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.     

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。     

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.     

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。     

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.     

Genetic analysis on bioconversion of aniline to acetaminophen inStreptomyces fradiae

S. fradiae showed the highest acetanilide p-hydroxylation activity in the tested strains. AndS. fradiae was well characterized genetically, especially with respect to tylosin production. Two mutants, which lost hydroxylation, were isolated in 140 regenerated colonies from protoplasts. In restriction enzyme digesion of total DNAs, isolation of giant linear plasmid DNA and determination of antibiotic resistances to chloramphenicol, tylosin, hygromycin B and mitomycin C, any differences among mutants and a wild type strain were not detected. These facts suggest that lesion on 6,000 Kb chromosomal DNA was responsible for the lack of p-hydroxylation activity induced by protoplast formation and regeneration.     

刺糖多孢菌原生质体制备与再生条件优化

目的研究多杀菌素产生菌刺糖多孢菌(Saccharopolyspora spinosa)原生质体制备与再生的最佳条件。方法利用数理统计的方法研究了不同制备培养基、菌龄、甘氨酸浓度、溶菌酶处理条件以及再生培养基对原生质体制备和再生的影响,并考察了原生质体的适宜保藏温度。结果菌体在添加0.3%甘氨酸的EHC培养基中培养72h,用2mg/mL溶菌酶32℃酶解40min后,涂布在再生培养基R6上再生,原生质体制备率超过99%,再生数可达到107cfu/mL。刺糖多孢菌原生质体可置于4℃短期保存72h,长期保存需要放置于-80℃条件下。结论优化的结果为刺糖多孢菌原生质体融合育种和遗传转化体系建立奠定了基础。     

Enhancement of water-solubilities of protein-bound polysaccharides contained in the basidiocarps ofGanoderma lucidum by hydrolyzing with chymotrypsin

Optimum conditions for hydrolysis were investigated to enhance water-solubilities of protein-bound polysaccharides in the basidiocarps ofGanoderma lucidum by treating chymotrypsin. We also attempted withGanoderma lucidum residue remaining after extracting hot water-soluble components inGanoderma lucidum. After hydrolyzing under optimum conditions (20 ppm chymotrypsin, 2%Ganoderma lucidum or 6%Ganoderma lucidum residue, at pH 10 and at 40°C), the amounts of total protein and carbohydrate of hydrolysate were measured. Michaelis constant, K_m and maximum rate, V_max calculated by Lineweaver-Burk plot for the hydrolysis ofGanoderma lucidum were 1.73% and 0.073%/min respectively and those for hydrolysis ofGanoderma lucidum residue were 2.40% and 0.033%/min respectively. The amount of polysaccharide isolated fromGanoderma lucidum (100 g) treated with chymotrypsin was only 3.07 g, but significantly increased amount (14.34 g) of polysaccharides was isolated fromGanoderma lucidum residue (100 g) treated with chymotrypsin. The protein-bound polysaccharide was isolated from the non-hydrolyzed and hydrolyzed samlpe and molecular weights of the polysaccharide were measured by Sepharose CL-4B gel filtration.     

Conversion of water-insoluble components of the basidiocarps ofGanoderma lucidum to water-soluble components by hydrolyzing with chitinase

We investigated the optimum conditions for conversion of water-insoluble components of basidiocarps ofGanoderma lucidum to water-soluble components by hydrolyzing with chitinase. We also tried it withGanoderma lucidum residue remaining after extracting hot water-soluble components ofGanoderma lucidum. After hydrolyzing under optimum conditions (20 ppm chitinase, 2%Ganoderma lucidum or 6%Ganoderma lucidum residue, at pH 3 and at 35°C), the contents of total water-soluble components (polysaccharide or protein) were measured, and it was found that the contents of water-soluble components increased to 1.5～2.7 fold. Michaelis constant, K_m and maximum rate, V_max calculated by Lineweaver-Burk plot for hydrolysis ofGanoderma lucidum were 1.75% and 0.02%/min respectively and those for hydrolysis ofGanoderma lucidum residue were 53.15% and 0.53%/min respectively. The protein-bound polysaccharide was isolated after hydrolysis and molecular weights were measured by Sepharose CL-4B gel filtration and compared with the molecular weights of polysaccharide before hydrolysis.     

