Demineralization of glutamine fermentation broth by electrodialysis

The application of electrodialysis technology in demineralization of glutamine fermentation broth was studied. We used the one-dimension Nernst—planck equation to describe the process of demineralization of the glutamine fermentation broth system, did the theoretical calculation on the demineralization ratio and the loss rate of glutamine, and made a comparison with the experimental results. The results show: the one-dimension Nernst—Planck equation can describe the process of electrodialysis demineralization of the fermentation broth system, there is a little deviation between the result of the theoretical calculation and the experimental result, and the loss rate of glutamine in the experimental data is a little higher than that in the theoretical calculation. Moreover, we also investigated the change of the current efficiency of the simulation feed solution and fermentation broth in the electrodialysis along with the process of demineralization. The current efficiency decreases a little along with the process of demineralization, and the current efficiency in the fermentation broth is lower than that in the simulation feed solution.     

Microfiltration of Streptomyces rimosus: Cell Harvesting Process Studies

ABSTRACT

Process studies were carried out to investigate the feasibility of using tangential crossflow microfiltration to harvest antibiotic-producing cells such as Streptomyces rimosus from a whole fermentation broth. The microorganism was grown in a repeated batch fermentation up to the point of secondary mycelium formation in order to simulate broth age and mycelial morphology present in the terramycin production process. Cell separation was carried out in a Millipore Pellicon system equipped with a Durapore 0.45 μm membrane cassette and operated in a batch concentration mode. Permeate fluxes for untreated fermentation broth were measured and compared with those for broth that was pretreated by acidification—a typical process step used to improve antibiotic recovery. Acidification from pH 7 to 4 prior to filtration changed the cell morphology and significantly reduced the inlet feed pressure required to pump the broth. In addition, pretreatment enabled higher crossflow rates and higher steady-state fluxes to be obtained at lower transmembrane pressures. Permeate fluxes for the pH-treated fermentation broth increased with operating temperature but were independent of further changes in pH     

循环冷却水中生物粘泥偏高的原因及对策

从循环冷却水系统的微生物控制、生产工艺、现场操作及设备等几个方面分析了造成循环水中生物粘泥大量超标的原因;并且提出了更换新型杀菌剂,加强现场管理及消除设备缺陷等相应的对策措施。对策实施后,循环水中微生物得到有效控制,异养菌等细菌明显减少,达到≤10^3mL^-1,同时生物粘泥也大幅下降,达到≤3mL/m^3的指标要求。     

CNG und LNG aus biogenen Reststoffen – ein Konzept zur ressourcenschonenden Kraftstoffproduktion

A highly integrated process for the conversion of biogenic residues in combination with electricity from renewable sources to methane-based fuels was developed. Forest residues, straw and sewage sludge were identified as particularly relevant input feedstock. By combining gasification, high-temperature electrolysis and catalytic methanation, the biogenic carbon remains almost completely in the products. The matching temperature levels of the heat streams result in a very efficient process. The production costs are comparable to less resource-saving technologies and predictably lower than those of biomethane when plant capacities are increased.     

电驱动膜过程在氨基酸发酵液处理中的研究进展

在发酵法生产氨基酸的过程中,需要后续工艺对发酵液进行分离纯化以提取目标产物.电驱动膜过程正逐渐成为该领域研究与应用的热点.本文介绍了近年来国内外普通电渗析(ED)、双极膜电渗析(BMED)、离子取代电渗析(ISED)、电复分解反应器(BMT)等常见的电驱动膜过程在氨基酸发酵液处理中的研究进展,简述了常见的膜堆构型及其工作原理、特点与应用实例.分析表明电驱动膜过程可以实现混合氨基酸分离、无机盐脱除以及氨基酸的制备,膜堆结构、操作参数的优化以及新型分离膜的研究与应用可以提高过程性能.同时也指出目前该领域的研究尚处于实验室研究阶段,研究对象以模拟发酵液为主,规模化应用的报道还不多见.但是可以预见高效、环保的电驱动膜过程将会在氨基酸发酵液处理中发挥重要作用.     

