EDITORIAL EJB ELECTRONIC JOURNAL OF BIOTECHNOLOGY ....MOVING FROM SCIENCE TO
DEVELOPMENT... |
Bioprocess and Functional Genomics At the onset of the twenty first century, biological systems of biotechnology are diverse, including microorganisms, established cell lines of animal and plant origin, organs as transformed roots, enzymes and even whole living animals and plants. Using such diverse systems to develop a process technology or a product is the ultimate task of our research in biotechnology. Experimental design, modeling and molecular biology are indispensable elements of our research toolbox. However, insufficient knowledge in molecular biology, biochemistry and cell physiology is common. This leads us to approach biological systems as a black box, making empirical strategies to optimize product yield, not knowing certainly why a variable is important and what are the effects on gene expression and metabolism. Metabolic engineering is a first structured approximation to an integral understanding of complex biological systems. It considers cell metabolism as a network of biochemical reactions, and allows to determine how the rate variation of a single reaction can affect others within the network In this way it is possible to envision that the yield of a certain metabolite can be increased substantially by metabolic flux redistribution, which may include the activation of alternative metabolic pathways and cloning of exogenous enzymes not regulated by the host metabolic control system. However, this analysis is usually oversimplified because of insufficient data on enzyme kinetics of the involved reactions and the incomplete information on the mechanisms of transport of substrates and metabolic intermediates. The global impact of metabolic flux redistribution on the biological system is also difficult to predict and new tools are needed to visualize a complex biological system as a whole. Functional genomics, through transcriptomes and proteomes is a very promising alternative to gather information on how the whole biological system will respond to changes in environmental conditions, i.e., how the nutrient concentration, temperature, dissolved oxygen and carbon dioxide will affect the expression of functional genes for protein synthesis. However, genome and protein maps are not available for most organisms of biotechnological potential, with the notable exceptions of Saccharomyces cerevisiae and Bacillus subtillis. This seems to be no longer a limitation in view of the present state of the art in gene sequencing. Besides, the option of working with related species exists and microarrays of complete genomes or the analysis of all proteins synthesized by the cell are not always needed. As biotechnologists, we are now confronted to the challenge of using transcriptomes and proteomes for production purposes. Process optimization based on the knowledge of the effect of process variables on gene expression and protein synthesis is now a dream ready to come true. |
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Mayra de la Torre |