聚类分析在红霉素摇瓶培养基无机盐分析中的应用

红色糖多孢菌的摇瓶培养基中使用不同有机氮源时红霉素的效价明显不同。通过对培养基中不同有机氮源所含无机盐的聚类分析。发现无机磷为影响红霉素效价的主要因素。培养基中无机磷含量高了会显著抑制红霉素的生物合成。     

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%。     

工业羽毛蛋白胨对红霉素基因工程菌ZL1004发酵过程的影响

本文在50L发酵罐上研究了工业羽毛蛋白胨对红霉素基因工程菌ZL 1004发酵过程的影响,结果表明发酵培养基中加入较多的羽毛蛋白胨不利于红霉素的合成,而加入适量的羽毛蛋白胨可有效提升整个发酵过程的摄氧率(OUR)水平、促进菌体对碳氮源的利用和红霉素的合成.进一步对培养基进行优化,采用0.6%羽毛蛋白胨、3.3%黄豆饼粉,发酵结束时红霉素效价达12487U/mL,A组分达9774μg/mL,分别比对照高18.21%和19.94%.利用显微图像及形态分析软件对发酵周期内的菌丝形态进行了跟踪定量研究,分析表明培养基中加入适量羽毛蛋白胨可优化菌丝形态,使其朝有利于红霉素合成的方向进行分化.     

均匀设计法优化柔红霉素发酵培养基

目的优化培养基,提高柔红霉素发酵效价。方法采用U1*0(108)均匀设计表进行均匀设计,用摇瓶发酵进行实验。结果使柔红霉素效价提高23%。结论使用均匀设计的方法可以较大幅度的提高柔红霉素发酵效价。     

利用均匀实验优化利福霉素SV发酵培养基氮源配比

应用均匀设计的方法对利福霉素SV发酵培养基中的氮源配比进行优化。研究了氮源中各成分对发酵效价的影响。确定各成分的最佳配比并用实验验证，使摇瓶发酵效价提高了10％以上。并对利福霉素SV产生菌在新、老培养基中的代谢特性进行了比较。     

红霉素发酵中连续补料的探讨

众所周知,在抗菌素发酵中菌丝生长和单位增长是密切相关的,没有足够量的菌丝,就没有高产抗菌素的物质基础,但菌丝陡长了,又影响抗菌素的产生。据报导在红霉素发酵中培养基里适于菌丝生长的氮源存在会抑制红霉素的合成,因此,要提高红霉素发酵产量,就必须严格控制各种发酵条件,特别是控制适宜的碳氮比,尽量做到既避免培养基中有过多的适于菌丝生长的氮源存在而又能维持菌丝正常代谢并在较长时间内菌丝量保持在适中的水平上。我们认为采用连续补料是解决这个问题的可行办法之一。本文报导红霉素发酵中将补料中的主要氮源—花生饼粉用A.S1398蛋白酶水解,取滤液,用连续流加代替一次性的大量补料的初步结果。     

增效依托红霉素胶囊中依托红霉素含量测定方法的探讨

目的：初步研究增效依托红霉素胶囊中依托红霉素的含量测定方法。方法：在样品不经分离的情况下,选择一定条件的培养基,缓冲液,药物浓度和检定菌,采用微生物效价法进行测定,结果：按本测定条件试验所得结果符合微生物效价测定法的要求。结论：按本建立的增效依托红霉素胶囊中依托红霉素含量的测定方法,可靠,准确,可作为该药质量控制的标准。     

螺旋霉素发酵培养基的改进

目前螺旋霉素发酵生产中培养基氮源多用鱼粉或黄豆饼粉。黄豆饼粉的优点是原材料质量稳定，染菌率低，但发酵效价相对较低。以鱼粉作氮源发酵效价相对较高，但鱼粉质量不稳定。本研究对培养基配方进行改进，在黄豆饼粉配方中加入动物蛋白ＮＹ，提高了发酵水平。后采用正交设计对黄豆饼粉、ＮＹ、葡萄糖、淀粉四个因素作三水平试验，最终得到最佳培养基配方：黄豆饼粉２％，ＮＹｏ．５％，淀粉７．０％，发酵效价为原配方效价的１４０．９２％，证实了新配方的可靠性。     

杆菌肽发酵过程中用毛细管电泳研究氨基酸代谢

应用毛细管电泳技术研究了杆菌肽发酵过程中游离氨基酸含量的动态变化及与发酵效价间的关系,并分析了杆菌肽发酵过程中的部分代谢流方向和规律。结果显示,在高浓度有机氮源的发酵培养基中,菌体代谢的EMP途径从3-PG向PEP转化过程的抑制被解除,同时TCA循环得到加强,这种有利的变化以及添加适量外源Lys,可以促进发酵前期菌体细胞的TCA循环通量,皆可提高发酵效价。     

