Usefulness of biologically active

The search for and use of biologically active chemicals by man dates at least to the dawn of Homo sapiens, and doubtless to his ancestors. One can speculate about why such early human societies used such agents. Likely, anything that could provide relief from the undoubted harshness and danger of life - described by the 17th century English philosopher Thomas Hobbes as, poor, nasty, brutish, and short - would be considered desirable. This search for biologically active chemicals continues today, albeit at a more sophisticated and rational level. 

Edyvean, R. G. J., Thomas, C. J., Brook, R., and Austen, I. M., "The Use of Biologically Active Environments for Testing Corrosion Fatigue Properties of Offshore Structural Steels, Proceedings, Biologically Induced Corrosion, S. C. Dexter, Ed., NACE-8, National Association of Corrosion Engineers, Houston, TX, 1986, p. 254. 

In the published trials mistletoe extracts of different origin (host tree) and mode of preparations have been used. Assuming that the lectin VAA-1 is an active component, its content in the extracts varies with the host tree, the season of mistletoe harvest, the extraction procedure, the fermentation, etc. This makes the trials no longer comparable. The demand for future clinical research and trials is the use of biologically active and reproducibly standardized preparations. 

The first scientific study on antimicrobial properties of active compounds present in plants was published in the early 1920s (Hoffman and Evans 1911). The results of the first research on the use of biologically active compounds in ruminant nutrition come from the 1960s. Oh et al. (1967, 1968) and Nagy and Tengerdy (1964, 1968) described the influence of essential oils on fermentation processes in the rumen under in vitro conditions, including the production of postfermentation gases and activity of ruminal bacteria. 

This process combines the use of biological activated carbon with adsorption. The biodegradable organic matter, or biodegradable dissolved organic carbon, which enters with the raw water is transformed into carbon dioxide and biomass by heterotrophic bacteria fixed on the carbon. The biomass is then partially consumed by protozoa. An equilibrium is reached among the inflow of food, bacteria, protozoa and algae. This equilibrium must be carefully controlled in order to assure the... 

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