生物催化与生物转化腈类化合物生产化工原料及医药中间体

生物催化进入传统的化工领域给原料来源、能源消耗、经济效益、环境保护等方面带来了根本性的变化。作为生物技术第三次浪潮标志的生物催化技术已成为发达国家的重要科技与产业发展战略，各国都加大了生物催化的研发力度，以生物催化技术为核心的生物制造产业正以指数规律加速发展。目前，美国在酶催化剂及手性化合物合成方面已处于领先地位，其生物催化制造的化学品产值已超过生物医药的产值．美国提出，新的生物催化剂是21世纪可持续发展的化学加工业的必需工具。到2020年通过生物催化技术，化学加工业的原料、水资源及能量消耗将各降低30％，减少污染物排放和污染扩散30％。我国医药生物技术与发达国家相比差距较大，不具备竞争优势。但我国在生物催化领域起步与发达国家相差不多，真正能够参与国际竞争之处正在于此。随着生物催化和生物转化技术的发展，我国的工业生物技术也可能实现跨越式发展。增大生物催化与生物转化技术的贡献率。     

生物催化与生物转化腈类化合物生产化工原料及医药中间体

1 前言 生物催化进入传统的化工领域给原料来源、能源消耗、经济效益、环境保护等方面带来了根本性的变化。作为生物技术第三次浪潮标志的生物催化技术已成为发达国家的重要科技与产业发展战略，各国都加大了生物催化的研发力度，以生物催化技术为核心的生物制造产业正以指数规律加速发展。目前，美国在酶催化剂及手性化合物合成方面已处于领先地位，其生物催化制造的化学品产值已超过生物医药的产值．美国提出，新的生物催化剂是21世纪可持续发展的化学加工业的必需工具。到2020年通过生物催化技术，化学加工业的原料、水资源及能量消耗将各降低30％，减少污染物排放和污染扩散30％。我国医药生物技术与发达国家相比差距较大，不具备竞争优势。但我国在生物催化领域起步与发达国家相差不多，真正能够参与国际竞争之处正在于此。随着生物催化和生物转化技术的发展，我国的工业生物技术也可能实现跨越式发展。增大生物催化与生物转化技术的贡献率。     

生物催化：可持续发展的希望——访南京工业大学校长、中国工程院院士欧阳平凯

生物催化与生物转化的核心目标,是在化工领域大规模采用微生物或酶为催化剂,大规模生产有机化学品。     

镁基固体催化剂催化酯交换反应制备生物柴油研究进展

生物柴油是一种重要的可再生能源,非均相催化甘油酯酯交换反应制备生物柴油是当前的研究热点,而高活性的非均相催化剂则是非均相催化工艺的核心。镁基催化剂由于其原料来源广泛、价格低廉,受到了广泛关注。综述近年来镁基催化剂催化酯交换反应制备生物柴油的研究进展,重点介绍了镁基催化剂制备方法、组成、结构、反应条件等对催化酯交换反应活性的影响,并探讨了镁基催化剂目前存在的不足以及今后的发展方向。     

极端微生物与工业生物催化剂开发

工业催化领域对生物催化剂提出了苛刻的要求,特别是高浓度底物或产物、高离子强度、酸碱条件及其非水相催化,如何获得高效的生物催化剂是催化技术发展的关键。极端微生物是高效工业生物催化剂的重要来源,本文主要介绍从嗜热菌、嗜盐菌或耐盐菌、耐辐射微生物、耐有机溶剂等极端微生物出发发现并开发高效工业生物催化剂,可望为生物技术的进一步发展提供一个更广阔的资源。     

催化酯交换制备生物柴油的研究进展

催化酯交换是制备生物柴油的一个重要方法。本文综述了均相催化和非均相催化、酸性催化和碱性催化、固体酸和固体碱催化的研究进展,并针对每类催化剂的特性和应用范围进行比较,得出固体酸和固体碱催化符合绿色生产生物柴油的要求,是未来发展的方向。特别是固体酸在催化含有水分和游离酸的油脂酯交换方面具有独特的优势,需要进一步研究和开发。     

酯化及转酯化法制备生物柴油过程中催化剂的研究进展

酯化及转酯化法是目前研究最多、最具优势的生物柴油制备方法,根据原料特性选择合适的催化刺是该法成功的重要保证.在简述生物柴油制备原理的基础上,重点综述了目前研究较多的各种酸催化剂、碱催化剂、脂肪酶催化剂、离子液体及无催化剂过程的优缺点,并对生物柴油催化剂的发展方向进行了展望.     

