Evaluation of waste chicken feathers as peptone source for bacterial growth

Peptones are one of the most expensive constituents of microbial media. This study was undertaken to prepare the peptone from waste chicken feathers through a new process.

The chemical analysis of chicken feather peptone (CFP) was performed. The ability of CFP to support the growth of the three test bacteria in liquid and agar media was comparable to those of three commercial peptones [tryptone peptone (TP), fish peptone and protease peptone (PP)].

CFP was found to be rich in ash (42·1 g 100 g⁻¹), protein (55·8 g 100 g⁻¹) and mineral contents. The maximum biomass yield (3·13 g l⁻¹) and colony number (83 x 10⁸ CFU ml⁻¹ for bacterium Bacillus subtilis were attained with CFP. The maximum biomass yields and colony numbers for Lactobacillus delbrueckii ssp. bulgaricus and Escherichia coli were reached in TP medium. Second high biomass yield (2·64 g l⁻¹) and colony number (75 × 10⁸ CFU ml⁻¹) for E. coli were achieved using CFP. Third high biomass yield (1·29 g l⁻¹) and colony number (90 × 10⁷ CFU ml⁻¹) for Lact. delbrueckii ssp. bulgaricus were obtained in CFP medium.

Usability of waste chicken feathers as substrate for bacteria was investigated for the first time in the present study. The peptone may be used in industrial fermentations for production of antibiotics, organic acids, enzymes and biopolymer. It may be also used in clinical microbiology. A new chemical process was developed for peptone preparation. This process may be also employed for peptone preparation from other organic materials, especially fibrose protein-containing materials.