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考察了甘蔗糖蜜替代昂贵葡萄糖作为碳源、乳清粉替代大部分酵母粉作为氮源时,对Actinobacillus succinogenes NJ113发酵制备丁二酸的影响。血清瓶厌氧发酵结果证明：对照组（葡萄糖40 g/L）的丁二酸产量仅为26.04 g/L,而以糖蜜为碳源（以总还原糖计算为40 g/L）时,丁二酸产量达到28.27 g/L,比对照组提高了8.57%。在此基础上,以糖蜜为碳源、不同比例的乳清粉和酵母粉为混合氮源发酵制备丁二酸,确定了糖蜜、乳清粉和酵母粉混合使用的最佳浓度分别为40 g/L、8 g/L和2 g/L。此外,在3 L发酵罐体系中添加40 g/L糖蜜、8 g/L乳清粉、2 g/L酵母粉进行发酵试验,实验结果证明：丁二酸终产量达到32.54 g/L,收率达到81.13%。 相似文献
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氧化还原电位调控对Actinobacillus succinogenes 厌氧发酵产丁二酸的影响 总被引：4，自引：0，他引：4
对氧化还原电位调控在产琥珀酸放线杆菌厌氧发酵产丁二酸过程中的代谢产物分布的作用进行了研究。在血清瓶发酵培养过程中,筛选出对发酵过程无抑制作用的氧化剂铁氰化钾和还原剂二硫苏糖醇作为发酵体系的氧化还原电位调节剂。在3L发酵罐上利用铁氰化钾和二硫苏糖醇调节发酵体系氧化还原电位值在-100～-450mV,结果表明-350mV为菌体生长和产丁二酸的最佳电位,丁二酸生产速率由0.75g/(L·h)提高到1.18g/(L·h),产物丁二酸与副产物乙酸的质量浓度比由2.5提高到3.9。 相似文献
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Adam J. Hepburn Andrew J. Daugulis 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2012,87(1):42-50
BACKGROUND: Succinic acid (SA) is an intermediate in the production of commodity chemicals, but SA bioproduction has not yet been commercialized due to end product inhibition and high product separation costs. Two‐phase partitioning bioreactors (TPPBs) can increase volumetric productivity through in situ product removal, although SA uptake by polymers requires a pH below the pKA2 of SA (4.2). It was proposed to reversibly reduce the pH with CO2 sparging for absorption of SA, followed by nitrogen stripping to allow continued bioproduction after returning to metabolic pH levels. RESULTS: At 1 atm CO2 sparging lowered the pH of RO water to 3.8 but only to 4.75 in medium, requiring acid/base pH adjustment in subsequent experiments. Actinobacillus succinogenes was temporarily exposed to pH 4.2 for between 5 min and 4 h to observe the effect on subsequent growth; cells could grow after up to 4 h of low pH exposure, sufficient time for SA uptake. Because atmospheric CO2 could not adequately lower the pH of medium, a TPPB was operated with the pH being shifted using strong acid/base; SA was recovered in situ, however, the accumulation of salts hindered further cell growth. CONCLUSION: Several key elements of this novel processing strategy were successfully demonstrated, and work is continuing with high pressure CO2 to achieve the desired pH adjustment levels. Copyright © 2011 Society of Chemical Industry 相似文献
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对产琥珀酸放线杆菌（Actinobacillus succinogenes）GXAS137发酵木糖母液产丁二酸的条件进行优化,探索利用废弃木糖母液合成高附加值丁二酸的可行性。首先通过Plackett-Burman实验设计确定影响丁二酸发酵的显著因子,然后采用最陡爬坡实验逼近各显著因子的最优区域,最后通过Box-Behnken实验设计确定各因子的最优水平。影响木糖母液发酵产丁二酸的显著因子及最优浓度分别为：木糖母液64.75g/L,玉米浆15.71g/L,碱式碳酸镁46.39g/L。在最优发酵培养条件下,丁二酸产量达到38.01g/L,比优化前提高了20.7%,与模型预测值（38.41g/L）基本一致。进一步利用2L发酵罐进行了放大试验,发酵72h丁二酸产量最高可达48.99g/L,较厌氧瓶发酵提高了28.9%,丁二酸得率为0.80g/g总糖。结果表明,采用低价的木糖母液作为底物,可为未来低成本、高效产业化生产丁二酸奠定坚实的基础。 相似文献
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纤维素水解液中通常含有纤维二糖。本文考察了Actinobacillus succinogenes NJ113利用纤维二糖厌氧发酵生产丁二酸的能力,并利用蔗渣纤维素制备纤维二糖作为碳源用于厌氧发酵生产丁二酸。3 L发酵罐厌氧发酵结果显示：以35 g/L纤维二糖作为碳源发酵制备丁二酸,其产量为23.51 g/L,产率达到67.17%;用含有18 g/L纤维二糖和17 g/L其它糖类的蔗渣纤维素水解液作为碳源发酵制备丁二酸,丁二酸的产量和产率分别为20.00 g/L和64.73%。因此,Actinobacillus succinogenes NJ113具有较强的利用纤维二糖生产丁二酸的能力,而且利用废弃的纤维素制备纤维二糖作为碳源高效、经济地发酵制备丁二酸具有可行性。 相似文献
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产琥珀酸放线杆菌固定CO2制备丁二酸 总被引：2，自引：0，他引：2
在富含CO2的厌氧环境下,产琥珀酸放线杆菌NJ113固定CO2合成丁二酸作为主要代谢终产物。在5 L发酵罐探讨了培养条件对产琥珀酸放线杆菌NJ113固定CO2制备丁二酸的影响。考察了CO2供体形式、通气量、搅拌转速、培养温度和pH值对产琥珀酸放线杆菌NJ113厌氧发酵过程中CO2固定速率以及丁二酸产率的影响。结果表明,选择CO2气体作为CO2供体,CO2通气量为0.75 L/min,搅拌转速达到200 r/min,培养温度为37℃,NaOH调节pH值为6.6,可增加细胞内可利用的CO2。在此优化条件下培养,CO2固定速率达到0.6 g/(L.h),丁二酸产率达到1.61 g/(L.h)。 相似文献
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Hossein Nikakhtari Gordon A Hill 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2006,81(6):1029-1038
An external loop airlift bioreactor with a small amount (99% porosity) of stainless steel mesh packing inserted in the riser section was used for bioremediation of a phenol‐polluted air stream. The packing enhanced volatile organic chemical and oxygen mass transfer rates and provided a large surface area for cell immobilization. Using a pure strain of Pseudomonas putida, fed‐batch and continuous runs at three different dilution rates were completed with phenol in the polluted air as the only source of growth substrate. 100% phenol removal was achieved at phenol loading rates up to 33 120 mg h?1 m?3 using only one‐third of the column, superior to any previously reported biodegradation rates of phenol‐polluted air with 100% efficiency. A mathematical model has been developed and is shown to accurately predict the transient and steady‐state data. Copyright © 2006 Society of Chemical Industry 相似文献
