Content:
The leather industry has been challenged to reduce its environmental impact, for example, by producing eco-friendly products with inherent biodegradability using less polluting chemicals. Conventional depilation of hair and wool consumes a large amount of lime and sodium sulphide, which poses a serious waste disposal concern. Volatile organosulphur compounds remaining in leather products may provoke an unpleasant odour and be the cause of a deterioration in indoor air quality. Traditional leather production also generates tanned waste which cannot be readily degraded by microorganisms.
LASRA research is guiding the application of biotechnology to help the New Zealand leather industry develop environmentally sustainable leather processes, replacing hazardous chemicals with microbial
enzymes. Using 16S rRNA gene sequencing, we have isolated and identified a number of indigenous bacteria from the leather industry environment which are being adopted to develop benign leather
processing technologies. We discovered a strain of Stenotrophomonas spp. with significant and beneficial proteolytic activity in a tannery sludge. The identified strain not only displays collagenase activity but also the ability to reduce hexavalent chromium to trivalent chromium, making it an ideal candidate for biodegradation of tanned waste. We also isolated and identified several Bacillus spp. strains from a
biofilter used in a leather manufacturing plant which exhibited sulphide oxidation activity, which are being applied in bioremediation of volatile organosulphur compounds emitted by leather products. Recently we revisited the natural autolytic processes of degradation of untreated pelts to guide a natural depilation method without any need for additional chemical treatment. The characterisation of the bacteria isolated from the skins showed the alkaline protease production activity responsible for the observed nature unhairing. We found that in controlled experiments the wool could be removed completely from follicles after 2 days, without obvious damage and leathers could be processed with organoleptic and mechanical properties comparable to conventionally processed counterparts. With the mechanisms revealed, the natural depilation can be controlled to become more reliable and reproducible across a range of conditions. Our current work is focused on the development of solid-state fermentation using skin and leather waste as a culture medium to produce the required enzymes to make biological leather production practical and reproducible. Our research is aimed at enabling the NZ leather industry to produce highquality leather products with a much-reduced environmental footprint.
Take-Away:
1. Indigenous bacteria have been isolated and identified from the leather industry environment by the application of 16S rRNA gene sequencing.
2. Biodegradation of tanned waste and bioremediation of volatile organosulphur compounds are being developed.
3. The mechanism of natural depilation has been revealed and the application of enzymatic depilation can become practicable by using solid-state fermentation.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:34329 |
| Date | 28 June 2019 |
| Creators | Liu, John, Holmes, G. |
| Contributors | International Union of Leather Technologists and Chemists Societies |
| Publisher | Verein für Gerberei-Chemie und -Technik e. V., Forschungsinstitut für Leder und Kunststoffbahnen (FILK) gGmbH |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, doc-type:conferenceObject, info:eu-repo/semantics/conferenceObject, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | urn:nbn:de:bsz:14-qucosa2-340872, qucosa:34087 |
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