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Resistant fungus strains from a mining zone polluted with heavy metals.
It's known that fungus acquire resistance in an environment rich in heavy metals. In this way, some years ago Crisophorum pannorum a fungus which parasites grass roots, acquired resistance to Tampocose, a comercial fungicide which active principle is a mercury based organic compound.
Recently it has been found that Rhizopus stolonifer and Cunningamela blakesleana, two common zygomycete species, acquired resistance to copper, cadmium, nickel, lead and cobalt when grown in media with high concentration of this heavy metals. Tolerance to copper was unstable in absence of metal, this were carried out together with changes at molecular level, like wall protein and glutamate synthesis; glutamate can sequester metals.
This work is part of the project entitled "Ecological impact of the mining activity at central mexico". Thus, we are studying the microflora existing around mining wastelands in order to determine the impact of this pollution for the local biota. The results exposed here come from the very first study performed at the Angangueo mining zone located east Michoacán.
The fungus were collected from a polluted area at the mining zone of Angangeo and homogeneous strains (microscopically and macroscopically) were isolated. Different genera strains like Aspergillus, Trichoderma, Penicillium, Gliocadium, Mucor, Mortierella and Cunninghamella were isolated. The taxonomic and evolving difference allowed us to conclude that tolerance systems are an extended phenomena, this was confirmed with earlier observations in Bidens odorata. This diversity is evident when comparing response and adaptation patterns of each isolated strains.
The fungus studied here are not rare species, instead are widely spread fungus in nature and make asexual reproduction a way of fast reproduction with no zygotic union.
Next, we have added links to detailed descriptions of the experiments performed to detect heavy metal resistant fungus strains from mining zones.
Contaminación por metales pesados y su influencia en la evolución.
Exposed in the Congreso Mexicano de Microbiología, Morelia, Michoacán Marzo de 1989