催化进展概述(二) 第三部分 生物催化

生物工程正以令人注目的姿态进入世界的科技、工业舞台,生物催化是其中的一个重要分支。生物催化剂是原料经生物转化为产品的生化过程中所必须的媒介,它的定义与一般用于有机或无机催化反应中的催化剂     

生物催化及其在手性技术中的应用

综述了生物催化主要研究方向,包括筛选新型生物催化剂、建立高通量的筛选技术平台、改造催化剂、开发新的生物催化反应类型及介质工程研究等,同时介绍了生物催化在手性技术中的应用,指出了生物催化技术存在的问题并展望未来的发展方向。     

组合催化的原理、策略与发展

介绍了组合催化的基本原理和催化剂库的高通量筛选方法;讨论了组合催化技术的2个关键因素———催化剂库的合成方法和相应的高通量检测技术在催化研究中的重要作用。综述了组合催化技术在无机、有机以及生物催化领域中的应用进展,指出进一步与计算机相结合,研究新的催化剂体系、开发新的催化剂合成技术和新的筛选技术是今后组合催化的发展方向和趋势。     

工业生物技术的研究现状与发展趋势

工业生物技术是以微生物或酶为催化剂进行物质转化,大规模生产人类所需的化学品、医药、能源、材料等,是解决人类目前面临的资源、能源及环境危机的有效手段.世界经合组织指出：“工业生物技术是工业可持续发展最有希望的技术”.本文指出工业生物技术的新崛起,并已成为发达国家的重要科技与产业发展战略.概述了工业生物技术的发展现状与趋势,特别在生物能源、生物材料以及生物质资源化方面.介绍了工业生物技术的关键问题是：（1）微生物资源库和微生物功能基因组学技术;（2）生物催化剂快速定向改造新技术;（3）重要工业微生物的代谢工程.展望了我国工业生物技术发展前景.     

Reaction Engineering for the Industrial Implementation of Biocatalysis

Biocatalytic processes (using one or more enzymes) for the production of chemicals is an important potential route to more sustainable manufacturing and today have found application in several industries, but most notably in the pharmaceutical sector. For high-priced pharmaceuticals, the development of new processes is primarily dependent upon enzyme development. However, the wider application of biocatalytic processes towards lower-priced chemicals will demand reaction engineering to be considered, alongside biocatalyst development. Bioreaction engineering should include an evaluation of the thermodynamics and reaction kinetics, as well as the stability of the biocatalyst. In this brief article, tools to assist in the collection and evaluation of reaction engineering data will be discussed, and illustrated using biological oxidation as an example.

     

Processing efficiency of immobilized non-growing bacteria: Biocatalytic modeling and experimental analysis

Modeling methods used to optimize the biocatalytic efficiency of freely suspended cells have been applied to non-growing microbial cells entrapped within a macro-porous carrier. The catalytic rate, which is dependent on cell concentration inside the biocatalyst beads, coincided with catalytic parameters for freely suspended cells. Immobilized non-growing cell systems could be optimized utilizing the characteristics of freely suspended cells without requiring extensive experimentation to define catalytic behaviour inside the biocatalyst. A dynamic diffusion–reaction model was developed and validated using experimental data for thiodiglycol degradation by Alcaligenes xylosoxidans subsp. xylosoxidans immobilized within macro-porous poly(vinyl alcohol) cryogel in a completely mixed batch bioreactor.     

A future perspective on the role of industrial biotechnology for chemicals production

The development of recombinant DNA technology, the need for renewable raw materials and a green, sustainable profile for future chemical processes have been major drivers in the implementation of industrial biotechnology. The use of industrial biotechnology for the production of chemicals is well established in the pharmaceutical industry but is moving down the value chain toward bulk chemicals. Chemical engineers will have an essential role in the development of new processes where the need is for new design methods for effective implementation, just as much as new technology. Most interesting is that the design of these processes relies on an integrated approach of biocatalyst and process engineering.     

生物催化剂固定化技术的研究进展

综述了近年来在生物催化剂固定化技术研究中的一些最新方法，在此基础上提出了新的用于评价固定化技术优劣性的标准，并对所阐述各种固定化方法进行了比较，为研究和发展出更有效。更具有普适性的生物催化剂固定化技术提供必要的参考。     

Promiscuous enzyme‐catalyzed Michael addition: synthesis of warfarin and derivatives

BACKGROUND: Biocatalytic promiscuity has attracted much attention from chemists and biochemists in recent years. Warfarin, one of the most effective anticoagulants, has been introduced for clinical use as a racemate for more than half a century. Although some different chemical strategies towards the synthesis of optically active warfarin have been reported, biocatalytic preparation of warfarin remains unexploited. RESULTS: Lipase from porcine pancreas (PPL) was used as a biocatalyst to catalyze the Michael addition of 4‐hydroxycoumarin to α,β‐unsaturated enones in organic medium in the presence of water to synthesize warfarin and derivatives. The products were obtained in moderate to high yields (up to 95%) with none or low enantioselectivities (up to 28% ee). The influence of reaction conditions including solvents, temperature and molar ratio of substrates was systematically investigated. CONCLUSION: Among the many reported lipase‐catalyzed Michael additions, only a few showed enantioselectivity. Therefore, this Michael addition activity of, for example, PPL is a valuable case of enantioselective lipase catalytic promiscuity. In addition, it was the first time warfarin and derivatives were prepared using a biocatalyst. Copyright © 2012 Society of Chemical Industry     

IsPETase Is a Novel Biocatalyst for Poly(ethylene terephthalate) (PET) Hydrolysis

Poly(ethylene terephthalate) (PET) is one of the most widely used synthetic polyesters, but also a major cause of plastic pollution. Because the chemical degradation of PET would be uneconomical and rather burdensome, considerable efforts have been devoted to exploring enzymatic processes for the disposal of PET waste. Many PET-hydrolyzing enzymes have been reported in recent decades, some of which demonstrate excellent potential for industrial applications. This review sets out to summarize the state of investigation into IsPETase, a cutinase-like enzyme from Ideonella sakaiensis possessing ability to degrade crystalline PET, and to gain further insight into the structure–function relationship of IsPETase. Benefiting from the continuing identification of novel cutinase-like proteins and growing availability of the engineered IsPETase, we may anticipate future developments in this type of enzyme would generate suitable biocatalyst for industrial use.     

