Abstract
Feather degrading bacteria from birds' nests were
characterized to find safe bacterial strains that could
be utilized to convert feathers into soluble form and
bacterial biomass for feed purposes. Of all tested 571
isolates 122 were keratinolytic. Partial sequencing of
the 16S rRNA gene revealed that the keratinolytic
isolates represented Proteobacteria (genera Pseudomonas
and Stenotrophomonas) and Firmicutes (genera Bacillus,
Exiguobacterium, Paenibacillus, Rummeliibacillus, and
Sporosarcina). Bacillus cereus group and gram-negative
bacterial isolates were not further characterized due to
safety concerns related to potential pathogenicity or
potential exposure of animals or workers to endotoxins
(lipopolysaccharide part of the gram-negative cell wall).
Keratinolytic strains showed clear differences in their
ability to solubilize feathers with feather weight losses
up to 30%. Amino acid composition of feather hydrolysates
shifted from feather composition towards more
bacterial-like composition. Especially the levels of
lysine could be increased in the feather hydrolysate with
bacterial fermentation. Feathers can be effectively
hydrolyzed with non-pathogenic bacteria without any
additional nutrients. The resulting feather hydrolysate
is easier to digest than feather material and it has an
improved amino acid composition regarding some limiting
amino acids. The amino acid content of the final product
can be tailored by varying the fermentation time and thus
the ratio of bacterial cells to the feather hydrolysate.
Original language | English |
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Pages (from-to) | 262-268 |
Journal | International Biodeterioration and Biodegradation |
Volume | 123 |
DOIs | |
Publication status | Published - 2017 |
MoE publication type | A1 Journal article-refereed |
Keywords
- keratinolytic bacteria
- feather
- bacillus
- feed
- lysine
- biomass