表面活性剂PEG600对毒三素链霉菌发酵的影响

用PEG600代替毒三素链霉菌发酵培养基中的卵磷脂作为豆油的乳化剂，在其他发酵条件不变的情况下。PEG600较卵磷脂降低毒三素链霉菌发酵过程中溶氧水平，提高了豆油利用率，细胞向胞外分泌lipstatin的能力提高23．2％，lipstatin发酵效价提高35％。     

螺旋霉素链霉菌SPM^r—248的发酵特性研究

试验了乙酸钠、甲硫氨酸、乙醇、正丙醇、正丁醇和豆油对螺旋霉素链霉菌 SPM~r-248发酵的影响。结果表明在发酵培养48h 时补入1.0%豆油可使螺旋霉素摇瓶发酵效价提高49%。在30 m~3发酵罐上应用该工艺,发酵效价与原工艺比较可提高30%,发酵指数提高18.9%。     

豆油对螺旋霉素发酵的影响

以螺旋霉素链霉菌SPM1 1 0 8为出发菌株 ,经波长为 2 54nm、功率 30W的紫外诱变处理 50s,筛选豆油耐性突变株 ,得到一株螺旋霉素高产菌株SPM2 89,其发酵效价较出发菌株提高了 2 2 5 %。以此为试验菌株 ,采用含豆油培养基进行发酵试验 ,结果表明 ,豆油的最佳加入量为 2 0 % ,加入时间以 0～ 1 2h为宜。采用上述含豆油培养基并补加前体正丙醇 ,发酵效价比不添加前体提高 2 1 %。此工艺应用于 50m3发酵罐工业生产 ,月平均发酵水平较原工艺提高 30 %～ 50 % ,产品质量稍有提高     

毒三素链霉菌生产利普司他汀的发酵与提取工艺

研究了以豆油为主要碳源和能源的培养基中毒三素链霉菌的发酵代谢特性。在考察了乳化剂、温度等因素对利普司他汀生产的影响后，发现前期降低温度有利于保持菌种后期生产能力。最终变温发酵利普司他汀的产量达1．32g／L，比28℃恒温发酵提高了62％。并使用丙酮萃取与超声破碎细胞、乙酸乙酯萃取利普司他汀的提取工艺，简化了匀浆过程，提取效率为甲醇提取的3倍。     

透明颤菌血红蛋白基因(vgb)在那西肽产生菌—活跃链霉菌中的表达

目的将透明颤菌血红蛋白基因(vgb)整合到那西肽产生菌—活跃链霉菌(Streptomyces actuo-sus)的染色体上进行表达,从而提高菌体对溶解氧的利用,提高那西肽的发酵产量。方法采用分子生物学方法构建了携带vgb的重组质粒pZV02,采用接合转移的方法将其导入那西肽产生菌—活跃链霉菌中,采用抗生素抗性标记筛选法获得了基因重组菌株。结果在低溶氧的发酵条件下,重组菌株的那西肽产量显著高于对照菌株。结论 vgb在活跃链霉菌中的表达,可以改善菌体对溶解氧的利用,在低溶氧的条件下可以提高发酵产物那西肽的产量。     

氮离子注入土霉素产生菌的诱变育种

目的获得土霉素产生菌的高产菌株,提高发酵单位。方法用土霉素产生菌龟裂链霉菌经分离纯化的2810#菌株的分生孢子作处理样品,使用发射能量为15×103eV的氮离子束对其进行诱变处理,氮离子的注入剂量为每平方厘米注入2.0×1015个离子,分生孢子死亡率为98.2%。结果诱变处理后经摇瓶筛选得到1082#高产菌种,其摇瓶发酵单位提高11.2%,投入发酵生产后平均发酵单位提高8.9%。结论氮离子注入方法对提高龟裂链霉菌的产量正向突变频率有明显效果。     

劳伦链霉菌的诱变育种和发酵研究

劳伦链霉菌 (S.laurentii) ATCC312 5 5是含硫多肽类抗生素硫链丝菌肽 (Tsn)的产生菌。为提高Tsn产量 ,本研究采用 UV和 NTG对劳伦链霉菌野生型进行诱变 ,筛选抗 Cu2 、抗氯霉素或磷霉素超敏的菌株 ,经平皿初筛 ,摇瓶复筛 ,获得两株生产能力高于母株的菌株 ,即 UFOM30 2、UCL30 10。其 Tsn产量较野生菌株提高 5 8%和 38%。又经种龄、接种量、通风量、补料等发酵条件的探索 ,突变株 UFOM30 2最终 Tsn的产量可达 190 0 μg/ ml左右 ,比野生型活力提高一倍 ,达到工业生产的水平     

亚硫酸氢钠对龟裂链霉菌土霉素产量的诱变作用

1M亚硫酸氢钠pH5液诱变龟裂链霉菌(Streptomyces rimosus),其残存率曲线是单击式的;剂量试验表明:亚硫酸氢钠对龟裂链霉菌土霉素产量的诱变作用,以处理15分钟的结果为最好。龟裂链霉菌的不同菌株对亚硫酸氢钠的敏感性也不同。用亚硫酸氢钠处理龟裂链霉菌,其结果比甲基磺酸乙酯或羟胺的诱变效果好。已得到发酵单位提高4％以上的高产菌株,其菌落形态如草帽形,代谢与2-4032相似。     

