The impact of water-soluble guanidine-containing (co)polymers on aspergillus niger and the assessment of their efficiency

The presented work examines the effect of modified water-soluble guanidine -containing (co)polymers on a strain of the mold Aspergillus niger (A. niger). It has been established that the main component of widely used biocides, polyhexamethylene guanidine hydrochloride (PHMGgx), is the least effective at inhibiting the growth of mold fungi, and an increase in the content of octamethylene fragments in the macromolecular structure, that is, an increase in hydrophobicity, leads to an increase in the fungicidal effect and completely suppresses the growth of fungal cells. Laboratory experiments were carried out to study the effect of (co)polymers when they were added to a nutrient medium in Petri dishes, as well as when the surface was treated with solutions of different concentrations of a real object - healthy Scots Pine (Pinus sylvestris) wood. It was determined that the maximum inhibition of A. niger growth is achieved on a nutrient medium containing 30 and 50% octamethylenediamine, which is comparable to the data obtained when assessing the fungicidal effect on Pinus sylvestris wood. In the course of the study, the obtained dependences suggest a mechanism for the interaction of the fungal cell wall with the (co)polymer, where at the first stage of exposure, sorption of polymer macromolecules by the fungal cell wall membrane occurs due to the proteins contained in it - << adhesins >>, followed by a violation of the integrity of the cell and ends with osmotic lysis. The effectiveness of the studied compounds was assessed and their classification was made according to the degree of protective properties against wood damage by moldy fungi. According to the classification, the studied modified water-soluble guanidine -containing (co)polymers are effective and highly effective means of protective ability to resist infection of the wood surface by mold fungi.