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1.
Study of the effect of dissolved oxygen and shear stress on rifamycin B fermentation with A. mediterranei XC 9-25 showed that rifamycin B fermentation with Amycolatoposis mediterranei XC 9-25 needs high dissolved oxygen and is not very sensitive to shearing stress. The scale-up of rifamycin B fermentation with A mediterranei XC 9-25 from a shaking flask to a 15 L fermentor was realized by controlling the dissolved oxygen to above 25% of saturation in the fermentation process, and the potency of rifamycin B fermentation in the 15 L fermentor reached 10 g/L after 6-day batch fermentation. By continuously feeding glucose and ammonia in the fermentation process, the potency of rifamycin B fermentaion in the 15 L fermentor reached 18.67 g/L, which was 86.65% higher than that of batch fermentation. Based on the scale-up principle of constantly aerated agitation power per unit volume, the scale-up of rifamycin B fed-batch fermentation with continuous feed from a 15 L fermentor to a 7 m3 fermentor and further to 相似文献
2.
Study of the effect of dissolved oxygen and shear stress on rifamycin B fermentation with A. mediterranei XC 9–25 showed that rifamycin B fermentation with Amycolatoposis mediterranei XC 9–25 needs high dissolved oxygen and is not very sensitive to shearing stress. The scale-up of rifamycin B fermentation
with A. mediterranei XC 9–25 from a shaking flask to a 15 L fermentor was realized by controlling the dissolved oxygen to above 25% of saturation
in the fermentation process, and the potency of rifamycin B fermentation in the 15 L fermentor reached 10 g/L after 6-day
batch fermentation. By continuously feeding glucose and ammonia in the fermentation process, the potency of rifamycin B fermentation
in the 15 L fermentor reached 18.67 g/L, which was 86.65% higher than that of batch fermentation. Based on the scale-up principle
of constantly aerated agitation power per unit volume, the scale-up of rifamycin B fed-batch fermentation with continuous
feed from a 15 L fermentor to a 7 m3 fermentor and further to a 60 m3 fermentor was realized successfully. The potency of rifamycin B fermentation in the 7 m3 fermentor and in the 60 m3 fermentor reached 17.25 g/L and 19.11 g/L, respectively. 相似文献
3.
Strain improvement and medium optimization to increase the productivity of spiramycin were carried out. Of oil tolerant mutant strains screened, one mutant, Streptomyces ambofaciens XC 2-37, produced 9% more spiramycin than the parent strain S. ambofaciens XC 1-29. The effects of soybean oil and propyl alcohol on spiramycin production with S. ambofaciens XC 2-37 were studied. The potency of S. ambofaciens XC 2-37 was improved by 61.8% with addition of 2% soybean oil in the fermentation medium and 0.4% propyl alcohol at 24 hours after incubation. The suitable time for feeding propyl alcohol is at 24 hours after incubation in flask fermentation and at 20 hours after incubation in fermentor fermentation. The new process with S. ambofaciens XC 2-37 was scaled up for industrial scale production of spiramycin in a 60 m3 fermentor in Xinchang Pharmaceutical Factory, Zhejiang Medicine Company, Ltd., China, and the potency and productivity of fermentation were improved by 42.9%. 相似文献
4.
INTRODUCTION which the hydroxyl group is acetylated, and spi- ramycin III in which the same position is propio- Spiramycin belongs to the macrolide antibi- nylated (Omura et al., 1979). The addition of short-otics group. The molecular structure of spiramycin chain fatty acids stimulates the production of spi-consists of a 16-membered branched lactonic ring … 相似文献
5.
Strain improvement and medium optimization to increase the productivity of spiramycin were carried out. Of oil tolerant mutant
strains screened, one mutant,Streptomyces ambofaciens XC 2–37, produced 9% more spiramycin than the parent strainS. ambofaciens XC 1–29. The effects of soybean oil and propyl alcohol on spiramycin production withS. ambofaciens XC 2–37 were studied. The potency ofS. ambofaciens XC 2–37 was improved by 61.8% with addition of 2% soybean oil in the fermentation medium and 0.4% propyl alcohol at 24 hours
after incubation. The suitable time for feeding propyl alcohol is at 24 hours after incubation in flask fermentation and at
20 hours after incubation in fermentor fermentation. The new process withS. ambofaciens XC 2–37 was scaled up for industrial scale production of spiramycin in a 60 m3 fermentor in Xinchang Pharmaceutical Factory, Zhejiang Medicine Company, Ltd., China, and the potency and productivity of
fermentation were improved by 42.9%. 相似文献
6.
以紫外线为诱变剂,用庆大霉素产生菌JY1-12为出发菌株,选育出性能优良的菌株JY3-5.经正交试验确定其最佳发酵培养基,研究了最佳发酵温度和初始pH值,使其摇瓶效价提高35.1%;30m3灌放大试验,比出发菌株效价提高19.2%. 相似文献
7.