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选用轻质粘土、硅藻土和蛭石等陶瓷原料,按一定比例进行配方和制作,研制成一种轻质生物膜陶瓷载体,比重仅有1.47g/cm^3,将其用于流化床生物反应器来处理有机废水,在较小的曝气量条件下即可呈现出良好的流态化.本研究重点考察了该载体挂膜特性,并和橡胶材料作对比研究,发现陶瓷载体上的生物膜仅经过一个批次的试验后对COD的去除率就达到80%以上,而橡胶载体上的生物膜却需要5个批次后才达到同样的去除率,同时发现两种载体的表面生成的生物膜群落有差异.经过连续试验发现,陶瓷载体表面的生物膜具有比较好的生物活性. 相似文献
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Serpil Ozmihci Fikret Kargi 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2009,84(1):106-111
BACKGROUND: Cheese whey powder (CWP) is a concentrated source of lactose and other essential nutrients for ethanol fermentation. CWP solution containing different concentrations of total sugar was fermented to ethanol in an up‐flow packed‐column bioreactor (PCBR) at a constant hydraulic residence time (HRT) of 50 h. Total sugar concentration in the feed was varied between 50 and 200 g L?1 and a pure culture of Kluyveromyces marxianus was used for ethanol fermentation of lactose. Variations of ethanol and sugar concentrations with the height of the column and with the feed sugar concentration were determined. RESULTS: Ethanol concentration increased and total sugar decreased with the column height for all feed sugar contents. The highest effluent ethanol concentration (22.5 g L?1) and ethanol formation rate were obtained with feed sugar content of 100 g L?1. Percentage sugar utilization decreased with increasing feed sugar content above 100 g L?1 yielding lower ethanol contents in the effluent. The highest ethanol yield coefficient (0.52 gE g?1S) was obtained with a feed sugar content of 50 g L?1. Biomass concentration also decreased with column height, yielding low ethanol formation in the upper section of the column. CONCLUSION: The packed column bioreactor was found to be effective for ethanol fermentation from CWP solution. The optimum feed sugar content maximizing the effluent ethanol and the specific rate of ethanol formation was found to be 100 g L?1. High sugar content above 100 g L?1 resulted in low ethanol productivities due to high maintenance requirements. Copyright © 2008 Society of Chemical Industry 相似文献
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E Erhan E Yer G Akay B Keskinler D Keskinler 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2004,79(2):195-206
Highly porous (85% void volume) polymer beads with interconnecting micro‐pores were prepared for the immobilization of Pseudomonas syringae for the degradation of phenol in a fixed‐bed column bioreactor. The internal architecture of this support material (also known as PolyHIPE Polymer) could be controlled through processing before the polymerization stage. The transient and steady state phenol utilization rates were measured as a function of substrate solution flow rate and initial substrate concentration. The spatial concentration of the bacteria on the micro‐porous support particles as well as within them was studied using scanning electron microscopy at various time intervals during the continuous operation of the bioreactor. It was found that although bacterial penetration into the porous support was present after 20 days, bacterial viability however, was compromised after 120 days as a result of the formation of a biofilm on the support particles. The steady state phenol utilization at an initial phenol concentration of 200 mg cm?3 was 100% provided that the flow rate was less than 7 cm3 min?1. Substrate inhibition at a constant flow rate of 4.5 cm3 min?1 was found to begin at 720 mg dm?3. The critical dilution rate for bacteria washout was high as a result of the highly hydrophobic nature of the support and the reduction of pore interconnect size due to bacterial growth within the pores in the vicinity of the surface of the support. Copyright © 2004 Society of Chemical Industry 相似文献
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俸志荣焦纬洲余丽胜李晓霞王永红刘有智 《过程工程学报》2016,16(3):533-540
