Selection of Microorganisms

Many of the materials currently under development draw their inspiration from structures found in nature. That is, by mimicking the supramolecular architecture of natural materials, one can prepare complex materials capable of highly sophisticated functions. An important aspect of this work involves the selection of microorganism templates (e.g., diatomite) based on specific porous structures that may benefit targeted applications. 

Literature on microbial physiology and biochemistry may be helpful for the choice of strains to find enzymes for the biotransformation of naturally occurring substances. Screening of enzymes to convert unnatural compounds however usually implies an accidental selection of microorganisms. Actually, even such a preliminary approach gives valuable informations about the occurrance of an enzyme activity. 

The oxidoreductases of synthetic value can be grouped into four main supply categories. These are (i) fully or partially purified enzymes, (ii) yeasts, (iii) other microorganisms, and (iv) mammalian sources. Mammalian enzymes usually have broader specificities than those of microorganisms, but this is compensated for by the much larger selection of microorganisms available. 

Hexetidine has been quantitatively determined in both commercial formulations and saliva using a reversed-phase HPLC method, with determination being possible at concentrations below the published minimum inhibitory concentrations for a selection of microorganisms. 

Carroad P.A., Tom R.A., 1978. Bioconversion of shellfish chitin wastes Process conception and selection of microorganisms. J. Food Sci. 43 1158-1161. 

Knoshaug EP, Zhang M. (2009). Butanol tolerance in a selection of microorganisms. Appl Biochem Biotechnol, 153, 13-20. 

Screening and selection of microorganisms producing PHB is the first step in the bioprocess development of PHB. Several screening protocols have been developed to detect PHB in microbial cells. PHB confers some opacity to the bacterial cells thus allows a primary screening of PHB positive and negative colonies. This effect is only observed when the... 

Soil texture, structure and organic matter content give soil a certain water-holding capacity which has a strong influence on the selection of microorganisms humidity promotes the formation of bacterial colonies whereas dryness promotes fungal... 

Historically, the selection of microorganisms that produce enzymes has been empirical, starting with samples from very diverse natural sources. Cultures enriched by growth on substrates were used to inoculate fermentations. In a later stage, pure bacterial strains were selected. Intellectual property protections associated with bioprocesses have hampered the taxonomical characterization of industrially used strains. For the same reason, it is not always possible to trace the origin and history of currently used organisms. Once it... 

Carroad, P. A. and Tom, R. A. 1978. Bioconversion of shellfish chitin v astes process conception and selection of microorganism. J. 

Alikhanian, S. I. Induced mutagenesis in the selection of microorganisms. Advances in Appl. Microbiol. 4, 1 (1962). 

This section focuses on the optimization of key parameters such as selection of microorganism, precursor, medium and fermentation conditions. Experimental standard procedures such as organism development, procedures for inoculation, processing, work-up and purification are beyond the purview of this book. 

The role of redox potential (Eh) is much less known, particularly due to the difficulty of measuring it. However, it intervenes in the oxidation reactions of lipids and proteins, in the selection of microorganisms aerobic microorganisms that grow when Eh is positive or anaerobic when Eh is negative. 

A. Selection of Microorganisms that Convert Isobutyric Acid to p-Hydroxylsobutyric Acid [21]... 

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