Interconnection of Waste Chicken Feather Biodegradation and Keratinase and mcl-PHA Production Employing Pseudomonas putida KT2440

Abstract

Background and objective: Waste chicken feather is an important waste product of the poultry processing industry and is annually produced in substantial amounts. Hence, wise management of this waste is desirable. In this work we aimed at feathers biodegradation by a selected bacterial strain capable of utilizing chicken feathers as sole carbon source Pseudomonas putida KT2440. To utilize feather, the bacterial culture excrete keratinase, which can be easily isolated after biodegradation process and which, therefore, represents an interesting side product of the intended technology. Moreover, bacterial culture of employed for feather degradation is also capable of mcl-PHA accumulation. Materials and methods: Bacterial culture of Pseudomonas putida KT2440 was cultivated in presence of waste chicken feathers as the only carbon source; during the cultivation keratinase activity and biomass growth were monitored. Metabolically active biomass after feather degradation was used for mcl-PHA production. Results and conclusion: During cultivation on waste feathers, bacteria did not accumulate detectable amounts of medium-chain length polyhydroxyalkanoate (mcl-PHA); nevertheless, when metabolically active bacterial cells after feather biodegradation were transferred into nitrogen limited mineral media, a high medium-chain length polyhydroxyalkanoate content of 61% of cell dry weight in microbial cells was reached. The polymer consisted of 3- hydroxyhexanoate (27.2% mol) and 3-hydroxyoctanoate (72.8% mol) monomer units. Therefore, this work demonstrates a possible interconnection of feather biodegradation with keratinase and medium-chain length polyhydroxyalkanoate production. Conflict of interest: The authors declare no conflict of interest.

Keywords

• ▪ Waste feathers ▪ Pseudomonas putida ▪ keratinase ▪ mcl-PHA