ISSN:
1432-0800
Source:
Springer Online Journal Archives 1860-2000
Topics:
Energy, Environment Protection, Nuclear Power Engineering
,
Medicine
Notes:
Conclusions From the toxicological premises discussed the main aspect appears to be the contrasting signs of metabolic activation (high RNA levels, increased oxygen consumption) that the microorganism develops in the presence of PCBs, and the fact that such signs are not accompanied by a higher rate of biomass synthesis but quite the opposite. At least a partial explanation of the problem may be deduced from two main aspects of the inductive process: Firstly, as the PCBs are not transformed by interaction with the microorganism (Murado et al. 1976) their inductive activity must be considered unjustified or gratuitous. Secondly, taking into account that enhanced metabolism of aldrin, DDT, and pentobarbital is determined by the presence of structures that operate as unjustified inducers, we suggest such metabolism may be qualified as “allo-inductive”. It appears obvious, then, that PCBs as “alloinducers” are able to generate a considerable change in the energetic economy of the microorganism. Even supposing that the induced enzymatic system does not act on the endogen fungal components, it must be borne in mind that the inductive PCBs, on resisting the attack of the induced system, compels the microorganism in a sustained way to divert a fraction of its own disponsable energy towards the synthesis of a series of highly complex components. If, from the point of view of its formal biological meaning, the response developed byA. flavus is a consequence of a detoxifying function, its inefficacy against the PCBs may be identified as a stereotyped and non-specific reaction, whilst if the toxic effects increase in parallel with the response the reaction can be considered prejudicial.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02026995
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