The effect of micromycetes (MM) Fusarium solani and Trichoderma lignorum on the biodegradation of plastics (sevilene, polystyrene, polyethylene, polyamide, polycarbonate, fluoroplast-4) after 10 years of exposure in an aqueous medium in a closed system was investigated. Differential scanning calorimetry showed that destruction was most complete in the case of polyamide, and less intense in the case of sevilen.
The cultivation of MM with these polymers led to a significant alkalization of the medium, an increase in the specific electrical conductivity and the concentration of inorganic ions in the aqueous suspension, which is associated with the vital activity of microbial cells. In a suspension of three polymers (polyamide, polystyrene, and polycarbonate) favorable conditions are created for the life of MM, especially for T. lignorum, which may indirectly indicate the possibility of using the products of destruction of these polymers by fungi as nutrients.
The maximum values of the content of suspended solids and the minimum coefficient of light transmission in the suspension, which indirectly indicate a greater mass of mycelium, are established for the variants of polyamide, polycarbonate and polystyrene with micromycetes.
The maximum content of organic substances in suspensions, determined by the COD index, was noted for samples of sevilene, polystyrene and polyethylene (control and with MM), the minimum – for samples of fluoroplast-4.
The proof of the MM viability after 10 years of exposure was the powerful growth of mycelium on the surface of the nutrient medium in all variants during their microbiological inoculation, which indicates that the studied polymers served as a carbon source for fungi for a long time.
The results of the study showed that the polymers most utilized by the studied types of ММ were polyamide, polycarbonate and polystyrene. To accelerate the biodegradation of polymers, it is necessary to optimize the conditions, in particular, to carry out the process with the introduction of certain nutrients that accelerate the growth of MM.
ISSN 1995-4301
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