一种新的β-内酰胺类抗生素SF-1623

抗生素SF—1623、SF—1623B、C是由教链霉菌(Streptomyces chartrensis)产生的一类新的β—内酰胺类抗生素。本文报道它的发酵、分离、鉴别和生物学性质。抗生素SF—1623发酵液组成为蔗糖2.0%、豆油2.0%、黄豆粉2.0%、鱼粉0.5%、硝酸钠0.15%、碳酸钙0.15%和硫代硫酸钠0.3%(pH7.0)。其中蔗糖和豆油对SF—1623     

盐霉素发酵工艺的优化研究

目的 优化盐霉素发酵工艺.方法 以白色链霉菌盐霉素-06-F2为产生菌,工艺条件为培养温度33℃,搅拌转速400 r/min,罐压0.05 Mpa,空气流量0.8 vvm,保证溶氧浓度40℅以上以及适当控制培养基中各成分含量.结果 与结论表明该工艺条件下发酵效价可以从61 400 U/ml提高到71 320 U/ml.     

响应面设计优化盐霉素发酵条件

利用SAS,Minitab和Design-Expert软件,采用Placket-Burman设计和中心组合设计对盐霉素的发酵条件进行优化.并运用响应面方法对盐霉素发酵条件进行进一步的分析,根据建立的多元二次方程确定其最佳水平,得到最佳的培养基:糊精4.5%,玉米浆0.6%,黄豆粉0.3%,氯化钾0.3%,硝酸铵0.3%,磷酸氧二钾0.04%,豆油10%,碳酸钙0.1%.培养条件为:接种量10%,pH 7.0,摇床转速为250r/min,培养周期10d.在此最优化条件下得到盐霉素发酵单位比优化前的产量提高了44%.     

沙利霉素抗肿瘤机制的研究进展

沙利霉素是从白色链霉菌发酵液中分离出的一种羧基聚醚类钾离子载体抗生素,广泛应用于家禽球虫病的防治。2009年首次发现沙利霉素对乳腺癌干细胞具有特异性抑制作用,此后的研究表明,沙利霉素能够有效抑制口腔鳞状细胞癌、卵巢癌、鼻咽癌、乳腺癌和肺癌等多种肿瘤细胞的增殖、转移和侵袭。沙利霉素通过靶向肿瘤干细胞、逆转肿瘤细胞耐药性、抑制肿瘤血管生成和上皮间充质转化、调节肿瘤细胞自噬发挥抗肿瘤作用。本文旨在对沙利霉素的具体抗肿瘤机制作一综述,为其在临床上进一步应用提供理论基础。     

HPLC determination of salinomycin and related compounds in fermentation media of Streptomyces albus and premixes

A rapid, sensitive and selective HPLC method with post-column derivatization was proposed for the determination of salinomycin and related products in fermentation broths and premixes. The solvent extracts of samples were analysed on a reversed-phase monolithic type column. The mobile phase consisted of methanol/zinc acetate (0.05 M) adjusted to pH 4.0 with acetic acid (85/15, v/v). Post-column derivatization with vanillin at 85 degrees C was used for simultaneous, selective detection of salinomycin at 520 nm and related products at 460 nm. Optimal ratio of mobile phase/reagent flow rate was 2:1. Alternatively, pre-column derivatization of salinomycin and related products with three different reagents (2,4-dinitrophenylhydrazine, p-bromophenacyl bromide and p-nitrobenzoyl chloride) was examined. Suitable derivates for HPLC separation and UV detection were prepared using p-nitrobenzoyl chloride. Extraction ability of various solvents for extracting of salinomycin and co-products from premix samples was also tested. Acetone, ethanol and pyridine were found to be the best extraction solvents for these compounds.     

LC determination of salinomycin in fermentation broths and premixes

A simple and rapid high performance liquid chromatography method for the determination of salinomycin in fermentation media of Streptomyces albus strains and in premixes has been developed. This method involves reverse-phase separation of the component analysed with UV detection at 210 nm using methanol and 0.2 M acetate buffer pH 5.8 (100:10, v/v) as the mobile phase. The reliability of the method was confirmed by validation. A linear relationship was obtained within range 0.2-2.0 mg ml(-1) (r=0.9999). The relative standard deviation of methods within-laboratory reproducibility was 1.6%. The estimated quantitation limit of assay was about 32.5 microg ml(-1). The method has been successfully used in the determination of salinomycin content in testing production processes and premixes of different commercial brands.     

An analysis of the chronic oral toxicity of polyether ionophore antibiotics in animals.