《天津大学学报(英文版)》2017,(6)
As a kind of aerobic bacteria, Saccharopolyspora spinosa exhibits a high demand for oxygen. In the fermentation process, the methods of increasing ventilation and improving agitation speed are usually adopted to achieve higher values of dissolved oxygen. These methods decrease the efficiency of spinosad biosynthesis.In this study, an improved reactor was designed to solve these problems. The exhaust gas reflux device, impellers,and baffles were improved. Furthermore, we established the kinetic models for the cell growth, substrate consumption and spinosad generation in batch fermentation process. The simulation results were in good agreement with the experimental data. Spinosad production reached 583.86 mg/L after employing the suitable feeding strategy by fed-batch fermentation in the improved reactor, whereas it was only 157.01 mg/L before optimization. The method described can provide insight to strengthen spinosad production and can be extended to the culturing process of filamentous aerobic bacteria. 相似文献
8.
INTRODUCTION Butyric acid has several potential applications in industry. Its applications in the foodstuffs and beverage industries are widespread. It may be used as the pure acid in the dairy industry, or in the form of esters as a food additive to increase fruit fragrance. Furthermore, butyric acid could also have some important physiological functions. For example, butyric acid esters are the character-impact flavors in tropic fruits and dairy products (Centeno et al., 2002; Watson e… 相似文献
9.
The production of butyric acid by Clostridium butyricum ZJUCB at various pH values was investigated. In order to study the effect of pH on cell growth, butyric acid biosynthesis and reducing sugar consumption, different cultivation pH values ranging from 6.0 to 7.5 were evaluated in 5-L bioreactor. In controlled pH batch fermentation, the optimum pH for cell growth and butyric acid production was 6.5 with a cell yield of 3.65 g/L and butyric acid yield of 12.25 g/L. Based on these results, this study then compared batch and fed-batch fermentation of butyric acid production at pH 6.5. Maximum value （16.74 g/L） of butyric acid concentration was obtained in fed-batch fermentation compared to 12.25 g/L in batch fermentation. It was concluded that cultivation under fed-batch fermentation mode could enhance butyric acid production significantly （P〈0.01） by C. butyricum ZJUCB. 相似文献
10.
本文介绍了菌种特性,底物浓度,溶氧水平,中间补料,pH值等因素,对庆大霉素C组份的影响,并做了粗浅探讨,得出既增加优良组份比值,同时又提高发酵单位的比较适宜的条件。 相似文献
11.
在前期研究的基础上,进行了强聚硒酵母发酵罐扩大培养条件的优化,最终确定发酵罐中最适发酵条件：麦芽汁1%,初始硒浓度为15μg/mL,在其发酵进入到对数生长期后再添加亚硒酸钠使之硒浓度达到25μg/mL,种子培养时间12 h,接种量为10%,培养温度28℃,通气量6 L/h,搅拌速度150 r/min,培养时间29 h。在此最优化条件下,酵母生物量达到8.05 g/L,硒含量达到1 003.19μg/g。 相似文献
12.
Response surface methodology （RSM） was used to optimize the fermentation medium for enhancing pyruvic acid production by Torulopsis glabrata TP19. In the first step of optimization, with Plackett-Burman design, ammonium sulfate, glucose and nicotinic acid were found to be the important factors affecting pyruvic acid production significantly. In the second step, a 23 full factorial central composite design and RSM were applied to determine the optimal concentration of each significant variable. A second-order polynomial was determined by the multiple regression analysis of the experimental data. The optimum values for the critical components were obtained as follows： ammonium sulfate 0.7498 （10.75 g/L）, glucose 0.9383 （109.38 g/L） and nicotinic acid 0.3633 （7.86 mg/L） with a predicted value of maximum pyruvic acid production of 42.2 g/L. Under the optimal conditions, the practical pyruvic acid production was 42.4 g/L. The determination coefficient （R^2） was 0.9483, which ensures adequate credibility of the model. By scaling up fermentation from flask to jar fermentor, we obtained promising results. 相似文献
13.
Studies on optimization of nitrogen sources for astaxanthin production by <Emphasis Type="Italic">Phaffia rhodozyma</Emphasis> 总被引：2，自引：0，他引：2
Ni H Chen QH Ruan H Yang YF Li LJ Wu GB Hu Y He GQ 《Journal of Zhejiang University. Science. B》2007,8(5):365-370
Fermentation ofPhaffia rhodozyma is a major method for producing astaxanthin, an important pigment with industrial and pharmaceutical application. To improve astaxanthin productivity, single factor and mixture design experiments were used to investigate the effects of nitrogen source on Phaffia rhodozyma cultivation and astaxanthin production. Results of single factor experiments showed nitrogen source could significantly affect P. rhodozyma cultivation with respect to carbon source utilization, yeast growth and astaxanthin accumulation. Further studies of mixture design experiments using （NH4）2SO4, KNO3 and beef extract as nitrogen sources indicated that the proportion of three nitrogen sources was very important to astaxanthin production. Validation experiments showed that the optimal nitrogen source was composed of 0.28 g/L （NH4）2SO4, 0.49 g/L KNO3 and 1.19 g/L beef extract. The kinetic characteristics of batch cultivation were investigated in a 5-L pH-stat fermentor. The maximum amount of biomass and highest astaxanthin yield in terms of volume and in terms of biomass were 7.71 mg/L and 1.00 mg/g, respectively. 相似文献
14.
