The hyperthermophilic xylanase B (XynB) from Thermotoga maritima expressed in E. coli has expert alkaline-tolerant and thermostability, even under the conditions of 100℃ and pH 6.5~8.5. Hence, hyperthermophilic xylanase B is a promising xylanase applied in pre-bleaching and oligo-xylo-saccharides production.
The hyperthermophilic xylanase B, which came from Thermotoga maritima MSB8 and was expressed in Pichia pastoris , was modified by NBS, DTNB, Phenylgloxal, PMSF and WRK.
When the feed velocity of methanol was 3mL/(h.L), the OD600 of Pichia pastoris reached to 260 after 10 days, and the xylanase activity was 108 U/mL, the protein was 207mg/L.
A thermostable xylanase purified from a strain of Bacillus amyloliquefaciens MIR 32 was characterized with respect to its substrate specificity and mode of hydrolytic action.
The hyperthermophilic archaeon Pyrodictium abyssi, which was originally isolated from marine hot abyssal sites, grows optimally at 97°C and is a prospective source of highly thermostable xylanase.