Carica papaya latex: A low‐cost biocatalyst for human milk fat substitutes production

This work aims at evaluating the potential of Carica papaya lipase (CPL) self‐immobilized in papaya latex as a biocatalyst for the synthesis of human milk fat substitutes (HMFS), to be used as a low‐cost alternative to commercial lipases. Two different CPL preparations, one extracted from the papaya fruit (CPL I) and the other from petiole leaves (CPL II) of papaya tree, were tested as catalysts for the acidolysis between tripalmitin and (i) oleic acid or (ii) omega‐3 PUFA, batchwise, at 60°C, in solvent‐free media. After 24 h, molar incorporation was higher for oleic acid (22.1 mol%) when CPL I was used. This biocatalyst was selected for further studies. RSM was used to model reaction conditions: medium formulation (molar ratio oleic acid/tripalmitin, MR, 1.2:1–6.8:1) and temperature (58–72°C). Acyl migration decreased with MR increase. In batch operational stability assays at 60°C, using MR of 2:1 and 6:1, the highest stability was observed for a MR of 2:1. Practical applications: The use of this biocatalyst is a feasible way to valorize papaya agro‐residues which represent an important environmental problem in the producing countries. The obtained results were rather promising since, with this almost zero‐cost biocatalyst, it was possible to produce a high added‐value product (HMFS). Under optimized conditions, the obtained results were comparable with those obtained with expensive immobilized commercial lipases.     

Oxidase-Peroxidase sequential polymerization for removal of a dye from contaminated water by horseradish peroxidase (HRP)/glucose oxidase (GOx)/polyurethane hybrid catalyst

Horseradish peroxidase (HRP) and glucose oxidase (GOx) were co-immobilized on polyurethane, and the resulting HRP/GOx/polyurethane biocatalyst was characterized using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDAX) mapping techniques. The prepared biocatalyst was used for removal of acid orange 7 as model azo dye. The required H₂O₂ for activation of HRP was in-situ produced using GOx to prevent deactivation of HRP in the presence of excess chemical H₂O₂. Central composite design (CCD) was applied for modeling and optimization of parameters affecting the activity of prepared biocatalyst. Under the optimum conditions, removal efficiency of the azo dye was predicted to be 87.47%, which was in good agreement with the experimental value (89.69%). In addition, the performance of the prepared biocatalyst for removal of two other dyes with different structure was investigated at the optimum conditions, and a removal efficiency of 91.56% and 95.25% was obtained for removal of methylene blue and malachite green, respectively. The results demonstrated that the resultant HRP/GOx/Polyurethane biocatalyst was able to decrease the chemical oxygen demand (COD) of a textile effluent from 740mg/L to 96mg/L, indicating that the prepared biocatalyst is an effective enzymatic system for treatment of real wastewater.     

Sulfur specificity in the bench‐scale biological desulfurization of crude oil by Rhodococcus IGTS8

Biological removal of organic sulfur from petroleum feedstocks may offer an attractive alternative to conventional thermochemical treatment due to the mild operating conditions and greater reaction specificity afforded by the nature of biocatalysis. Previous investigations have either reported the desulfurization of model sulfur compounds in organic solvents or gross desulfurization of crude oil without data on which sulfur species were being removed. This study reports initial sulfur speciation data for thiophenic sulfur compounds present in crude oil which may be used as a guide both as to which species are treated by the biocatalyst investigated as well as to where biocatalyst development is needed to improve the extent of biological desulfurization when applied to whole crudes. Biodesulfurization of two different crude oils in the 22–31 ° API specific gravity range with total sulfur contents between 1 and 2% is demonstrated in 1‐dm³ batch stirred reactors using wild type Rhodococcus sp IGTS8. While analysis of the crudes before and after biodesulfurization did not reveal a decrease in total sulfur, GC–MS did reveal significant (43–99%) desulfurization of dibenzothiophenes (DBT) and substituted DBTs. Fractionation of the whole crude, followed by analysis using gas chromatography–sulfur chemiluminescence detection (GC–SCD) of the aromatic fraction of the Van Texas crude oil, demonstrated a reduction of sulfur in this fraction from 3.8% to 3.2%. This research indicates that IGTS8 may be capable of biodesulfurization of refined products such as gasoline and diesel whose predominant sulfur species are dibenzothiophenes. Further biocatalyst development would be needed for effective treatment of the spectrum of sulfur‐bearing compounds present in whole crudes.