Enhancing the anti-biofilm activity of novel keratinase isolated from Acinetobacter baumannii using Reduced Graphene oxide: A way to recycle feather waste pollution

Poultry feathers are rich with keratin protein and so represent environmental pollutant due to contamination with different microbes. The goal of this study is to recycle feather wastes and decrease pollutants using graphene-based material mixed with keratinase enzyme, which is purified from bacteria isolated from slaughterhouses. Fifteen isolates of Acinetobacter baumannii (A. baumannii) out of 100 swabs were collected from different slaughterhouses. The keratinase activity of these isolates was measured. Nine isolates produced keratinase and the keratinase activity of these isolates reaches primer filter up to 44 U/mL. A purified enzyme was obtained from these isolates. Reduced Graphene oxide (rGO) solution was mixed with keratinase. The resulting nanomaterial was characterized in vitro, and the anti-biofilm activity was screened. The effect of keratinase/rGO on the expression of biofilm-related genes (bap, blaPER-1 gene, ompA, and csuE genes) in A. baumannii was evaluated using RT-PCR. The expression of biofilm-related genes was down regulated after adding the rGO exposure to Keratinase/rGO. In conclusion, Keratinase-loaded reduced Graphene oxide have potential anti-biofilm activity and may be used to recycle feather waste pollution.