原生质体诱变及高通量筛选选育链霉素高产菌株

目的 通过诱变和筛选方法的研究，提高灰色链霉菌(Streptomyces griseus)生产链霉素的水平。方法 优化灰色链霉 菌的原生质体的生成和再生条件，并对得到的原生质体进行紫外诱变，然后利用微孔板高通量方式对获得菌株进行筛选。结果 经过诱变选育获得一株菌NP-11703，其链霉素产量在100L罐上比出发菌株提高了21.8%。结论 用紫外诱变原生质体，可以有 效提高灰色链霉菌产链霉素的能力。结合高通量筛选模型的应用，可大大加快高产菌株的筛选效率。     

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。     

红霉素链霉菌原生质体的形成和再生及其对紫外光的敏感性

红霉素链霉菌的菌丝生长在含有0.8％甘氨酸的S培养基中,对溶菌酶的作用敏感,通过酶解,并利用一个包含10mM-MgCl_2和25mM-CaCl_2的高渗培养基能使其菌丝脱壁形成10~(10)/ml的原生质体。 原生质体能再生细胞壁,回复成为一个完整的细胞。最佳条件时再生频率达90％左右。 利用紫外光对红霉素链霉菌的孢子及原生质体分别照射3分钟,其致死率分别为97.95％和98.81％。     

女贞子提取工艺的研究

目的 优化女贞子的最佳提取条件。方法 采用正交试验法设计实验,考察乙醇浓度、加醇量、提取时间和提取次数,通过齐墩果酸、特女贞苷含量测定及浸膏得率来确定最佳乙醇提取工艺;考察粉碎度对女贞子提取工艺的影响,比较女贞子提取液趁热过滤浓缩与静置24 h后过滤浓缩的结果差异,并比较女贞子醇提工艺和水提工艺的各项指标。结果 女贞子最佳提取工艺为加10倍量的70%乙醇,提取3次,每次1 h,提取液趁热过滤浓缩。结论 该优化提取工艺合理可行,更适合生产。     

赤霉素产生菌原生质体制备、纯化与再生工艺的研究

目的对赤霉素产生菌原生质体进行制备、纯化、再生工艺改进与完善。方法本文通过微孔滤膜作载体,在含甘氨酸的菌丝生长培养基固体平板上,培养取得幼嫩菌丝体,并对原生质体制备时的复合破壁酶液组分配比、酶解时间,原生质体纯化再生工艺进行了改进和完善。结果实验证明:①在幼嫩菌丝体的制备过程中,采用微孔滤膜平板法培养幼嫩菌丝体,易于控制菌龄,生长在微孔滤膜上的菌丝体不混杂有多余的培养基成份,不必经洗涤,可直接酶解,简化了实验步骤;②在原生质体制备过程中,采用以纤维素酶2%+蜗牛酶1%+果胶酶0.4%作为复合破壁酶液的组成,可使原生质体的释放量从105升至106;③在原生质体纯化过程中,采用先慢速离心沉淀,后洗涤滤除菌丝断片的操作方法,可使无壁娇嫩易碎的原生质体可依附菌丝断片作缓冲载体一起沉淀,有利于纯化收集到完整的原生质体,提高原生质体的活性再生;④在原生质体再生过程中,选用含有聚胨、酵母膏成份的RM再生培养基,可使原生质体的再生率达到16%以上。结论原生质体制备、纯化、再生工艺的改进与完善,确保了诱变育种基因突变后的遗传个体绝大部分都是纯合体,避免了高产性状经传代后水平回复的现象,为赤霉素理化诱变育种工作的顺利开展创造了良好条件。     

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。     

灵芝孢子油对大鼠肝纤维化的干预作用

目的 探讨灵芝孢子油对大鼠肝纤维化的影响。方法 选择40% CCl₄皮下注射诱导SD大鼠肝纤维化形成,造模同时用低、中、高剂量（0.33,0.67,2.00 g·kg^-1）灵芝孢子油灌胃干预（每组10只）,观察血浆谷草转氨酶（AST）、谷丙转氨酶（ALT）、丙二醛（MDA）、透明质酸（HA）和肝组织MDA、羟脯氨酸（HyP）等的变化,肝组织HE和Masson染色观察病理变化。结果 灵芝孢子油能显著降低CCl₄所致的肝纤维化大鼠血浆AST、ALT、MDA、HA水平（P<0.05）,降低肝组织HyP、MDA含量（P<0.05）,肝脏病理显示纤维化程度明显减轻（P<0.05）。结论 灵芝孢子油对CCl₄诱导的大鼠肝纤维化具有保护作用。     