Purification of recombinant human interferon gamma from fermentation broth using reverse micellar extraction: A process optimization study

In the present investigation, we have shown a single step purification of IFN-γ from the fermentation broth of recombinant Kluyveromyces lactis (K. lactis) strain, using cationic surfactant based reverse micellar extraction (RME) system. The forward and back extraction processes were optimized in order to improve the overall extraction process. 78%, 93% and 98% forward extraction efficiencies (FEE) were obtained after the process by using aqueous phase pH 12, 150 mM CTAB and 0.2 M NaCl respectively. Afterwards, back extraction efficiency (BEE) was maximized by the optimization of stripping phase pH, isopropyl alcohol (IPA) and potassium chloride (KCl) concentration by employing Taguchi’s method of orthogonal array. Stripping phase pH 7, 15% IPA & 0.8 M KCl were found to be the best possible parameters producing 83% BEE. The usage of IPA has proven to reduce the effect of micellar-micellar based interaction, which was reflected as an improvement in BEE. This study demonstrates that the reverse micellar system is a highly promising and efficient tool for the direct extraction of recombinant proteins from fermentation broth. Moreover, this system holds a high potential to be an integral part of the downstream process used in biopharmaceutical industry.     

槐糖脂发酵液预处理及不同结构槐糖脂的分离纯化

优化确定了槐糖脂（sophorolipids，SLs）的工业化生产过程中发酵液预处理及槐糖脂的分离纯化新工艺。对下层发酵液利用自然沉降法替代传统乙酸乙酯萃取法获得内酯型槐糖脂；对上层发酵液利用工业化生产中常用的板框过滤替代传统实验室离心法去除菌丝体，利用树脂吸附及超滤法除杂替代实验室及生产中常用的有机溶剂萃取法及醇沉法，获得高纯度的酸型槐糖脂产品。通过上述步骤的实施，实现了菌液的有效分离，成功获得了高浓度、高纯度的不同结构的槐糖脂产品。所得产品经槐糖脂含量测定及HPLC组成测定检验发现，产品标准达到市售标准，产品质量优于市售产品。该预处理及分离纯化工艺不仅丰富了槐糖脂类产品的品种，填补了市售产品均为内酯型和酸型槐糖脂混合物的缺陷，还可以减少有机试剂的使用量，提高槐糖脂生产的安全性与可行性，具有重要的生产指导意义，有望产生巨大经济价值。     

我国赖氨酸工业技术新进展

系统介绍了我国赖氨酸工业生产技术的发展、赖氨酸生产菌种的最新研究进展以及生产过程中的发酵、提取、浓缩、结晶、干燥等操作所采用的最新技术和设备。离子交换法是从发酵液中提取赖氨酸的常用方法 ,文中简要介绍了连续离子交换系统 (ISEP)对提高赖氨酸回收率、降低能耗和减少污水排放量的作用及其应用。     

循环冷却水中生物粘泥偏高的原因及对策

从循环冷却水系统的微生物控制、生产工艺、现场操作及设备等几个方面分析了造成循环水中生物粘泥大量超标的原因;提出了更换新型杀菌剂,加强现场管理及消除设备缺陷等相应的对策措施。对策实施后,循环水中微生物得到有效控制,异养菌等细菌大大下降,达到≤10^3个/mL,同时生物粘泥也大幅下降,达到≤3mL/m^3的指标要求。     

Effect of interphase mixing on a water–organic solvent two-liquid phase microbial system: ethanol fermentation

Ethanol fermentation by Saccharomyces cerevisiae was investigated in broth-organic solvent two-liquid phase systems with and without interphase mixing. The effect of interphase mixing with aliphatic alcohols as polar solvents and with alkanes as apolar solvents was determined from investigations in three distinct systems: a solvent-saturated broth, a solvent-broth dispersion system and a dispersion-free solvent-broth system. Microbial activities, measured as a function of solvent volume and inoculum size, revealed that a dispersed polar solvent caused a longer growth lag time and a slower growth rate. Viability measurements showed that yeast cells were gradually killed in a dodecanol-water dispersion system and not in a dispersion-free one. This process was believed to be initiated and enhanced by cell adhesion to the solvent interface as observed under a microscope. Yeast activity was also measured as a function of an apolar solvent volume and inoculum size. A full fermentative activity was observed in an initially alkanesaturated broth unlike in an intermixed biphasic system. As a result of these investigations, it was concluded firstly that microbial activity in initially solvent-saturated broths with and without contact with a stagnant solvent phase can be different and secondly that the process efficiency of a biphasic bioreactor, unlike that of a chemical reactor, can be hampered by interphase mixing. The yeast activities in the presence of the various alcohols and alkanes were correlated with ‘log P’ values of the solvents. Full activity was observed at log P > 5 and almost none at log P < 4.     

