Aims:  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. Methods and Results:  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)]. Conclusions:  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 × 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. Significance and Impact of the Study:  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.

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Deproteinized whey was used as a substrate for the production of lipids by cold‐adapted yeast Yarrowia lipolytica B9 under non‐sterile culture conditions. Undesired microbial contamination in non‐sterile whey medium could be prevented when appropriate culture parameters (inoculum size of 3 mL/100 mL, initial pH of 5.5 and incubation temperature of 15 °C) were selected. In contrast to additional nitrogen (ammonium sulfate) and phosphorus (potassium dihydrogen phosphate) sources, additional carbon source (lactose) increased lipid accumulation. Under optimized culture conditions, biomass and lipid concentrations of the yeast were found as 7.4 g/L and 4.29 g/L, respectively. Lipid content was determined as 58% of total cell biomass. Fatty acids of the yeast were oleic acid (18:1), cis‐10‐heptadecenoic acid (C17:1), palmitoleic acid (16:1) and palmitic acid (16:0). The yeast was found to contain no polyunsaturated fatty acids. The content of C16 and C18 fatty acids was found to be 91.98% of total lipids. Monounsaturated fatty acids accounted for 80.54% of total lipids. Due to rich monounsaturated fatty acid composition, biomass of Y. lipolytica B9 may be used as feedstock for biodiesel production, especially operating in winter conditions. This is the first report on the use of cheese whey as a lipid production substrate for cold‐adapted microorganisms including Y. lipolytica yeast. Besides, lipid production potential of Y. lipolytica under non‐sterile culture conditions was investigated for the first time in this study. © 2015 Society of Chemical Industry and John Wiley & Sons, Ltd

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