Review of the scientific and technological literature of fungicides in tannery industry: reducing the use and increasing the efficiency of fungicides in the leather industry

Content: One of the main challenges of the tannery industry chain is to reduce the use of biocides and restricted substances and at the same time increase efficiency with the available products. Such conduct must permeate suppliers and the tanneries in order to obtain better results, diminish the biocide resistance dissemination, optimize costs and be ecologically friendly. In this sense, we present herein an updated review and discussion of the scientific and technological literature on the aspects involving the action of fungicides in tannery industry and how the application of this knowledge can reduce application of biocides and restricted substances in the tanning process. We have organized a review by consulting the databases PUBMED, Web of Science, Science direct, and all literature with excellence scientific support available. The review focused on: (i) Fungal diversity involved in wet-blue biodeterioration; (ii) Mechanisms of action of fungicides; (iii) Fungicide combinations to enhance activity; (iv) Fungal mechanisms of resistance and the known causes of resistance emergence. As a result of this study we are able to track the fungal phylogenetics (and relationship) responsible for leather biodeterioration enabling a guiding strategy for fungal biocide application. Moreover, understanding of the mechanisms of action and interaction between molecules can determines the extent of the biocides inhibitory effect in different fungal species. Fungicide effect could vary, and such information corroborates with the idea that even in the same species the interaction of the different molecules may vary, possibly due to variation in cytochrome protein. For example, the most accepted mechanism of action of azoles is the inhibition of synthesis of or direct interaction with ergosterol (present in all fungi). Considering that the target is always the same, a question arise, how do the distinct azoles present different activities upon fungal strains? As result of this study we show that structural differences will influence the higher or lower interaction of the azole functional group and consequently the activity. The appropriated knowledge of the mechanisms by which microbial cells might develop resistance, highlights the need for an improved understanding of the reasons for their emergence and greater attention to methods that can be used to prevent and control them. In this sense, a successful combination of biocide molecules enhances a synergetic effect, avoiding fungal mechanisms of resistance and reduces dosage of each compound, being effective against a variety of fungi. Take-Away: Transfer of knowledge from the author of the fundermentals of bicides and fungicides used within the leather industry and similar industries, their application methods and how to use in combination for maximum effect with minimum environmental impact