磷酸三钙对红霉素生物合成的刺激作用

红霉素发酵培养基中用0.1％磷酸三钙代替原有的0.05％磷酸二氢钾,28℃培养8天,红霉素生物合成效价可提高5～9％。磷酸三钙可提供红霉素发酵过程中所必要的磷酸盐。     

Media optimization studies for Serratiopeptidase production from Serratia marcescens ATCC 13880

Production of an anti-inflammatory enzyme serratiopeptidase by fermentation with Serratia marcescens ATCC 13880 was studied to ascertain optimal nutritional conditions for large scale production. To study biosynthesis and production of serratiopeptidase by Serratia marcescens ATCC 13880, different physicochemical parameters were studied and optimized. The optimized medium contain, (g/l) glycerine 10.0, maltose 10.0 as carbon source, peptone 10.0 as organic nitrogen source, ammonium sulphate 10.0 as inorganic nitrogen source, dihydrogen phosphate 10.0, sodium bicarbonate 10.0, sodium acetate 10.0 as inorganic salt source, ascorbic acid 10.0 as stabilizer, distilled water 1000 ml and the optimized fermentation conditions were pH 7.0, temperature 37 degrees C and duration 24 hr. The modified fermentation medium produced 27.36 IU/ml of serratiopeptidase compared to 17.97 IU/ml in basal medium and the molecular weight of the purified serratiopeptidase was found to be 52 kD.     

Repression of beta-lactam production in Cephalosporium acremonium by nitrogen sources

A variety of inorganic and organic nitrogen sources were added to fermentation media to determine their regulatory effects on the production of beta-lactam antibiotics by Cephalosporium acremonium. (NH4)2SO4 at concentrations higher than 100 mM (1.3%) strongly inhibited beta-lactam production. L-Asparagine and L-arginine proved to be the best nitrogen sources tested for beta-lactam production. The optimum concentration of asparagine was 1.2%. Higher concentrations led to NH3 accumulation, increase in pH, and lower growth rates. Addition of tribasic magnesium phosphate [Mg3(PO4)2 X 8H2O] to the (NH4)2SO4-containing medium stimulated beta-lactam production markedly and ammonium repression of the ring-expansion enzyme was reversed. It appears that the ring-expansion step is a very sensitive part of beta-lactam biosynthesis in C. acremonium with respect to nitrogen source repression. Other enzymes may also be sensitive in view of the fact that nitrogen source derepression not only led to increases in cephalosporin C but, to a lesser extent, penicillin N and total beta-lactam titers.     

Effects of nitrogen sources on cell growth and production of nystatin by Streptomyces noursei

Cell growth and production of nystatin by Streptomyces noursei (ATCC 11455) were investigated on the three different nitrogen sources, ammonium sulphate, ammonium nitrate and sodium nitrate. S. noursei was able to utilise all of the three tested nitrogen sources for the growth and production of nystatin. High ammonium concentration had a negative effect on production of nystatin when phosphate and glucose was in excess. There was an increased production of nystatin when the cultures became ammonium limited. Cultivation with sodium nitrate as the nitrogen source resulted in a prolonged lag-phase for growth and about 50% lower final nystatin titres compared with cultures grown on nitrogen sources containing ammonium. Nystatin production was shown to be related to the specific growth rate, its production was increased at decreasing specific growth rates.     

vgb在红色糖多孢菌表达及生物活性的研究

利用基因工程技术对红色糖多孢菌进行改造，提高红霉素产率。用PCR技术克隆vgb，采用电穿孔法与红色糖多孢发酵菌染色体整合，鉴定采用Western blot与Southern blotting分析。VHb活性分析采用一氧化碳（CO）差示光谱法，红霉素效价测定采用管碟法。结果克隆了含vgb的红色糖多孢菌表达质粒（pBlueV），筛选了重组红色糖多孢菌株。与原始菌株比较，重组菌株细胞发酵密度分别为1．37与2．82，红霉素效价分别为3．8与5．1，相当于重组菌株提高红霉素体积产率约29％。重组红色糖多孢发酵菌提高了红霉素产率，对解决抗生素工业和基因工程菌高密度发酵有良好的应用前景。     