EXTRACTION OF ACETOIN FROM FERMENTATION BROTH USING AN ACETONE/PHOSPHATE AQUEOUS TWO-PHASE SYSTEM

An aqueous two-phase system (ATPS) consisting of acetone and phosphate was used to extract acetoin from fermentation broth. The influence of phase composition on partition of acetoin was investigated. When the filtered fermentation broth was used, relatively high partition coefficient (22.3) and recovery coefficient (96.4%) of acetoin were obtained by a system composed of 30% (w/w) acetone and 35% (w/w) dipotassium hydrogen phosphate. Then the system was applied to extract unfiltered fermentation broth directly, and the recovery coefficient of acetoin was 94.3%. Simultaneously, the byproduct 2,3-butanediol could also be extracted with the recovery coefficient of 93.5%. In addition, the removal of residual sucrose, cells, proteins, and prodigiosin from the fermentation broth was studied, and the removal ratios of these impurities were all above 85%. Ultimately, the recovery of phosphate in the bottom phase was explored, and the recovery coefficient could reach 93.7% through pH adjustment and dilution crystallization. The recovered phosphate also showed good ATPS extraction ability. This method provides a new possible way for the separation of acetoin from fermentation broth.     

Degradation modelling of concrete submitted to sulfuric acid attack

Bio-deterioration of concrete, which is very common in sewer system and waste water treatment plant, results in significant structure degradation. Normally, the process can be described by the two following steps: Biochemical reactions producing biogenic aggressive species (H₂SO₄ is one of the most significant biogenic acid in sewer pipes), and chemical reactions between biogenic aggressive species and cement hydration products which is responsible for concrete degradation. A reactive transport model is proposed to simulate the chemical degradation process of cementitious materials in contact with H₂SO₄ solution. The dissolution of portlandite (CH) and calcium silicate hydrates (C–S–H) and the precipitation of gypsum (p) are described by mass action law and threshold of ion activity products. To take into account the continuous decrease of the Ca/Si ratio during the dissolution of C–S–H a generalization of the mass action law is applied. A simplified damage model is introduced to characterize the degradation of concrete due to the swelling of gypsum. Some experiments reported in literature are simulated. The numerical results and the experimental observations are compared and discussed.     

青霉素发酵液膜过滤工艺研究

采用膜法处理青霉素发酵液,可以大大提高滤液质量,提高青霉素生产收率2.31%,同时可以降低后续工段的生产负荷,降低废水中的有机物含量,节能降耗,减少环保费用,有利于清洁生产.     

The possibility of the desalination of actual 1,3-propanediol fermentation broth by electrodialysis

Electrodialysis (ED) was employed to remove the organic and inorganic salts from actual 1,3-propanediol (PDO) fermentation broth. These salts cause many problems during the purification of PDO if not removed. Suitable operation parameters such as applied potential and the flow rate of streams were selected to ensure a stable and durative desalination process for PDO fermentation broth. Under these conditions, the membrane fouling can be alleviated effectively by changing pole and cleaning membranes so that further industrial production is possible. The experiment results show that about 90% of organic acid salts in PDO broth are removed by the ED process. In addition, a simulated diffusion PDO experiment proved that the diffusion of PDO results in its loss from fermentation broth and the loss ratio is less than 6% under the chosen operating conditions.     

Processing of ethanol fermentation broths by Candida krusei to separate bioethanol by pervaporation using silicone rubber‐coated silicalite membranes

BACKGROUND: Pervaporation employing ethanol‐permselective silicalite membranes as an alternative to distillation is a promising approach for refining low‐concentration bioethanol solutions. However, to make the separation process practicable, it is extremely important to avoid the problems caused by the adsorption of succinate on the membrane during the separation process. In this work, the pervaporation of an ethanol fermentation broth without succinate was investigated, as well as the influence of several fermentation broth nutrient components. RESULTS: Candida krusei IA‐1 produces an extremely low level of succinate. The decrease in permeate ethanol concentration through a silicone rubber‐coated silicalite membrane during the separation of low‐succinate C. krusei IA‐1 fermentation broth was significantly improved when compared with that obtained using Saccharomyces cerevisiae broth. By treating the fermentation broth with activated carbon, bioethanol was concentrated as efficiently as with binary mixtures of ethanol/water. The total flux was improved upto 56% of that obtained from the separation of binary mixtures, compared with 43% before the addition of activated carbon. Nutrients such as peptone, yeast extract and corn steep liquor had a negative effect on pervaporation, but this response was distinct from that caused by succinate. CONCLUSION: For consistent separation of bioethanol from C. krusei IA‐1 fermentation broth by pervaporation, it is useful to treat the low nutrient broth with activated carbon. To further improve pervaporation performance, it will be necessary to suppress the accumulation of glycerol. Copyright © 2009 Society of Chemical Industry     

