焦化废水中氰化物的处理技术研究进展

焦化废水是一种典型的难降解有毒废水,是一种世界公认难处理的工业废水。尤其是焦化废水中的氰化物,具有含量高、毒性大的特点,随意排放会污染水源和农田,造成鱼类的死亡和农作物的减产。因此如何高效价廉地去除焦化废水中的氰化物成为一个值得研究的问题。本文概述了国内外各种去除焦化废水中氰化物的处理方法和应用,主要分为生物法和物理化学法两大类。生物法利用微生物对废水中的污染物进行降解,但是单独使用生物法无法达到排放标准,所以要结合其他方法进行联合处理;简述了碱性氯化法、氰化铁沉淀法、Fenton工艺、活性炭吸附法、臭氧法、离子交换法、二氧化硫与空气法、膜生物反应器（MBR）和膜处理法等物理化学方法各自的优缺点,并提出了今后的发展方向;以期达到高效低耗处理焦化废水中氰化物的目的。     

Online monitoring of a bioprocess based on a multi‐analyser system and multivariate statistical process modelling

Multivariate statistical process control (MSPC) was for the first time applied to analyse data from a bioprocess on‐line multi‐analyser system consisting of an electronic nose (EN), a near‐infrared spectroscope (NIRS), a mass spectrometer (MS) and standard bioreactor probes. One hundred and fifty sensor signals from the electronic nose, 1050 wavelength signals from the NIRS, carbon dioxide evolution rate calculated from mass spectrometer signals and standard bioreactor data (eg amount of substrate fed) were interrogated for their ability to model a bioprocess using MSPC. The models obtained were validated on a recombinant Escherichia coli fed‐batch process for tryptophan production. Limiting trajectories were defined in the MSPC models for warning, action, and process experience with respect to biomass and tryptophan concentrations. The results showed the capacity and robustness of MSPC models for monitoring with multi‐analysers and allowed a comparison of the different analysers' suitability for this kind of data processing. Furthermore, the results demonstrate that MSPC models provide a functional and versatile framework for coping with large information flows and are also suited to a variety of other bioprocessing monitoring and control tasks. © 2002 Society of Chemical Industry     

A systems engineering perspective on process integration in industrial biotechnology

Biotechnology has many applications in health care, agriculture, industry and the environment. By using renewable raw materials, biotechnology contributes to lowering greenhouse gas emissions and moving away from a petro‐based towards a circular sustainable economy. However, major developments are still needed to make industrial biotechnology an economic alternative to conventional processes for fuels, specialty and/or bulk chemicals production. Process integration is a holistic approach to process design, which emphasizes the unity of the process and considers the interactions between different unit operations from the outset, rather than optimizing them separately. Furthermore, it also involves the substitution of two or more unit operations by one single novel unit capable of achieving the same process goal. Conversely, process systems engineering (PSE) deals with the analysis, design, optimization, operation and control of complex process systems, as well as the development of model‐based methods and tools that allow the systematic development of processes and products across a wide range of systems involving physical and chemical change. Mature tools and applications are available for chemical technology and steps have been taken to apply PSE principles also to bioprocess technology. This perspective paper argues that an interdisciplinary approach is needed towards integrated bio‐processing in order to link basic developments in biosciences with possible industrial applications. PSE can foster the application of existing and the development of new methods and tools for bioprocess integration that could promote the sustainable production of bio‐/chemical products. The inclusion of PSE principles and methods in biochemical engineering curricula and research is essential to achieve such goals. © 2014 Society of Chemical Industry     

生物法制造丁二酸研究进展

丁二酸因其C₄分子结构在化工领域的潜在价值,被认为是一种具有广阔应用前景的生物基平台化合物。结合生物基丁二酸的产业现状,综合分析了丁二酸生产菌种及菌株改造、生物过程优化和丁二酸分离纯化这三个方面的研究现状。重点介绍以大肠杆菌、产琥珀酸放线杆菌、解脂耶氏酵母为代表的主要生产菌株及其改造策略;低值生物质利用及控制发酵过程中CO₂供给和pH调节等生物过程优化策略;包括钙盐法、电渗析法、直接分离法等方法在内的丁二酸分离工艺。同时指出未来的研究重点将综合考虑经济性与能耗问题,将菌株与发酵和分离全过程整合,提高丁二酸产量,降低发酵及分离成本,进一步拓展生物基丁二酸市场应用领域。     