Influence of solvents on the variety of crystalline forms of erythromycin

The influence of the organic solvents widely used in the pharmaceutical industry (acetone, methylethylketone, ethanol, and isopropanol) both in the presence and in the absence of water on the crystallization behavior of erythromycin (Em), a clinically relevant antibiotic of the macrolide group, was investigated. It was observed that despite a high preference for water as a guest molecule, Em rather easily forms solvates with the organic solvents studied. Consequently, 4 distinct solvates of Em have been isolated by recrystallization: acetonate, methylethylketonate, ethanolate, and isopropanolate. It was established that in a pure organic solvent, or 1∶9 or 1∶1 water-organic solvent mixtures, the corresponding solvate is always crystallized. However, the recrystallization of erythromycin from 2∶1 water-organic solvent (excluding methylethylketone) mixture results in the formation of a crystal hydrate form. X-ray powder diffraction revealed the isostructurality of the solvates with acetone and methylethylketone. Thermogravimetric analysis showed that the loss of volatiles by all of the solvated crystals is nonstoichiometric. The desolvation behavior of the solvates with the organic solvents studied by means of variable-temperature x-ray powder diffraction indicates that in contrast to erythromycin dihydrate, they belong to a different class of solvates—those that produce an amorphous material upon desolvation.     

Effect of ammonium as nitrogen source on production of delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine synthetase by Cephalosporium acremonium C-10

Cephalosporin production by Cephalosporium acremonium strain C-10 was suppressed when the organic nitrogen source (1.2% L-asparagine) was replaced by 1.2% (NH4)2SO4. A higher level of (NH4)2SO4 (3.5%) led to even greater suppression. Ammonium repression was exerted on formation of delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine (ACV) synthetase, together with that of expandase; a lesser effect by ammonium was observed on cyclase production. Inhibition of ACV synthetase activity byammonium was also observed (ca. 50% inhibition at 250 mM NH4+).     

Effects of organic anions and vinblastine on biliary excretion of erythromycin in rats.

Since little is known about the mechanism of biliary excretion of cationic drugs, biliary excretion of erythromycin was studied in rats. Infusion of sulfobromophthalein and taurocholate significantly decreased biliary erythromycin excretion, whereas infusion of dibromosulfophthalein, cefpiramide, ursodeoxycholate-3-O-glucuronide and taurolithocholate-3-sulfate had no effect on biliary excretion of erythromycin. Vinblastine significantly inhibited biliary erythromycin excretion. Phenothiazine treatment significantly increased biliary erythromycin excretion. However, erythromycin infusion did not affect biliary vinblastine excretion. These findings indicate a multiplicity of biliary excretory pathways for organic cations; at least one additonal pathway may exist for organic cations apart from P-glycoprotein.     

The influence of different submerged cultivation conditions on mycelial biomass and protease production by Lentinus citrinus Walleyn et Rammeloo DPUA 1535 (Agaricomycetideae)

The influence of different carbon and nitrogen sources, pH of the culture medium, and temperature and period of cultivation on mycelial biomass production and protease activity by Lentinus citrinus DPUA 1535 were investigated in submerged culture. A 2(5) full factorial design with three central points was employed, and the results showed that at a significance level of 95% only nitrogen source and temperature were statistically significant for mycelial biomass production. On the other hand, for protease activity all factors and some interactions were significant, and the temperature and nitrogen source had the most significant effect. The best condition for mycelial biomass production (5.76 mg mL(-1)) and protease activity (32.3 U mL(-1)) was obtained in medium formulated with 0.5% soluble starch, 0.2% gelatin, pH 7.0, 25 degrees C, in 5 days.     

柚皮苷转化生成红花素及异红花素的研究

摘要：目的 利用一株日本曲霉，以柚皮苷为底物，转化生成红花素和异红花素并提高产物的发酵单位。方法 对 发酵培养基中氮源种类进行筛选并确定最适的添加浓度，考察微量元素对发酵的影响并确定最适添加浓度，降低溶解底 物的乙醇浓度并采用二次添加底物的方式等。结果 红花素发酵单位由66 μg/mL提高至389 μg/mL，异红花素发酵单位由 263 μg/mL提高至946 μg/mL。热豆粉是最佳氮源，添加浓度为0.3%；添加硫酸亚铁和氯化锰能够分别促进红花素和异红花素的 生成，其最适添加浓度分别为0.02%和0.01%；溶解底物的乙醇浓度由50%降低至26.6%，降低了乙醇对转化的不利影响；底物 添加次数由1次变为2次，有利于发酵单位的提高。结论 首次发现日本曲霉可直接转化柚皮苷生成红花素和异红花素，且柚皮 苷生物转化为红花素和异红花素的发酵单位较高。