Biocidal Activity of Selected Preparations for Leather Protection

Abstract

This research work involved the selection of biocides for the antimicrobial treatment of leathers. The scope of the research work covered microbiological tests of leather samples tanned utilising the same technology, with microbiological treatment made using 9 different preparations, as well as a test of leather without biostabilisation. Commercial biocides taken for inwestigation were as follows: NS 500 – an aqueous solution of nanosilver 500 ppm, ODH – tea tree oil, and OP – orange oil. Preparations prepared by diluting the purchased products were as follows: S27-22 – an aqueous solution containing silver chloride and titanium dioxide, SH 22-27 – an aqueous solution containing zinc pyrithione, ST 99-19 – an aqueous solution containing dimethyltetradecyl [3-(trimethoxysilyl)propyl]ammonium chloride, SU – an aqueous solution containing polyhexamethylene biguanide, and SGP – a saturated solution of aluminum potassium sulfate. Also a preparation was made by combining NS 500 M250 – 500 ppm nanosilver solution and a 250 ppm copper colloid. Evaluation of the effectiveness of biostabilisation of the leather samples and antimicrobial activity of the preparations used was carried out. Staphylococcus aureus and Escherichia coli bacteria and Candida albicans, Aspergillus brasiliensis and Trichophyton mentagrophytes fungi were used in the study. The assessment of microbial growth on samples was carried out according to Polish standards. Assessment of the resistance to bacteria and C. albicans yeast was made according to the PN-EN ISO 20645: 2006 standard – a method of diffusion on an agar plate. Assessment of the resistance to A. brasiliensis and T. mentagrophytes fungi was made according to the PN-EN ISO 14119: 2005 standard. Among the tested preparations to protect leathers against the effects of microorganisms, overall efficacy was obtained for SH 22-27, NS 500 M 250, SU and ODH.

Antifungal Activity of Finished Chromium Tanned Leather Containing Thyme and Tea Tree Essential Oils

“…The leather protection against microbes at different stages of the tanning process does not make it completely resistant to microflora. The availability of various sources of nutrients stimulates spores to germinate, and then supports the growth of hyphae [1]. Also, a sufficiently high temperature and moisture content enhances bacterial and fungal colonisation by different microbes, such as Bacillus, Corynebacterium, Clostridium, Staphylococcus, Penicillium, Aspergillus, Paecilomyces, Candida and Cryptococcus.…”

“…In order to prevent the appearance and development of various types of microorganisms and to prevent damage to leather, it is treated with certain biocides. Antimicrobial agents (biocides) used in the leather industry can be classified as quaternary ammonium compounds, isothiazoles, halogenated organic compounds, such as 2-bromo-2-nitro-propane-1,3-diol, isothiazoles and halogenated organic compounds containing heterocycles, such as derivatives of benzothiazole [1]. Unfortunately, biocides currently used in the leather industry are generally harmful to human health and the environment, and their use has been or shall be restricted or even banned.…”

“…It affects consumers who are in contact with the products, penetrating through the clothes onto the consumer's skin, causing painful skin, dermatitis, including itching, irritation and redness. Therefore, the use of biocides for the protection of materials should be controlled within the scope of the dose applied and intended use of the final product [1]. Changes in consumers' preferences toward more natural products than synthetic ones stimulate also the use of natural products in the leather tanning process.…”

“…Essential oils are widely used as components of drugs, biologically active additives and dietary supplements, as well as in aromatherapy and the food and cosmetics industries [5,7]. In addition, there have been attempts worldwide to use essential oils as natural bioactive substances for protecting leathers in the tanning industry [1,2,5]. Širvaitytė et al (2012) investigated the possibility of using essential oils of Thymus vulgaris as an alternative preservative for chromium tanned leather.…”

“…These findings suggested that oregano essential oils could be used as bactericidal agents in the leather industry [2]. Falkiewicz-Dulik observed that tea tree oil preparation showed a good antibacterial effect with regard to S. aureus and E. coli, as well as biocidal activity against yeast-like fungi C. albicans and filamentous fungi with large inhibition zones of mould growth A. brasiliensis and dermatophyte T. mentagrophytes [1].…”