Production of poultry feather hydrolysate using HCl and NaOH as a growth medium substrate for indigenous strains

The poultry feathers have a very high protein content due to it consists of 90% of crude protein, and it is an ideal material to obtain keratin protein. Due to Keratin’s difficulties and time-consuming decomposition, further processing is needed to degrade Keratin into simpler proteins that can be used as an alternative N-source. This study was aimed to evaluate the keratin hydrolysate from poultry feathers prepared by acidic (HCl) and alkaline (NaOH) compound utilization and its potency as the substrate medium for growth keratinolytic bacteria at a laboratory scale. Poultry feathers, including kampung (local breed) chicken feathers, layer chicken feathers, and local goose treat with HCL 12% and NaOH 20%. The results of the hydrolysate of poultry feathers using 12% HCl showed no significant changes. Visually, the feathers of birds that have been treated with 12% HCl show a colour change to brownish-yellow. The results of hydrolysis using NaOH showed better results than HCl for producing feather meals. The highest yield has occurred at local goose feathers at 95.7%, followed by Kampung and Layer chicken feathers at 93.17% and 78,75%. Based on the viability test, three indigenous strains (Bacillus cereus TD5B, B. cereus LS2B and Pseudomonas sp. PK4) grew in a medium with a substrate of kampung chicken feathers, layer chickens, and local goose feathers. It can be concluded that the hydrolysed poultry feathers made by NaOH 20% preparation had a potency as N-source in the bacterial growth medium.

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.

Autogenous Cross-Linking of Recycled Keratin from Poultry-Feather Waste to Hydrogels for Plant-Growth Media

The global rise in atmospheric temperature is leading to an increasing spread of semi-arid and arid regions and is accompanied by a deterioration of arable land. Polymers can help in a number of ways, but they must not be a burden to the environment. In this context, we present herein a method by which goose feathers, representative of keratin waste in general, can be transformed into hydrogels for use as a plant growth medium. The treatment of shredded feathers in Na2S solution at ambient conditions dissolves approx. 80% of the keratin within 30 min. During evaporation, the thiol groups of cysteine reoxidise to disulphide bridges. Additionally, the protein chains form β-sheets. Both act as cross-links that enables the formation of gels. The drying conditions were found to be crucial as slower evaporation affords gels with higher degrees of swelling at the cost of reduced gel yields. The cress germination test indicated the absence of toxic substances in the gel, which strongly adheres to the roots. Thereby, the plants are protected from drought stress as long as the gel still contains moisture.

Efficient isolation of keratin from protein rich waste biomass: A practical approach to minimize environmental impact and valorize waste biomass

Among protein-containing biomass waste, waste animal wool, poultry feather, and human hair are considered as one of the most important renewable sources of keratin. Although waste animal wool (WAW) and human hair (WHH) are used for the production of number of products but the substantial quantity of short fibers not suitable for spinning and being unusable is thrown as waste resulting considerable environmental problem in terms of their accumulation in water bodies resulting water clogging and other related problems. Similarly, poultry waste especially the waste chicken feathers (WCF) is dumped or burnt, or used as low value fertilizer in certain applications. To extract more value-added products such as keratin from such wastes, herein suitability of an aqueous solution of quaternary ammonium hydroxide known as tetramethylammonium hydroxide (25% w/w TMAOH in water) to solubilize these protein wastes and to extract keratin from them was investigated. The solvent could solubilized ca. 39–44% w/w of WAW, 19–25% of WHH, and 55–60% of WCF. Crude keratin with ca 19–20%, 35–37%, and 69–74% were isolated from WAW, WHH, and WCF respectively. The chemical and structural stability of keratin thus isolated was established. The recovered TMAOH, insoluble WAW and WCF were found to be nontoxic to soil microbes. The recovered TMAOH thus generated after isolation of keratin was used for green gram (Vigna radiata) seed treatment and a substantial increase in the height (4–12%) and weight (9–58%) of the plants were observed. Treating biomass waste as a source of high value compounds may minimize environmental impact by reducing the waste load.

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).

Monascin and monascinol, azaphilonoid pigments from Mortierella polycephala AM1: in silico and in vitro targeting of the angiogenic VEGFR2 kinase

The fungus, Mortierella polycephala is one of the most productive sources of anticancer bioactive compounds namely those of pigment nature. During our investigation of the produced bioactive metabolites by the terrestrial M. polycephala AM1 isolated from Egyptian poultry feather waste, two main azaphilonoid pigments, monascin (1) and monascinol (2) were obtained as major products; their structures were identified by 1D (1H&13C) and 2D (1H–1H COSY, HMBC) NMR and HRESI-MS spectroscopic data. Biologically, cytotoxic activities of these compounds were broadly studied compared with the fungal extract. To predict the biological target for the presumed antitumor activity, an in silico study was run toward three proteins, topoisomerase IIα, topoisomerase IIβ, and VEGFR2 kinase. Monascinol (2) was expected to be moderately active against VEGFR2 kinase without any anticipated inhibition toward topo II isoforms. The in vitro study confirmed the docked investigation consistently and introduced monascinol (2) rather than its counterpart (1) as a potent inhibitor to the tested VEGFR2 kinase. Taxonomically, the fungus was identified using morphological and genetic assessments.

Poultry feather disulphide bond breakdown to enable bio-based polymer production

With oil supplies, needed for plastic production, decreasing dramatically, there is a clear driver for alterative polymers from sustainable resources. Poultry feathers, containing ∼90% keratin, are one source of natural polymer with huge potential for biopolymer production. However, the presence of crosslinks, known as disulphide bonds, hinders processability. This paper reviews techniques to enable breakage of disulphide bonds through use of reduction agents (sodium sulphite and sodium sulphate) and hydrolysis. Samples were analysed using FTIR and DSC to quantify achievable bond breakage, effect on thermal properties and changes in protein concentration. A review on the effect of particle size on disulphide bond breakage was also conducted, along with quantifying the reformation of bonds post-processing. Finally, a bicinchoninic acid (BCA) protein assay was used to quantify changes to soluble protein content, key to predicting if biopolymer formation can occur. The results showed a final disulphide bond breakage of between 48% and 67% was achievable using these techniques. It was also shown that disulphide bond content exhibited up to 60% bond reformation post treatment. These reductions in disulphide bonds increased the thermoplastic nature and apparent protein content. Despite achieving the highest bond breakage percentage, hydrolysis caused degradation of useful proteins, rendering the material unsuitable for biopolymer production. Results suggested that treatment with sodium sulphite (4.3% wt. of feathers) and use of a small particle size (0–100 µm), sufficiently altered the properties of raw feathers to enable feather biopolymer production.