Abstract: The present application concerns a thermostable chitosanase, originally identified in Paenibacillus sp., having an optimal temperature of about 80° C. when measured at a reaction time of about 10 minutes. Also contemplated are variants of this chitosanase (sharing more than 81% identity) as well as fragments thereof. The present application further concerns nucleic acid molecules encoding the chitosanase, vector comprising them as well as host cell expressing them. Methods of producing the thermostable chitosanase as well as using it for generating low molecular weight chitosan and chitosan oligosaccharides are also disclosed.