-1,酶解时间为60 min,原生质体再生率达到5.3%。结论上述条件为活跃链霉菌原生质体制备与再生的最适条件,该条件的建立为活跃链霉菌原生质体的诱变育种奠定了基础。     

Microbial transformation of aniline to acetaminophen

In order to obtain acetaminophen, a popular analgesic-antipyretic, through microbial p-hydroxylation and N-acetylation of aniline, various fungi and bacteria were screened. Among them,Streptomyces species were chosen for strain improvement by the use of interspecific protoplast fusion technique. Two interspecific fused strains were developed betweenS. rimosus (N-cetylation function) andS. aureofaciens (p-hydroxylation function) and also betweenS. lividans andS. globisporus. For efficient protoplast fusion and cell wall regeneration, various conditions were examined. In a typical experiment of mixedS. rimosus (pro⁻ his⁻) andS. aureofaciens (ilv⁻) protoplasts with 40% (w/v) polyethylene glycol 3350 (PEG) for 3 min gave 8.3×10⁻⁷ of fusion frequency. Treatment of mixedS. lividans (pant⁻) andS. globisporus (leu⁻) protoplasts with 50% (w/v) PEG for 3 min at 30°C gave 1.2×10⁻⁶ of frequency. Among the fused strains, up to 40–50% increase in p-hydroxylation power was observed. To investigate the possibility of plasmid involvement in p-hydroxylation of acetanilide, plasmid curing was attempted. We found that cells treated with acriflavine (at the frequency of 100%) and cells regenerated from protoplsts ofS. aureofaciens (2% frequency) lost their p-hydroxylation function.     

抗炎化合物EP产生菌的原生质体制备和再生工艺研究

目的系统研究 6 ,2 2 二烯 5 ,8 过氧麦角甾 3 醇 (EP)产生菌粘帚霉属真菌F菌的原生质体制备、分离与再生的条件。方法通过研究不同的酶解系统、酶解时间、再生培养基等多种因素 ,考察它们对该菌原生质体得率及再生率的影响 ;同时 ,采用高效液相色谱法测定原生质体再生菌株中EP化合物的含量。结果F菌菌龄为 6 0h时 ,以 0 .5mol/L的甘露醇配制成 2 %的蜗牛酶和纤维素酶混合溶液 ,2 8℃酶解 4h ,原生质体得量较高。而以0 .5mol/L的甘露醇为稳渗剂的再生培养基时 ,该菌的原生质体再生率较高。结论从代谢产物的角度对该菌原生质体制备和再生方法的可行性进行分析 ,并探讨此过程对F菌生物合成EP的影响 ,为进一步对该菌的分子遗传及高产菌株的选育创造条件。