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在已获得Spinigerin α抗菌肽摇瓶发酵条件的基础上,对其在50 L发酵罐中的初始甘油质量浓度、补料方式、甲醇与山梨醇混合比例、诱导温度、诱导pH值和诱导时间进行优化,并对诱导阶段甲醇与山梨醇混合体积比、诱导温度和诱导pH值进行正交试验。结果表明:甘油初始质量浓度10 g/L、补料方式为变速补料、甲醇与山梨醇混合体积比1∶1、诱导时间96 h、诱导温度24 ℃、诱导pH 5.0。在此最佳发酵条件下,50 L发酵罐的Spinigerin α抗菌肽产量较摇瓶条件提高20%。 相似文献
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葡萄糖流加方式对黄色短杆菌生产L-亮氨酸的影响 总被引:1,自引:0,他引:1
利用30 L发酵罐,研究了黄色短杆菌TK0303生产L-亮氨酸的发酵工艺。考察了初始葡萄糖浓度和发酵过程中3种补料策略(分批间歇流加补料、恒葡萄糖浓度流加补料和DO-在线识别流加补料)对菌体生物量、L-亮氨酸产量、副产物含量及糖酸转化率的影响。最终确定:分批补料发酵的初始葡萄糖浓度为60 g/L,葡萄糖补加采用DO-在线识别流加方式。根据溶氧响应信号的特征反馈控制葡萄糖的流加速率,可实现葡萄糖的限制培养,有效减少了发酵副产物的含量,菌体生物量和L-亮氨酸产量得到显著提高,分别为21.8 g/L和41.3 g/L,且糖酸转化率高达22.4%。 相似文献
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在2.5 L发酵罐中,对重组解脂酵母(Yarrowia lipolytica)PGC11505的琥珀酸发酵条件进行系统优化。发酵罐转速、通气量、初始甘油质量浓度、蛋白胨质量浓度、发酵罐的pH值设置经过优化后,琥珀酸的产量得到明显提高。发酵罐的转速600 r/min好于400 r/min,琥珀酸产量较之提高了1倍。通气量为1.0 vvm时最佳,较低时(0.5 vvm)溶氧不足、通气量较高时(2.0 vvm)溶氧过多,造成能源浪费。初始甘油质量浓度为100 g/L能保证菌体较好的生长,并且发酵较充分,琥珀酸产量达到21.0 g/L。蛋白胨的质量浓度为10.0 g/L比较适宜。发酵罐的不同pH值比较结果为,不控制pH值的自然发酵能获得最高的琥珀酸产量和产率,分别为26.3 g/L和0.27 g/g。依据以上确定的最适发酵条件进行不控制pH值的补料-分批发酵138 h,经过两次补料共消耗192.5g/L甘油,合成46.9 g/L琥珀酸,产率为0.24 g/g,生产率为0.34 g/(L·h)。琥珀酸的产量是优化初的5.7倍。 相似文献
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在优化了批式发酵条件的基础上,通过对流加补料方式、补料速度等发酵过程的各种参数,包括产酸率、转化率、发酵周期等进行了研究,优化了L-鸟氨酸补料分批发酵的条件。在最优补料分批发酵条件下,发酵58 h,L-鸟氨酸产量达59.35 g/L,糖酸转化率达37.09%。发酵结果明显优于分批培养。 相似文献
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为了实现L-山梨糖的高效生产,利用代谢改造的手段构建获得一株过量表达山梨醇脱氢酶基因(sldhAB)的重组菌氧化葡萄糖酸杆菌(Gluconobacter oxydans SLDH)。利用海藻酸钠和硅藻土包埋法固定化细胞,并在1 L发酵罐中对发酵条件和补料策略进行了优化,通过对发酵过程中底物消耗进行数学模拟,最终建立了分批补料发酵工艺。研究发现,和野生菌相比,在1L发酵罐水平上重组菌L-山梨糖的产量提高了20.3%,且发酵周期缩短了1/3以上。利用固定化重组菌进行分批补料发酵可完成19 d的补料发酵,其L-山梨糖净累积量比野生菌提高了30.3%。 相似文献
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Kobayashi K Kuwae S Ohya T Ohda T Ohyama M Tomomitsu K 《Journal of Bioscience and Bioengineering》2000,90(3):280-288
The dynamic programming method was applied to obtain the optimal specific growth rate, mu, in the fed-batch fermentation using the recombinant human serum albumin (rHSA)-producing yeast, Pichia pastoris. Based on the relationship between the specific production rate, varrho, and the specific growth rate, mu, a simple mathematical model describing the growth and rHSA production was constructed and used for calculations. Two constraints, final volume and maximum methanol feed rate, were adopted for calculations and the optimal mu resulted as follows. That is, mu was initially at the maximum value, mu(max), then decreased gradually. Finally, mu decreased to the mu(min) that gave a maximum varrho. The decline of mu was revealed to be caused by the constraint for maximum methanol feeding rate, F(max), and F(max) was constant until mu decreased to mu(min). We tried to realize the optimal mu in the fed-batch fermentation by manipulating the methanol feeding rate and obtained it. However, the observed varrho was differed from the expected one. The discrepancy between the expected varrho and observed varrho after the change of mu suggests the inapplicability of the relationship between mu and varrho to dynamic situations where mu changes. To confirm this, simulation and fed-batch fermentation runs were carried out at a methanol feeding rate that would cause a continuous change in mu. The rHSA production was simulated well, suggesting the applicability of the relationship between mu and varrho in such situations. Discontinuity in the change in methanol feeding rate of the optimal feed pattern at the time mu changed is considered to be the cause for the discrepancy between the expected and observed varrho. Therefore, a new methanol feeding strategy that could mimic the changes in mu and varrho of the optimal strategy without a discontinuity in the feeding rate was sought using a mathematical model of fermentation by trial and error. This modification in the methanol feeding rate resulted in a considerably improved varrho and 18% increase in total rHSA production compared with those obtained by the optimal strategy. 相似文献
