Chicken feather hydrolysate as alternative peptone source for microbial cultivation [version 3; peer review: 2 approved, 1 not approved]

Background: Commercially available conventional growth media for the culture of microbes are expensive, hence the need for alternative cheaper sources. Livestock waste, in the form of feather and blood, are of value in biotechnology because of their high protein content. Hence the primary aim of this study was to produce a cheaper peptone alternative from chicken feather protein hydrolysate (CFPH) and blood meal (BM). Methods: The growth of selected bacteria and fungi was monitored in different media prepared from varied concentrations of peptone, CFPH and BM in order to determine the combination that produced maximum growth. Five different media, namely 100% peptone (control), 100% BM, 40% peptone + 60% CFPH, 40% BM + 60% CFPH and 20% peptone + 20% BM + 60% CFPH were prepared and used for the study. The different media were inoculated with 1 ml of each test organism ( Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Staphylococcus aureus, Pseudomonas aeruginosa, Candida carpophila, Candida tropicalis and Pichia kundriavzevii) and their growth monitored for 10 h. Results: Pseudomonas aeruginosa, Proteus mirabilis and Staphylococcus aureus grew best in the 100% peptone, Klebsiella pneumoniae grew best in 100 BM. The fungi species were observed to grow best in 100% peptone. The 60% CFPH + 40% peptone combination (CFPH obtained with precipitate of trichloroacetic acid (TCA), hydrochloric acid (HCl) and nitric acid (HNO 3) gave the best growth of E. coli. The 60% CFPH + 40% peptone combination (CFPH obtained with precipitate of TCA) also gave the best growth of C. tropicalis and Klebsiella pneumoniae. Conclusions: Overall, the 60% CFPH + 40% peptone combination showed the most potential as an alternative to peptone, especially for E. coli.