Xylanases from thermophilic archaea: A hidden treasure

Archaea are a domain of prokaryotic organisms that often inhabit extremophilic environments. Their enzymes therefore enormous biotechnological interest, due to their stability and activity in harsh conditions. Although bioprospection by the metagenomics extreme environments has yielded many novel xylanases (endo-xylanases β-xylosidades), most show highest sequence similarity bacteria or unculturable microorganisms not archaea. This graphical review focuses on very promising but underexploited (hyper)thermophilic archaeal xylanases. There only few examples isolated from culturable So far, 5 different strains with xylanase have been described, which 4 present endo-xylanase one shows both β-xylosidase activity. All them enzymatic under high optimum temperature, neutral pH (with exception). These facts, together important applications xylanases, reveal be hidden treasure biotechnology. Bioprospection endo-xylanases constitutes relatively unexploited field, full potential.