Feeding well-mixed ionophores to adapted cattle improves ruminal fermentation and growth rates. In nonruminants, growth is improved by reducing competing gastrointestinal microorganisms. Interactions of monensin with other drugs may be beneficial or toxic. Tiamulin and furazolidone potentiate monensin's negative effects. For example, monensin produces positive inotropy and cardiomyopathy dependent on calcium and extracellular sodium. Based on available toxicity data and derived no observable effect levels (NOEL) in the same species and across species, monensin was more toxic than salinomycin, lasalocid or narasin. Lasalocid was 5- to 10-fold less toxic to horses than is monensin. Based on available toxicity data and derived NOEL, lasalocid was less toxic than all ionophores except salinomycin. Very high levels of narasin caused death in sows, leg muscle weakness in turkeys, and cardiopulmonary clinical signs in 15% of the rabbits from Brazilian rabbit farms. Only salinomycin and lasalocid were less toxic than narasin. Salinomycin was the least toxic of all the ionophores. Maduramicin was the most toxic of all the ionophores. Nearly all maduramicin fed to poultry persists in litter (manure), making this poultry litter toxic if fed to cattle as a nitrogen source. While ionophore comparative toxicity was difficult to estimate, most cross-comparisons utilized NOEL within and across species. The relative toxicities of the ionophores from lowest to highest were salinomycin < lasalocid < or = narasin < or = monensin (but lasalocid < monensin) < maduramicin.     

响应面法优化替考拉宁发酵培养基及其扩大培养

摘要：目的 通过响应面法,优化替考拉宁发酵培养基,并对发酵工艺参数进行优化,来提高其发酵产量。方法 以游 动放线菌TC19-3p-103为试验菌株,采用单因素试验确定发酵培养基考察因素的参考范围;利用最陡爬坡试验确定响应面试验 的中心区域;利用Box-Behnken响应面法,确定了发酵培养基中的有机氮源最佳浓度组合;并对起始搅拌转速与通气量这两个 发酵工艺参数进行单因素考察;在发酵过程中,采用流加技术控制碳源浓度。结果 经优化的发酵培养基,其摇瓶产量提高了 31.6%;50L罐发酵工艺参数优化后,发酵水平达到8558 mg/L。 结论 优化后的发酵工艺,显著提高了替考拉宁的产量,为其 工业化生产奠定了基础。     

Salinomycin overcomes acquired tamoxifen resistance through AIB1 and inhibits cancer cell invasion in endocrine resistant breast cancer

Salinomycin is a monocarboxylic polyether ionophore isolated from Streptomyces albus. It has been widely used as an antibiotic in veterinary medicine in poultry. A recent study demonstrated that salinomycin selectively inhibits human breast cancer stem cells; one possible mechanism of tamoxifen resistance. Our results show that salinomycin is effective in inhibiting MCF‐7/LCC2 and MCF‐7/LCC9 cell lines which are well‐established endocrine resistant cells and has a synergistic effect in combination with tamoxifen using MTT proliferation assay. The inhibitory effect of salinomycin on the reduction of critical ER co‐activator; amplified breast 1 (AIB1) mRNA and protein expression is overcoming tamoxifen resistance . Moreover, salinomycin significantly inhibits cell invasion in Matrigel invasion assay. The effect was mediated at least in part by the decrease of matrix metalopeptidase 9 (MMP‐9) which is one critical enzyme facilitated in the cell invasion process. In conclusion, salinomycin should be developed as a novel agent used alone or in combination for endocrine‐resistant breast cancer.     

抗生素链霉菌合成喷司他汀发酵工艺的关键原料研究

目的 通过抗生素链霉菌对发酵培养基和发酵工艺优化,对发酵过程中所用的关键原料进行了研究,提高喷司他汀的发酵产量。方法 考察和评估抗生素链霉菌发酵生产喷司他汀发酵培养基中的关键原料,研究关键材料的供应商及用量,提高喷司他汀产量,于5000L发酵罐上进行发酵工艺验证试验。结果 喷司他汀摇瓶发酵单位达232mg/L,结果较原始工艺提高了28%;在5000L发酵罐发酵单位达210mg/L,较原始工艺提高了74%。 结论 控制发酵培养基中的植物油种类、来源和用量,能有效提高喷司他汀的生物合成。     

盐霉素自身抗性高产突变菌株筛选

目的筛选出具有自身次级代谢产物盐霉素(salinomycin)抗性并且遗传稳定性好的菌株,提高摇瓶效价。方法采用常规化学试剂甲基磺酸乙酯诱变处理盐霉素生产菌株Streptomyces albus S-13孢子,通过系列salinomycin浓度梯度平板进行筛选。结果获得了比生产对照菌株高38%的突变株S-E-6。传代实验表明:S-E-6具有较好的遗传稳定性。同时,通过对盐霉素梯度筛选突变株的单菌落直径与效价进行了统计分析,结果表明突变株菌落直径与盐霉素效价具有正相关特性,线性相关系数(R2)为0.95。     

嗜热脂肪芽胞杆菌生产1，6—二磷酸果糖的研究

研究了嗜热脂肪芽胞杆菌发酵生产1，6-二磷酸果糖（FDP）的工艺条件和工艺特点，采用活化培养工艺，改变菌体细胞透性和生理状态，获得高产率的FDP发酵液（产量为60mg/ml)。本法生产FDP具有副产物少，转化率高，发酵稳定的优点。