In vitro utilization of L-cystine by keratinophilic fungi inhabiting a gelatin factory

Biodegradation of keratin waste: Theory and practical aspects

Keratin-rich by-products, i.e. bristles, horns and hooves, chicken feathers and similar, are a source of nutrients for animals (amino acids) and plants (N, S). Contemporary developments in the management of keratin waste in feeds and fertilizers comply with human and animal health protection regulations and respect the principles of ecological development. Biotechnological methods employing keratinolytic bacteria and microscopic fungi play a key role in processing keratin waste. This study reviews the current knowledge on the ecology and physiology of keratinolytic microorganisms and presents the biodegradation mechanism of native keratin. The structure and chemical composition of keratin proteins are described, and methods of keratin waste biotransformation into products of practical industrial and natural value, especially composts, are discussed.

Biodegradation of wool by Trichophyton simii and Aspergillus niger

The amount of protein released into liquid culture medium and weight loss were taken as measures of wool degradation by Trichophyton simii and Aspergillus niger. Protein released into the culture medium was observed to be greater after T. simii treatment than after A. niger treatment. Sulphitolysis was shown by T. simii, whereas it was absent in the case of A. niger, pH was found to be alkaline with an increase in soluble protein in the culture medium in the case of both uniculture and dual culture. However, both the weight loss of wool and the amount of protein released were significantly reduced when both fungi were allowed to attack the substrate. The behaviour of these fungi in dual culture reflects their antagonistic activities.