外电阻值对3A-MFC产电和脱氮性能的影响

构建三阳极单阴极型微生物燃料电池（three-anode microbial fuel cells,3A-MFC）,该间歇流反应器通过在阳极提供有机物,在阴极提供有机物、氨氮和氧气,在产电的同时实现生物阴极同步硝化反硝化脱氮。考察了外电阻值分别为1000Ω、500Ω、150Ω、50Ω时对3A-MFC产电及脱氮性能的影响,当外电阻值为150Ω时,产电量达到最大值为583C,阳极库仑效率达到最大值为1.70%,内阻达到最小值为200Ω,此时外电阻值与内阻值最接近,产电效果最好。外电阻值由1000Ω减小到150Ω时,总氮（TN）去除率从79.7%上升到最大值为84.1%,TN去除速率从7.5mg/(L·d)上升到最大值为13.1mg/(L?d)。在一定外电阻值范围内,伴随其值的减小,电子转移速率逐渐提高,同时电对微生物的刺激作用得到增强,能够实现最佳的TN去除效率和去除速率。     

Development of a hybrid neural network model to predict feeding method in fed‐batch cultivation for enhanced recombinant streptokinase productivity in Escherichia coli

BACKGROUND: A simple and efficient model for enhancing production of recombinant proteins is essential for cost effective development of processes at industrial scale. A hybrid neural network (HNN) model is proposed combining an unstructured model and neural network to predict the feeding method for the post‐induction phase of fed‐batch cultivation for increased recombinant streptokinase activity in Escherichia coli. RESULTS: The parameters of the unstructured model were estimated from experiments conducted with various feeding methods. The simulated model described the dynamics of the process satisfactorily, however, its predictive capability of the process for different feeding methods is limited due to wide disparity in process parameters. In contrast, a neural network model trained to map the variations in process parameters to state variables complements the ‘first principle’ model in predicting the state variables effectively. CONCLUSIONS: The HNN model is able to predict the product profile for different substrate feed rates. Further, the average volumetric streptokinase activity predicted by the HNN model matches closely the experimental values for fed‐batches having high as well as low streptokinase activity. The HNN model developed in this study could facilitate development of a process for recombinant protein production with minimum number of experiments. Copyright © 2011 Society of Chemical Industry     

Media photo‐degradation in pharmaceutical biotechnology – impact of ambient light on media quality,cell physiology,and IgG production in CHO cultures

BACKGROUND

Many vital components in bioprocess media are prone to photo‐conversion or photo‐degradation upon exposure to ambient light, with severe negative consequences for biomass yield and overall productivity. However, there is only limited awareness of light irradiation as a potential risk factor when working in transparent glass bioreactors, storage vessels or disposable bag systems. The chemical complexity of most media renders a root‐cause analysis difficult. This study investigated in a novel, holistic approach how light‐induced changes in media composition relate to alterations in radical burden, cell physiology, morphology, and product formation in industrial Chinese hamster ovary (CHO) bioprocesses.

RESULTS

Two media formulations from proprietary and commercial sources were tested in a pre‐hoc light exposure scenario prior to cultivation. Using fluorescence excitation/emission (EEM) matrix spectroscopy, a photo‐sensitization of riboflavin was identified as a likely cause for drastically decreased IgG titers (up to ?80%) and specific growth rates (?50% to ?90%). Up to three‐fold higher radical levels were observed in photo‐degraded medium. On the biological side, this resulted in significant changes in cell morphology and aberrations in the normal IgG biosynthesis/secretion pathway.

CONCLUSION

These findings clearly illustrate the underrated impact of room light after only short periods of exposure, occurring accidentally or knowingly during bioprocess development and scale‐ up. The detrimental effects, which may share a common mechanistic cause at the molecular level, correlate well with changes in spectroscopic properties. This offers new perspectives for online monitoring concepts, and improved detectability of such effects in future. © 2018 The Authors. Journal of Chemical Technology & Biotechnology published by JohnWiley & Sons Ltd on behalf of Society of Chemical Industry.