The oxidative metabolism of dimemorfan by human cytochrome P450 enzymes

To characterize the human cytochrome P450 (P450) forms involved in dimemorfan oxidation (DFO), human liver microsomes, and recombinant P450s were investigated. Liquid chromatography-mass spectral analysis suggested that metabolite (M)1 ([M + H]⁺ m/z at 272.200) and M2 ([M + H]⁺ m/z at 242.190) were d-3-hydroxymethyl-N-methylmorphinan and d-3-methylmorphinan, respectively. Kinetic analyses of microsomal DFO showed that the substrate concentration showing a half-maximal velocity (S₅₀) of M1 formation was less than that of M2. Microsomal M1 and M2 formation activities correlated significantly with the CYP2D6 marker, dextromethorphan O-demethylation activity. The M2 formation activity was also correlated with the CYP3A4 marker, nifedipine oxidation activity. Microsomal M1 and M2 formation was most sensitive to the inhibition by a CYP2D6 inhibitor, paroxetine and a CYP3A4 inhibitor, ketoconazole, respectively. The immunoinhibition-defined P450 contributions indicated the participation of CYP2C9, CYP2C19, and CYP2D6 in the M1 formation and CYP2B6, CYP2C9, CYP2C19, CYP2D6, and CYP3A4 in the M2 formation. Among recombinant P450s, CYP2D6 had the highest intrinsic clearance with a K_m value of 0.02 mM in forming M1. CYP2B6, CYP2C9, and CYP2C19 had the K_m or S₅₀ values smaller than those (1 mM) of CYP2D6 and CYP3A4 in forming M2. These results indicated the participation of multiple P450 forms in DFO. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:1063–1077, 2010     

顶头孢霉229与12的分生孢子及原生质体的形成和再生

头孢菌素产生菌顶头孢霉菌株229的沉没培养或斜面培养都可形成分生孢子,并可用普通滤纸将它们与菌丝及节孢子分开,但是它们成活率极低.这种成活的分生孢子的数量与培养基成分有关.菌丝培养基成分对制备顶头孢霉原生质体有显著影响.用一种MM培养基培养的菌丝,不经巯基化合物预处理,酶解(1%纤维素酶)3小时后,可得到大量原生质体.原生质体的再生频率为1.8～4.6%.与分生孢子形成的菌落相比,原生质体再生菌落的产抗生素能力显示出较大的变异性.本文还讨论了山梨醇与Nikkomycin对菌丝生长形态及原生质体形成的影响.     

环孢菌素A两种不同产生菌原生质体的制备和再生

以环孢菌素A两种不同产生菌——雪白白僵菌和茄病镰刀菌为出发菌株，开展了原生质体制备和再生条件的研究，并分别实现了两个不同种的菌株原生质体再生。     

基因组重排选育麦迪霉素高产菌株

目的以生米卡链霉菌(Streptomyces mycarofaciens)突变株为研究对象,选育麦迪霉素高产菌株。探索并验证基因组重排技术在菌种选育中的重要作用。方法通过2轮多亲株灭活原生质体融合技术实现基因组重排。将来自不同育种方法的5株麦迪霉素高产菌株B64-5、01-GM-1、H-101、H-106和H-108作为第一轮亲本,在质量浓度为3 g.L-1溶菌酶3、2℃水浴60 min条件下制备原生质体,分别采用紫外线照射148 s和52℃加热60 min灭活原生质体,然后采用质量分数35%PEG 4000、37℃保温2 min诱导原生质体融合。融合子经过初筛和复筛,获得产量进一步提高的重组子作为亲本进行第二轮的多亲株灭活原生质体融合实验。用生物学方法测定麦迪霉素效价,用HPLC方法测定麦迪霉素A1含量。结果与结论经过2轮基因组重排实验成功选育出3株高产且遗传稳定的麦迪霉素生产菌株。其中1株菌株GSZ2-32发酵前补加前体X-1后摇瓶产量比原始出发菌株Streptomyces mycarofaciens var.464提高1.1倍,麦迪霉素A1(MDMA1)质量分数含量保持在80%以上。