The cellulase activity of the fungi that grow on the bio-based thermal insulation composite materials

Bio-based thermal insulation materials are ecological materials made from a hemp, flax, jute,
wood wastes. Such composites also consist the corn starch, the poly-L-lactide or natural lignin as the binders.
Such materials are the environment-friendly, but under their exploitation the biodestructive factors arrise. At
certain conditions like high humidity or the occumulation of moisture, such kind of materials may be
susceptable to the microbial action which can lead to the changes of physical-chemical properties of materials,
their destruction, and also the human health problems.
In this work, we isolated and identified several fungal strains that grow on hemp-shives based
biocomposite boards. Such boards were made of the hemp fibres with the naturally present lignin, and either
the corn starch or the acrylate resin Acrodur 9501 binders. Using sequencing of the ribosomal ITS regions, we
identified the belonging to the Rhizopus oryzae, Sporothrix schenckii, Talaromyces pinophilus, Aspergillus
fumigatus, and Trichoderma spp. genera. Such fungi were expected to use the cellulase as the carbon and
energy source, therefore the initial detection of the cellulase activities was determined by the Gram‘s iodine.
The cellulase activities were subsequently determined for A.fumigatus using the 3,5-dinitrosalicylic acid ( DNS
method). The cellulase activity was detected when the composite boards with A.fumigatus were immersed into
the distilled water compared to the growth of these fungi in Czapek medium or natural corn starch medium