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在50 L发酵罐中采用4种补料培养方式对灵芝菌丝体液态深层发酵合成灵芝三萜进行比较。结果表明,通过补料可以明显地促进灵芝菌丝体的生长和灵芝三萜的合成,同时,不同的补料方式对菌丝体生长和灵芝三萜合成有不同的影响。采用指数补料方式可获得较高的菌丝体干质量,并提高灵芝三萜含量,与传统的发酵方式相比,采用此补料策略取得了较好的效果。发酵终点灵芝菌丝体干质量达到17.68 g/L,灵芝三萜含量达到4.58 g/100 g干菌丝体,分别比分批发酵提高了65.70%和100.88%。 相似文献
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Tashiro Y Takeda K Kobayashi G Sonomoto K Ishizaki A Yoshino S 《Journal of Bioscience and Bioengineering》2004,98(4):263-268
A pH-stat fed-batch culture by feeding butyric acid and glucose has been studied in an acetone-butanol-ethanol (ABE) fermentation using Clostridium saccharoperbutylacetonicum N1-4. The specific butanol production rate increased from 0.10 g-butanol/g-cells/h with no feeding of butyric acid to 0.42 g-butanol/g-cells/h with 5.0 g/l butyric acid. The pH value in broth decreases with butyric acid production during acidogenesis, and then butyric acid reutilization and butanol production result in a pH increase during solventogensis. The pH-stat fed-batch culture was performed to maintain a constant pH and butyric acid concentration in the culture broth, but feeding only butyric acid could not support butyric acid utilization and butanol production. Subsequently, when a mixture of butyric acid and glucose was fed, butyric acid was utilized and butanol was produced. To investigate the effect of the feeding ratio of butyric acid to glucose (B/G ratio), several B/G ratio solutions were fed. The maximum butanol production was 16 g/l and the residual glucose concentration in broth was very low at a B/G ratio of 1.4. Moreover, yields of butanol in relation to cell mass and glucose utilization were 54% and 72% higher in pH-stat fed-batch culture with butyric acid than that of conventional batch culture, respectively. 相似文献
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该研究以枯草芽孢杆菌(Bacillus subtilis)XGL为出发菌株,探究黄嘌呤和谷氨酰胺添加量及添加方式对其产腺苷的影响。结果表明,底物中添加100 mg/L黄嘌呤并在发酵16 h后持续向发酵液中流加3 g/L的黄嘌呤溶液200 mL可使腺苷产量达到34.4 g/L,相比于不流加黄嘌呤时腺苷产量(11.2 g/L)提高207%。在此基础上,再向底物中添加6 g/L谷氨酰胺,发酵32 h之后持续向发酵液中流加6 g/L的谷氨酰胺,腺苷产量达到45.8 g/L,相比于不添加谷氨酰胺腺苷产量(34.4 g/L)提高33%。因此,在B. subtilis XGL发酵过程中,可以通过底物添加和流加补料的发酵方式加入一定量的黄嘌呤和谷氨酰胺以提高腺苷产量。 相似文献
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Krairak S Yamamura K Irie R Nakajima M Shimizu H Chim-Anage P Yongsmith B Shioya S 《Journal of Bioscience and Bioengineering》2000,90(4):363-367
Yellow pigment production in exponential fed-batch cultivation of Monascus sp. was studied. Due to the difficulty of measuring the optical density for accurate determination of the cell concentration, a capacitance probe was employed on-line. The feed rate needed to keep the specific growth rate, mu, constant in fed-batch culture was determined on the basis of the cell concentration measured by the capacitance probe. Control of mu was improved by using updated information on the cell concentration compared with the simple feed-forward determination method using the initial cell concentration only. The highest specific pigment production rate was achieved with a mu of 0.02 h(-1) in the feeding phase. However, among several fermentation examined, the largest pigment production in the final step was obtained at a mu of 0.01 h(-1); in each case the same amount of substrates was used. An investigation of the optimal initial glucose concentration revealed that pigment production was maximum when the initial glucose concentration in the batch mode was 10 g/l and mu was 0.01 h(-1) in the fed-batch mode. It was also found that the pellet weight in the fermentation could be accurately estimated by image analysis. The ratio of the mycelium weight to the total cell weight estimated from information on the total cell weight and the estimated pellet weight was found to be more than 80%. However, no clear quantitative relationship could be discerned between the specific pigment production rate, rho, and the ratio of mycelium in the cell population. 相似文献
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以氨水为中和剂,替代CaCO3,对耐氨米根霉R.oryzaeJS-N0-2-02进行15L自动发酵罐的分批和分批补料发酵及其发酵动力学的初步研究,结果表明,降低起始糖浓度,产酸期补糖可明显提高菌体L-乳酸比生产速率和耗糖产酸能力,提高L-乳酸产量和纯度,降低残糖。在发酵起始时添加1 g/L CaCO3能进一步提高补糖发酵的L-乳酸比生产速率,增强发酵后期菌体耗糖产酸能力,从而进一步提高L-乳酸产量和纯度,降低残糖。发酵结果:起始糖浓度为120 g/L,25h时补糖使最终发酵总糖浓度达137 g/L,发酵培养60 h,L-乳酸产量可达101.8 g/L,纯度97.3%,菌体耗糖转化率76%,比生产速率0.27 g/g.h,残糖降至3 g/L。 相似文献