     

生物法拆分外消旋甲霜灵制备R-甲霜灵

从土壤和污泥样品中分离得到一株能不对称水解甲霜灵的革兰阴性菌。通过分子生物学鉴定,命名该菌株为Albibacters sp.zjut528。当底物浓度为50 g·L^-1,湿菌体（含水量81%）：底物=0.3：1（质量比）,反应28 h,产物得率为47.1%,主产物为R-甲霜灵酸,对映体过量值ee_p > 99.9%。将菌株细胞破碎得到的粗酶液分离纯化得到一个SDS-PAGE电泳纯的酯酶,分子量约为40×10³,酶的N端10个氨基酸序列为NH₂-Ala-Ala-Lys-Ala-Pro-Leu-Arg-Leu-Lys-Glu。该酶最适温度为40℃,20~40℃稳定性较好。最适pH为9.0,在pH 5.0~10.0范围内稳定。Fe²⁺、Mn²⁺、Zn²⁺对酶活有促进作用,Fe³⁺对酶活有一定的抑制作用。在含有20%的乙腈、异丙醇、丙酮、二异丙醚、环己烷、正己烷的水溶液中,酶活均比在纯水相中有明显提高。该酶反应动力学符合米氏方程,V_m为0.18 mmol·L^-1·min^-1,K_m为2.29 mmol·L^-1,K_cat为0.85 min^-1。建立了一条利用Albibacters sp.zjut528细胞作催化剂拆分甲霜灵制备R-甲霜灵的工艺路线,终产品R-甲霜灵的纯度是96.2%,ee值为99.3%。     

Flowsheet simulation of aqueous two‐phase extraction systems for protein purification

BACKGROUND: Aqueous two‐phase extraction (ATPE) has many advantages as an efficient, inexpensive large‐scale liquid–liquid extraction technique for protein separation. However, the realization of ATPE as a protein separation technology at industrial scales is rather limited due to the large, multidimensional design space and the paucity of design approaches to predict phase and product behavior in an integrated fashion with overall system performance. This paper describes a framework designed to calculate suitable flowsheets for the extraction of a target protein from a complex protein feed using ATPE. The framework incorporated a routine to set up flowsheets according to target protein partitioning behavior in specific ATPE systems and a calculation of the amounts of phase‐forming components needed to extract the target protein. The thermodynamics of phase formation and partitioning were modeled using Flory‐Huggins theory and calculated using a Gibbs energy difference minimization approach. RESULTS: As a case study, suitable flowsheets to recover phosphofructokinase from a simple model feedstock using poly(ethylene glycol)‐dextran (PEG6000‐DxT500) and poly(ethylene glycol)‐salt (PEG6000‐Na₃PO₄) two‐phase systems were designed and the existence of feasible solutions was demonstrated. The flowsheets were compared in terms of product yield, product purity, phase settling rate and scaled process cost. The effect of the mass flowrates of phase‐forming components on product yield and purity was also determined. CONCLUSION: This framework is proposed as a basis for flowsheet optimization for protein purification using ATPE systems. Copyright © 2010 Society of Chemical Industry     

From process experts to a real-time knowledge-based system

This paper describes the development and implementation of a real-time knowledge-based system (RTKBS) carried out in collaboration with Eli Lilly in the UK. The RTKBS was developed in order to provide consistent advice to the operators of a large-scale antibiotic production plant in real time. The ultimate objective was to reduce variability and improve the process yield. A wealth of process information exists in the experience of the process operators, engineers and scientists, and it was capitalized upon in this application. However, this information tends primarily to be qualitative in nature and its elicitation traditionally represents a bottleneck in developing an RTKBS. The paper demonstrates that this type of process knowledge can be effectively and rapidly captured and then coded within an RTKBS. The project was undertaken in two stages. During the knowledge elicitation stage the specific application area was identified in consultation with the industrial partner and qualitative knowledge in the selected area was extracted from experts/operators using KAT™ (a structured technique for knowledge elicitation). Subsequently this knowledge was converted into a rule base and implemented within G2, which then acted as an advisory/decision support system.