综述了超重力过程工程装置结构近年来的研究进展,分析了各种装置的结构特点、适用场合,重点分析论述了撞击流-旋转填料床、折流板式超重力旋转床、分裂填料旋转填料床、多级雾化超重力旋转填料床、螺旋通道型旋转床等新型特殊装置的结构特点及优缺点. 认为优化进液方式、延长气液停留时间及针对性集成设计是未来超重力过程工程装置的发展方向. 相似文献
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Jirachote Phattaranawik Torove Leiknes 《American Institute of Chemical Engineers》2009,55(5):1291-1297
Alternative designs of an aerated moving‐bed biofilm reactor and a flat‐sheet membrane module for a biofilm membrane bioreactor process have been investigated to overcome a membrane clogging problem and to determine the performance of a new membrane module. Double‐deck aerated biofilm reactor with integrated designs of sludge hopper, thickener, and velocity‐zone concept for particle settlement was evaluated for the suspended solid control and removal. Hydrodynamics of bubbling, liquid, and solid particles were arranged in the bioreactor to obtain a particle settlement. New membrane modules used under low suspended solid environment having smaller membrane gaps were evaluated for filtration performance and clogging problems for long‐term operation. The average suspended solids concentration in the bioreactor effluent was 44.6 mg/L. Relaxation applied with the membrane module provided the most optimum result for fouling control, and no clogging problems in the modules were observed in the system after continuous operation of 3 weeks. © 2009 American Institute of Chemical Engineers AIChE J, 2009 相似文献
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César Huiliñir Estrella Aspé Marlene Roeckel 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2009,84(2):254-268
BACKGROUND: The modelling of simultaneous denitrification and methanogenesis (DM) in upflow packed‐bed biofilm reactors (UPBR) and the effect of inhibition by nitrogen compounds on methanogenesis has received little attention. This study evaluated the effect using a model that incorporates a pseudo‐two‐dimensional biofilm model. RESULTS: The model was validated through comparison with experimental data, and achieved deviations below 5% for the liquid and gas phases. The model indicated that biomass stratification exists throughout the reactor and within the biofilm interior. At C/N ratios close to the stoichiometric C/N ratio, the process achieves efficiencies greater than 70% for nitrogen load rate (NLR) < 270 mg NO3?‐N dm?3 h?1. At high C/N ratios (50 mg total organic carbon (TOC) mg?1 NO3?‐N), the process achieves efficiencies greater than 70% for organic load rate (OLR) < 83 mg TOC dm?3 h?1. CONCLUSION: The inclusion of the inhibition of methanogenesis by nitrogen compounds did not improve the predictions. Indeed, mass transfer in the biofilm was the phenomenon that most influenced the process. At C/N ratios close to the stoichiometric C/N ratio, process efficiency depends on the NLR; while at high C/N ratios, process efficiency depends on the OLR. Copyright © 2008 Society of Chemical Industry 相似文献
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Marcio A. Mazutti Giovani Zabot Gabriela Boni Aline Skovronski Débora de Oliveira Marco Di Luccio Maria Isabel Rodrigues Helen Treichel Francisco Maugeri 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2010,85(1):109-114
BACKGROUND: This work is focused on inulinase production by solid‐sate fermentation (SSF) using sugarcane bagasse, corn steep liquor (CSL), pre‐treated cane molasses, and soybean bran as substrates in a 3‐kg (dry basis) packed‐bed bioreactor. SSF was carried out by the yeast Kluyveromyces marxianus NRRL Y‐7571 and response surface methodology was used to optimize the temperature, air flow rate and initial mass of cells. RESULTS: The optimum inulinase activity (436.7 ± 36.3 U g?1 dry substrate) was obtained at 24 h at an inlet air temperature of 30 °C, air flow rate 2.2 m3 h?1 and 22 g of cells for fermentation. Inulinase productivity at these conditions was 18.2 U gds?1 h?1. Kinetic evaluation at the optimized conditions showed that the maximum inulinase production was verified at 24 h of fermentation. The carbon dioxide and the metabolic heat generation are directly associated with the consumption of total reducing sugars present in the medium. CONCLUSION: The high productivity achieved in this work shows the technical viability of inulinase production by SSF in a packed‐bed bioreactor. Copyright © 2009 Society of Chemical Industry 相似文献