Transaminase-Catalyzed Continuous Synthesis of Biogenic Aldehydes

The physiological role of biogenic aldehydes, such as 3,4-dihydroxyphenylacetaldehyde (DOPAL), has been associated with cardiovascular and neurodegenerative disorders. The availability of these substrates is limited and robust synthetic methodologies would greatly facilitate further biological studies. Herein, a transaminase-mediated single-step process in continuous mode, which leads to excellent product yields (90–95 %), is reported. Coimmobilization of the pyridoxal phosphate (PLP) cofactor eliminated the need for exogenous addition of this reagent without affecting the longevity of the system, delivering a truly self-sufficient process.     

1,3 丙二醇发酵液电渗析法脱盐

对1,3 丙二醇发酵液电渗析法脱盐的工艺进行了初步研究,主要就发酵液电导率与温度的关系、膜对电压、发酵液过滤与絮凝预处理、发酵液初始pH对脱盐效果的影响及膜的重复使用性进行了研究. 结果表明,发酵液电导率与温度呈线性关系,电导率温度校正系数为0.0217;膜对电压1.3~1.5 V为较适操作电压;脱盐过程耗时越长,1,3 丙二醇的损失越大;发酵液通过壳聚糖絮凝预处理后可以明显改善脱盐效果;发酵液pH对脱盐有明显影响,pH越低脱盐速率越快,膜连续重复使用15批次后性能下降明显,需要用NaOH和NaCl溶液进行清洗.     

离子交换在1,3-丙二醇发酵液脱盐中的应用

针对1,3-丙二醇发酵液分离提取过程中的脱盐难点问题,采用离子交换方法对1,3-丙二醇发酵液的脱盐进行了研究。选用D001强酸性阳离子交换树脂及D354弱碱性阴离子交换树脂,进行了静态、动态及连续交换工艺的实验,并对阳、阴离子交换树脂交换顺序进行了考察。结果表明,离子交换方法用于发酵液的脱盐工艺具有良好的效果,阳、阴两种离子交换树脂的交换、再生性能稳定,交换后的料液完全能够满足后续工艺的要求,为生物法1,3-丙二醇发酵液分离提取提供了一个新的工艺手段。     

苯乳酸发酵液脱色工艺及吸附方程的探讨

以脱色率及苯乳酸回收率为指标,研究了4种活性炭对发酵液吸附脱色的影响。通过单因素实验和正交实验对脱色条件进行优化,得到适宜的脱色条件为:活性炭添加质量浓度为0.015 g/L,初始pH值为6.5,温度90℃,脱色时间为30 m in,在此条件下,活性炭AC1脱色苯乳酸发酵液的脱色率为90.5%,苯乳酸回收率为88.6%。对苯乳酸发酵液脱色体系的吸附等温方程进行了研究,其吸附过程以物理吸附为主,遵循Freund lich等温方程。     

发酵液絮凝过程絮凝体微尺度与分离性能

为探索发酵液絮凝分离过程规律以提高分离效率,本文在微观层面上研究发酵液絮凝过程中的剪切力、絮凝体尺度对絮凝体过滤分离效果的影响。以小诺霉素发酵液为研究对象,在絮凝过程中改变絮凝体所受的剪切力,使用激光粒度分析仪在0.02～2000 μm尺度内测定不同剪切力下絮凝体的粒度及粒度分布,并测定絮凝体的过滤速率及沉降速率。实验结果显示：絮凝体的粒度随剪切力的增大而减小,絮凝体的粒度分布宽度随剪切力的增大而增大;絮凝体的沉降分离速率随絮凝体粒度的增大而增大;在适度的剪切力下絮凝体有一适度的粒度及粒度分布宽度和较大的密实度,此时絮凝体的过滤分离速率有一最大值。实验结果表明：絮凝过程中的剪切力显著影响絮凝体的粒度、粒度分布和密实度,从而显著影响絮凝体的过滤速率及沉降速率。