Fungal decomposition of chicken-feather waste in submerged and solid-state fermentation

Poultry industry is expanding rapidly and producing million tons of feather waste annually. Massive production of keratinaceous byproducts in the form of industrial wastes throughout the world necessitates its justified utilization. Chemical treatment of keratin waste is proclaimed as an eco-destructive approach by various researchers since it generates secondary pollutants. Keratinase released by a variety of microbes (bacteria and fungi) can be used for the effective treatment of keratin waste. Microbial degradation of keratin waste is an emerging and eco-friendly approach and offers dual benefits, i.e., treatment of recalcitrant pollutant (keratin) and procurement of a commercially important enzyme (keratinase). This study involves the isolation, characterization, and potential utility of fungal species for the degradation of chicken-feather waste through submerged and solid-state fermentation. The isolated fungus was identified and characterized as Aspergillus (A.) flavus. In a trial of 30 days, it was appeared that 74 and 8% feather weight was reduced through sub-merged and solid-state fermentation, respectively by A. flavus. The pH of the growth media in submerged fermentation was changed from 4.8 to 8.35. The exploited application of keratinolytic microbes is, therefore, recommended for the treatment of keratinaceous wastes to achieve dual benefits of remediation.

Keratinases as Versatile Enzymatic Tools for Sustainable Development

To reduce anthropological pressure on the environment, the implementation of novel technologies in present and future economies is needed for sustainable development. The food industry, with dairy and meat production in particular, has a significant environmental impact. Global poultry production is one of the fastest-growing meat producing sectors and is connected with the generation of burdensome streams of manure, offal and feather waste. In 2020, the EU alone produced around 3.2 million tonnes of poultry feather waste composed primarily of keratin, a protein biopolymer resistant to conventional proteolytic enzymes. If not managed properly, keratin waste can significantly affect ecosystems, contributing to environmental pollution, and pose a serious hazard to human and livestock health. In this article, the application of keratinolytic enzymes and microorganisms for promising novel keratin waste management methods with generation of new value-added products, such as bioactive peptides, vitamins, prion decontamination agents and biomaterials were reviewed.

Poultry Feather Waste as Bio-Based Cross-Linking Additive for Ethylene Propylene Diene Rubber

Most rubbers used today rely on sulphur as a cross-linking agent and carbon black from fossil resources to modify the mechanical properties. A very promising substitute can be found in natural keratins such as feathers. These are not only tough, but also contain a relevant amount of sulphur in the form of disulphide bridges. The present study shows that these can be activated under vulcanisation conditions and then bind covalently to EPDM rubber to form a cross-linked network. Feathers were cut into lengths of 0.08, 0.2, and 1 mm and incorporated at 38, 69, or 100 phr into EPDM mixtures containing either no carbon black or no carbon black nor sulphur. The presence of feather cuttings increases the tensile and compressive strength as well as the hardness, and reduces the rebound resilience. Due to their high (approximately 17%) nitrogen content, the feathers also improve the thermal stability of the composite, as the main degradation step is shifted from 400 °C to 470 °C and the decomposition is significantly slowed down. Since elastomers are a large market and feathers in particular are a high-volume waste, the combination of these two offers enormous ecological and economic prospects.

Biogeneration and physico-chemical properties of panchagavya fortified chicken feather vermicompost

An enormous amount of chicken feather waste materials released by the poultry industry creates severe environmental pollution. Vermicomposting is an eco-friendly way to degrade chicken feather waste along with microbial mixture (Panchagavya). Chicken feather waste was pre-decomposed by mixing it with fresh cow dung (T1), dry cow dung (T2), and Panchagavya (T3). Among these, T3 exhibits rapid deterioration of chicken feather waste and seven combination T3 substrates (E0-E6), taken for the vermicomposting process by Eudrilus eugeniae in 60 days. Scanning Electron Microscopy/Energy Dispersive Spectroscopy (SEM-EDS) and Fourier Transforms Infrared (FT-IR) Spectroscopy are used to assess compost maturity. The result shows that E1 (0.050:1 ratio) shows various functional groups, rich nutrients, and necessary acids than other combinations. For large-scale commercial vermi-stabilization of chicken feather waste, the E1 combination is suitable for manure production and thereby enhances soil fertility, agricultural production.

Chryseobacterium pennae sp. nov., isolated from poultry feather waste

A Gram-stain-negative, rod-shaped, non-motile, non-spore-forming, aerobic, yellow-pigmented bacterium was isolated from chicken feather waste collected from an abattoir in Bloemfontein, South Africa. A polyphasic taxonomy study was used to describe and name the bacterial isolate, strain 1_F178T. The 16S rRNA gene sequence analysis and sequence comparison data indicated that strain 1_F178T was a member of the genus Chryseobacterium and was closely related to Chryseobacterium jejuense (99.1%) and Chryseobacterium nakagawai (98.7%). Overall genome similarity metrics (average nucleotide identity, digital DNA–DNA hybridization and average amino acid identity) revealed greatest similarity to the C. jejuense and C. nakagawai type strains but were below the threshold for species delineation. Genome sequencing revealed a genome size of 6.18 Mbp and a G+C content of 35.6 mol%. The major respiratory quinone and most abundant polar lipid of strain 1_F178T were menaquinone-6 and phosphatidylethanolamine, respectively. Strain 1_F178T had a typical fatty acid composition for Chryseobacterium species. On the basis of physiological, genotypic, phylogenetic and chemotaxonomic data, strain 1_F178T constitutes a novel species of Chryseobacterium , for which the name Chryseobacterium pennae sp. nov. is proposed. The type strain is 1_F178T (=LMG 30779T=KCTC 62759T).