December 2019 Abstracts

Innovative Approach to Sustainable Leather Tanning Process using a Lactic Acid Based Agent

by Malgorzata Kowalska, Anna Zbikowska and Magdalena Wozniak

The objective of the present study was to evaluate selected properties of leather samples treated with innovative lactic acid-based agents, applied during the soaking process. The quality of leathers soaked in the baths containing agents based on the organic lactic acid was compared to the products obtained by traditional tanning, in which surfactants were used during the leather soaking process. The obtained results showed that the hides soaked using the eco-compound met the same quality requirements as those soaked in traditional surfactants. The study has proven that the surfactants, which are universally applied during the traditional leather tanning technology, can be replaced with an environmentally friendly agent which effectively reduces effluent pollution as well as its quantity. The proposed method has been successfully tested by one of the largest tanneries in Poland and is in the process of implementation, thus becoming an ecotechnology.

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Enzymatic Reactions and Phylogenetic Analysis of Haloversatile Bacteria Isolated from Çamalti Saltern Salt Samples used in the Leather Industry

by P. Caglayan

Çamalti Saltern is one of the large seawater-based saltern located in Izmir, Turkey. The crude solar salt from Çamalti Saltern is used in leather industry. This type of salt may harbor viable microbial population which can spoil leather products during the curing process for hide/skins. Therefore, the objectives of this research were to isolate haloversatile bacteria from salt samples collected from Çamalti Saltern, to identify these isolates using both conventional and molecular methods, and to determine their hydrolytic enzymes such as protease, lecithinase, cellulase, lipase, deoxyribonuclease, pullulanase, amylase, urease, caseinase, xylanase and esterase. In addition, damage caused by lipase and protease producing haloversatile bacteria to the structure of salted sheep skins was examined. The effects of different salt concentrations, pH and temperature values on the growth of haloversatile isolates were also investigated. Sixty-nine isolates of aerobic Bacteria showing different colony morphology, pigmentation, colony shape, and size were selected for characterization of the isolates. Phylogenetic analysis showed isolates belonging to the genera Staphylococcus (9 species), Exiguobacterium (3 species), Bacillus (11 species), Microbacterium (3 species), Gordonia (1 species), Kocuria (3 species), Paracoccus (2 species), Micrococcus (2 species), Acinetobacter (1 species), Brevibacterium (1 species), Pseudomonas (1 species), Agrococcus (1 species), Sanguibacter (1 species) and Virgibacillus (1 species). The haloversatile isolates were able to produce different enzymes such as catalase (100%), oxidase (80%), protease (52%), lecithinase (51%), cellulase (33%), lipase (23%), deoxyribonuclease (17%), pullulanase (10%), amylase (7%), urease (4%) and caseinase (4%). Scanning electron micrographs of sheep skins showed that catabolic activities of haloversatile bacterial species found in crude salt were responsible for decomposition of skins. When the crude salt containing haloversatile bacteria is used as a preservative for skins, these haloversatile bacteria may damage skin structure.

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The Suitability of Leather as an Alternative Material for Sustaining Vessel Production in Ghana

by Baidu, K. A. O., Essuman, E. K., Asubonteng, K, Boahin, J. O. B.

Anecdotal evidence and a further report from leather experts show that there is close to no enlightenment of the production of leather vessels in Ghanaian leather industries. This study was, therefore, conducted as a result of the need to add leather as supplementary material to the traditional materials such as clay, metal, wood and half-gourd used for producing vessels in Ghana. The purpose of the study was to find out how Ghanaian indigenous leather could be used in the production of leather vessels. The qualitative study employed three key techniques, namely: ‘Cuir bouilli’ leather hardening methods, the sand pounding technique, and assemblage and construction technique. Based on the results, the baking and hot wax methods adversely affected the indigenous leather positively in the hardening of the leather. The results also show that using only one part of the leather (the back, belly or butt) affected the quality of the leather vessels, but incorporating the various parts of the hide helped improve the quality and durability of the leather vessels. The implications of the results and future research directions are also presented. This study has, therefore, expanded the usefulness of the Ghanaian indigenous vegetable tanned leather apart from the conventional usage for making shoes, bags and belts.

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Closed-Loop Processing: Management in Existing Tanneries and New-Builds Designed for Purpose

by Richard Daniels, Jiasheng Su, Falei Zhang, Zhuangdou Zhang

Closed-loop processing for unhairing/liming and tannage is established technology for the processing of raw hides to the wet blue state.

This approach produces a high value product and, as part of sustainable manufacture, is significant. Savings are gained in chemicals, water and energy and reductions in the wastewater load. In effluent treatment, both the sulfide oxidation stage and chrome recovery/regeneration systems are eliminated. Both sulfate and chloride are minimised, and a reduction in solid waste generation.

In November 2018 new-build tanneries with radically different layouts were at an advanced stage of construction and installation of new equipment. These were designed to management and technical requirements of this specific technology.

In addition, the technology had made the transition from bovine manufacture to nappa leathers production in a major sheepskin tannery. And within small scale operations – bovine hides, bovine bellies, sheep and goat skins - chrome tannage was taking place with processing adapted around the prevailing conditions and tanners requirements.

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