通过单因子实验,筛选得到了适合大豆疫霉拮抗细菌B048液体发酵的最佳碳源为玉米粉,最佳氮源为豆粕,最佳无机盐离子为氯化钠。通过正交实验确定了该培养基的最佳配比为：玉米粉5g／L、豆粕15g／L、氯化钠10g／L。在确定适合该菌株的培养基组分基础上,对其培养条件进行优化,结果表明：初始pH值为6．0,培养时间为48h,转速为180r／min时为该菌株的最佳培养条件。 相似文献
15.
玉米浆作为氮源对透明质酸发酵的影响 总被引：1，自引：0，他引：1
采用玉米浆替代牛肉膏和蛋白胨作为氮源,在摇瓶和30 L发酵罐中进行透明质酸发酵,分析测定了直接利用玉米浆作为氮源和玉米浆酶解液作为氮源两种情况下透明质酸的发酵产量。结果表明,透明质酸产量太低,玉米浆不适合作为透明质酸发酵的氮源。 相似文献
16.
柑桔果醋发酵用醋酸菌筛选及特性研究 总被引：1，自引：0，他引：1
程世春 《四川教育学院学报》2010,26(6):45-46,57
从水果中分离得到41株醋酸菌,经过初筛和复筛产酸实验,筛选到一株高产醋酸菌株Acl．3,该菌以桔汁和桔皮为原料,产酸量分别为38．35g／L和38．46g／L,并对Acl．3菌株的培养及柑桔果醋酿制特性进行了研究。 相似文献
17.
本文介绍了发酵过程中氧传递的各种阻力,分析了影响发酵溶氧的因素,提出了有效改善和提高发酵过程中溶解氧浓度的方法和途径。 相似文献
18.
阿维拉霉素（卑霉素）是由绿色产色链霉菌（Streptomyces viridocbromogene,sv）发酵得到的寡糖类抗生素。本文研究了碳源,主要是葡萄糖和可溶性淀粉对阿维拉霉素产量的影响。葡萄糖是SV快速利用的碳源,研究发现大于20g/L的初始葡萄糖浓度强烈抑制阿维拉霉素的积累,可溶性淀粉是促进产物积累的有效碳源,但高于40g/L的初始可溶性淀粉浓度影响其转化率。在此基础上,设计碳源补加工艺,提高了阿维拉霉素的产量,其中以可溶性淀粉为基础碳源,培养过程中补加葡萄糖,培养240小时,阿维拉霉素的产量达到1926μg／ml。 相似文献
19.
探讨了溶氧对彭泽鲫(Carassius auratus var.Pengzesis)部分血细胞指标的影响.结果表明:在溶氧含量为5.76～8.00mg/L时,其血液中的红细胞数量是217～224万个/mm3,水中溶氧含量处于最佳溶氧状态下为7.00～8.00mg/L时,彭泽鲫血液中的白细胞表现较为稳定,在6 125～6 625个/mm3.本研究发现彭泽鲫在缺氧的情况下(Do:0.64～1.92mg/L),嗜中性细胞数量最多为47.63%,显著高于适氧条件下(Do:5.76～8mg/L)的嗜中性细胞数量(P<0.05),而在过氧的情况下(Do:8.96～16mg/L)其嗜中性细胞数量为31%,显著低于适氧条件下(Do:5.76～8mg/L)的嗜中性细胞数量(P<0.05). 相似文献
20.
利用流式细胞术对毕赤酵母发酵过程中胞内活性氧（ROS）的变化进行定量检测和分析,建立发酵过程单位细胞胞内ROS的相对含量以及单位体积细胞胞内ROS相对含量的计算方法,分析ROS积累对毕赤酵母细胞活力的影响,研究结果表明：在甲醇流加阶段,单位细胞的DCF（2′,7′-二氯荧光黄）染色平均荧光强度随着时间的增加而增加,即单位细胞胞内ROS的含量在甲醇流加阶段一直增加,细胞内产生持续的氧化压力,导致部分细胞死亡;单位体积酵母细胞的胞内ROS含量在甲醇流加阶段保持在一个相对稳定的范围。 相似文献