Biotechnological solutions

Chmielewski AG, Harasimowicz M, Zakrzewska-Trznadel G. In Howell JA, Noworyta A, eds. Towards Hybrid Membrane and Biotechnology Solutions for Polish Environmental Problems. Wroclaw, Poland Wroclaw Technical University Press, 1995. 

As the chemical industry turns more and more to biotechnological solutions for chemical and fuel production, the end goal is an optimization of the process to meet given economic criteria. Thus, extreme thermophiles must find then-niche on the basis of their intrinsic properties as hosts. While there are currently no known industrial products produced through the use of metabolically engineered extreme thermophiles, the attributes of these organisms make them excellent prospects for further development for future industrial use. 

Biopolymer Extraction. Research interests involving new techniques for separation of biochemicals from fermentation broth and cell culture media have increased as biotechnology has grown. Most separation methods are limited to small-scale appHcations but recendy solvent extraction has been studied as a potential technique for continuous and large-scale production and the use of two-phase aqueous systems has received increasing attention (259). A range of enzymes have favorable partition properties in a system based on a PGE—dextran—salt solution (97) ... 

Biomedical and Biotechnology. The use of mictocapsules for a variety of biomedical and biological appHcations has been promoted for many years (50,51). Several biomedical mictocapsule appHcations ate in clinical use or have approached clinical use. One appHcation is the use of air-fiUed human albumin mictocapsules as ultrasound contrast agents. Such mictocapsules, caUed mictobubbles, ate formed by ultrasonicating 5% albumin solutions to produce 4—10-)J.m diameter air-fiUed capsules (52). When injected the capsules act as a useful transpulmonary echo contrast agent (53) that has been approved for use in humans by the U.S. FDA. 

Crossflow Filters - These are usually membrane-type filters used for ultrafiltration. In the field of biotechnology these types of filters are used in ultrafiltration devices used in concentrating solutions, and performing buffer exchanges. 

Cake Filters - These are filters that are used to remove large amounts of solids from a slurry solution. They would normally be seen in biotechnology in the primary clarification of fermentation batches and in a variety of solids removal steps seen in the production of drugs via organic synthesis. 

The first two categories, clarifying and crossflow filters, have been very well developed and optimized for use in biotechnology and standard wastewater treatment applications. Equipment is easily available for these applications, whether as small 0.2 micron sterilizing filter used to terminally sterilize 100 ml of product solution, or a small 500 ml crossflow filter used to concentrate a small amount of antibody solution. Many vendors of this equipment to wastewater treatment applications have their origins in the CPI (Chemical Process Industries), and have incorporated many of the scale-up and optimization properties developed in much larger units used in large scale chemical production. As a result, these two filtration unit operations are one of the most optimized and efficient used in wastewater treatment. 

Although it is possible to obtain cells from whole animals or plants and to cultivate them in suitable nutrient solutions, in general they are not as easy to handle as microbes. Nevertheless, plant and animal cells are a valuable genetic resource for biotechnology and many newly developed bioprocesses rely on transfer of their genes to micro-organisms. 

The commercialization of developments in biotechnology will require a new breed of chemical engineer, one with a solid foundation in the life sciences as well as in process engineering principles. This engineer will be able to bring iimovative and economic solutions to problems in health care delivery and in the large-scale implementation of advances in molecular biology. 

As a result of the micellar environment, enzymes and proteins acquire novel conformational and/or dynamic properties, which has led to an interesting research perspective from both the biophysical and the biotechnological points of view [173-175], From the comparison of some properties of catalase and horseradish peroxidase solubilized in wa-ter/AOT/n-heptane microemulsions with those in an aqueous solution of AOT it was ascertained that the secondary structure of catalase significantly changes in the presence of an aqueous micellar solution of AOT, whereas in AOT/n-heptane reverse micelles it does not change. On the other hand, AOT has no effect on horseradish peroxidase in aqueous solution, whereas slight changes in the secondary structure of horseradish peroxidase in AOT/n-heptane reverse micelles occur [176],... 

The BiodeNOx process is a novel process concept to reduce NO emissions from flue gases of stationary sources like power plants and other industrial activities [1]. The concept combines a wet chemicd absorption process with a novel biotechnological regeneration method. In the wet chemical absorption step, flue gas components are absorbed into an aqueous solution of Fe"(EDTA) (EDTA= ethylme-diamino-tetraacetic acid). The following reactions take place ... 

Surfactant Solutions New Methods of Investigation, edited by Raoul Zana Nonionic Surfactants Physical Chemistry, edited by Martin J. Schick Microemulsion Systems, edited by Henri L Rosano and Marc Clausse Biosurfactants and Biotechnology, edited by Naim Kosaric, W. L. Cairns, and Neil C. C. Gray... 

Petsch, D. and Anspach, F.B. (2000) Endotoxin removal from protein solutions. Journal of Biotechnology, 76 (2-3), 97-119. 

Nevertheless, there are several hurdles to overcome. Biotransformation has to compete with a chemical production process. The production of bio-based bulk chemicals and intermediates from white biotechnology must be economically viabile [67]. This means that the biotechnological product must be cheaper to produce or of higher quality than products based on classical chemical routes. And, incidentally, switching to a novel process takes time and money. Therefore, process solutions are required which are adapted to the special needs of biocatalyzed reactions. Within this chapter, several specific tasks have been addressed, illustrating universal possibilities to overcome the limitations found in bioprocesses. 

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