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February 28th, 2010 at 7:16 am

Biocatalyst introduction


Over the past 20 years, many reservations have been expressed with respect to catalysis, arguing that: (i) enzymes only feature limited substrate specificity, (ii) there is only limited availability of enzymes, (iii) only a limited number of enzymes are enzymes; yield (iv) the stability of catalytic proteins is limited, (v) enzymatic reactions have limited space-time, and (vi) require complicated cosubstrates as cofactors.

Following the discovery of many new enzymes by recombinant DNA technology, which allows both the production more efficient and focused combinatorial or alteration of individual enzymes, and the process of development towards greater stability and volumetric productivity, routes of synthesis in which one or all of the steps are biocatalytic have advanced dramatically in recent years. Design rules for improving biocatalysts are increasingly precise and easy to use.

Biocatalysts are not operating from different scientific principles from organic catalysts. The existence of a multitude of patterns of enzymes as catalysts oligopeptidic or polypeptide shows that the entire action of enzymes can be explained by rational chemical and physical principles. However, enzymes can create unusual reaction conditions and higher pKa values as low or a high positive potential for a redox metal ion. Enzymes were always found in almost all catalyze reactions in organic chemistry.

Biotechnology and biocatalysis differ from conventional processes, not only with a different type of catalyst, they also constitute a basis of new technologies. The basic raw material of a biological process is built based on sugar, lignin, animal or plant waste in the field of biotechnology, such as unit operations membrane processes, chromatography, biocatalysis or predominate, and the range of products biotechnological processes often includes chiral molecules or biopolymers such as proteins, nucleic acids or carbohydrates.

Cost and margin pressure from competitors less expensive and cooperation with emphasis on a clean surface (or less polluted), the environment are two important developments. Less preparation, with higher yields at every step, lower costs of materials and energy, and less waste targets. Biotechnology and biocatalysis often offer options unique technology and solutions, they act as enabling technologies, in other cases, biocatalysis is to outperform competing technologies to gain access. In the field of pharmaceutical drugs, the reason this unit for the enantiomeric purity is that the vast majority of new drug targets are chiral biocatalysis as promoting the technology with the best performance of selectivity.

Biocatalytic processes to penetrate more and more the chemical industry. In a recent study, 134 industrial-scale biotransformations, on a scale of> 100 kg with whole cells or enzymes from a precursor other than a C-source, were analyzed. Hydrolase (44%), followed by oxido-reductase (30%), dominate the industrial biocatalytic applications. Data on the average performance of fine chemicals (non-pharmaceutical) applications were made 78%, a concentration of 108 g of the final product of L and a volumetric productivity of 372 g (L • D)

Applications of Biocatalysis in Industry

Chemical Industry of the Future: Manufacturing environmentally benign, green chemistry, sustainable development in the future

Because of two very strong and important driving forces of the chemical industry of the future will be very different from today’s version:

* Cost and margin pressure of competition in an increasingly open market-oriented economy, and
* Operation of the sector in a social framework that places emphasis on a clean (or cleaner) environment

Treatment with the intent of this new set of conditions focuses on the development of production chains with fewer stages of processing, with higher yields at every step, to save material and energy costs. Less waste is generated, and the treatment and disposal fall. Both the pressures encountered in the case of environmental compliance costs.

In many cases, such as the high-fructose corn syrup, or biotechnology and biocatalysis technologies offer options and solutions that are not available through any other technology, in such situations, such as acrylamide, nicotinamide or intermediates for antibiotics , biotechnology and biocatalysis act as “enabling technologies”. In the remaining situations, biotechnology and biocatalysis offer a solution among others, who all must be evaluated according to criteria developed in Chapter 2: product yield, selectivity, productivity, (bio) catalyst stability, and space-time-performance .

In this context, the three terms in the title are largely synonymous, however, that have been developed in a slightly different context:

* Production is a movement toward environmentally-friendly production systems that are both economically and environmentally sound manner;
* Sustainable development is a worldwide movement and the chemical industry represents a set of guidelines on how to manage resources so that no sources are minimized as much as possible;
* Green Chemistry is the design of chemical products and processes to reduce or eliminate the use and production of hazardous substances.

“Green Chemistry is a comprehensive approach that applies to all aspects of chemistry” (Anastas, 2002). Methods of green chemistry can be viewed through the framework of the “Twelve Principles of Green Chemistry (Anastas, 1998):

1. It ‘better to prevent waste than to treat or clean up waste after it is formed.
2. Synthetic methods should be designed to maximize the integration of all
3. materials used in the production process of the final product. As far as practicable, synthetic methodologies should be designed to use and generate substances that possess little or no toxicity to human health and the environment.
4. The chemicals must be designed to preserve the effectiveness of the function by reducing the toxicity.
5. The use of auxiliary substances (eg solvents, separation agents, etc.) should be made unnecessary wherever possible and should be harmless if used.
6. Energy requirements should be recognized for their environmental and economic impacts and should be minimized. Synthetic methods should be conducted at ambient temperatures and pressures.
7. A raw material or feedstock should be renewable rather than depleting wherever technically and economically feasible.
8. Unnecessary derivatization (blocking group, protection / deprotection, temporary modification of physical / chemical processes) should be avoided wherever possible.
9. Catalytic reagents (as selective as possible) are superior to stoichiometric reagents.
10. The chemicals must be designed so that at the end of their function will not persist in the environment and break down into innocuous degradation products.
11. Analytical methods must be further developed to allow real-time, in a process of monitoring and control prior to the formation of hazardous substances.
12. Substances and the form of a substance used in a chemical process should be chosen so as to minimize the risk of chemical accidents, including releases, explosions and fires.

Catalysis offers numerous advantages for the achievement of green chemistry: novel, high-efficiency, shortest paths process, greater selectivity and low temperatures and pressures. Biocatalysis combines the goals of all three issues mentioned above. Biocatalysts, as well as many raw materials, especially to heat, in turn, are completely renewable and for the most part, do not pose any harm to humans or animals. By reducing temperatures and high pressures and large consumption of metals and organic solvents, waste production per unit of product is drastically reduced.

Biocatalysis. Andreas S. Bommarius and Bettina R. Riebel
Copyright © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim ISBN: 3-527-30344-8

Tags: Action Of Enzymes, Biocatalysts, Biological Process, Biotechnological Processes, Chiral Molecules, Cofactors, Conventional Processes, Enzymatic Reactions, Enzymes As Catalysts, Margin Pressure, Membrane Processes, Metal Ion, Nucleic Acids, Organic Catalysts, Organic Chemistry, Physical Principles, Pka Values, Recombinant Dna Technology, Substrate Specificity, Unit Operations


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