Heterologous expression and characterization of a novel lytic polysaccharide monooxygenase from Natrialbaceae archaeon and its application for chitin biodegradation

•NaLPMO10A is the first archaeal LPMO to be studied.•NaLPMO10A with two CBM5/12 domains is a C1- oxidizing chitin-active LPMO.•NaLPMO10A displays high thermostability.•NaLPMO10A shows great tolerance and stability against high concentration of metal ions.•NaLPMO10A can significantly improve the chitin degradation under extreme osmolytic condition.