Metabolic activity, biotechnology

Bauer, S. A. W., Schneider, S., Behr, J., Kulozik, U., Foerst, P. (2012). Combined influence of fermentation and drying conditions on survival and metabolic activity of starter and probiotic cultures after low-temperature vacuum drying. Biotechnology for Enhancing Plant Production and Food Quality, 759(4), 351-357. 

Makri, A., Fakas, S., Aggelis, G., 2010. Metabolic activities of biotechnological interest in Yarrowia lipolytica grown on glycerol in repeated batch cultures. Bioresouice Technology 101, 2351-2358. 

One of the most actively investigated aspects of the biohydrolysis of carboxylic acid esters is enantioselectivity (for a definition of the various stereochemical terms used here, see [7], particularly its Sect. 1.5) for two reasons, one practical (preparation of pure enantiomers for various applications) and one fundamental (investigations on the structure and function of hydrolases). The synthetic and preparative aspects of enantioselective biocatalysis by hydrolases have been extensively investigated for biotechnology applications but are of only secondary interest in our context (e.g., [16-18], see Sect. 7.3.5). In contrast, the fundamental aspects of enantioselectivity in particular and of structure-metabolism relationships in general are central to our approach and are illustrated here with a number of selected examples. 

Polynucleotide polymerases attract much attention - not only because of their central role in DNA metabolism, which suggests an important link to various diseases like tumor growth, defects of the immune system, stress-associated mutagenesis, or viral infections. Several polymerases are indispensable tools for molecular biotechnology, and could be even more valuable if the range of substrates accepted, or their stability and activity, could be tuned to specific requirements. 

A notorious underestimation of the dynamic properties of microbial and cellular populations results from matching the duration of the respective batch cultivations to the relevant time constant of the biosystem under investigation. However, metabolic regulation of enzyme activities and fluxes often takes place on a time scale of seconds rather than days although the latter may also be true. It is therefore in the scope of promoting biotechnological research to adopt and develop appropriate experimental concepts, methodologies and equipment [397]. 

Edwin Lightfoot I have a few remarks on topics that may have been missed. First, we can divide biotechnology into the areas of bioprocessing, which is truly a chemical engineering activity, and metabolic engineering, where we re concerned with the details of the living organism. Both of these have big opportunities for us. 

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