Abstract
Background: Keratin-rich materials pose significant environmental challenges due to their accumulation across various industries, particularly in poultry farming, which generates
extensive amounts of feather waste annually [1]. Traditional waste management strategies such as incineration and landfill disposal are unsustainable, emphasizing the need for alternative solutions. Keratin’s structural complexity, characterized by tightly packed α-helices and βsheets stabilized by disulfide bonds, makes it highly resistant to degradation by conventional proteases [2]. However, microbial keratinases, have demonstrated the ability to efficiently hydrolyze keratin into soluble proteins, peptides, and amino acids. These enzymes often act synergistically with disulfide reductases and cysteine dioxygenases, facilitating more efficient keratin degradation [3]. Given the energy-intensive nature of industrial enzymatic processes, cold-adapted enzymes offer a promising solution by reducing the need for high temperatures.
Arthrobacter oryzae, originally isolated from Antarctic green snow, exhibits efficient keratin degradation at temperatures below 30°C [4].Methods: This study followed a genomics and proteomics-based approach, utilizing a filter plate assay [5] to isolate the secreted enzymes, using feather meal as a substrate. The resulting secretome was compared to the newly sequenced A. oryzae genome, enabling the identification of specific enzymes involved in keratin degradation at different timepoints. This analysis was put in parallel with the secretome of Bacillus licheniformis, a known keratin degrader [3], comparing their mode of action.
Results: The results show a difference in the strategy of the two studied bacteria in keratin degradation. A. oryzae seems to employ a unique enzymatic strategy mostly focused on
intracellular degradation, with a low amount of secreted proteins and employing more transporters than B. licheniformis which employs mostly secreted proteases. By analyzing this
novel enzymatic cocktail, we aim to unravel a different mechanism of feather degradation, potentially revealing new insights into keratinolytic processes and expanding the biotechnological potential of A. oryzae in sustainable waste management. Biography: Clémentine Isembart is a PhD candidate at the Norwegian university of life science
(NMBU) focusing on the microbial hydrolysis of feather for industrial application. The project aims to optimize and enravel the keratin degration mechanisms of bacteria and fungi. The
project is funded by the research council of Norway, through SFI IB, in collaboration with industries.
References:
[1] Tesfaye et al. “Valorisation of chicken feathers: a review on recycling and recovery route—current status and future prospects” [2] Zhang and Fan, “Structure of Keratin.” [3] anoksilapatham and Intagun “A Review: Biodegradation and Applications of Keratin Degrading Microorganisms and Keratinolytic Enzymes, Focusing on Thermophiles and Thermostable Serine Proteases”. [4] Smirnova et al. “New Cold-Adapted Bacteria for Efficient Hydrolysis of Feather Waste at Low Temperature.” [5] Bengtsson et al. “A novel proteomics sample preparation method for secretome analysis of Hypocrea jecorina growing on insoluble substrates”