Purification and characterization of a thermostable-cellulase free xylanase from Syncephalastrum racemosum Cohn

Meenaksui P. Sapre, Harit Jha, Mandakini B. Patil
2005 Journal of General and Applied Microbiology  
Syncephalastrum racemosum Cohn. produces an extracellular xylanase that was shown to potentially bleach pulp at pH 10 and 50°C. The enzyme was found to be a dimer with an apparent molecular weight of 29 kDa as determined by SDS-PAGE. The optimum activity was found at two pH values 8.5 and 10.5; however the activity sharply decreased below pH 6 and above pH 10.5. The enzyme was stable for 72 h at pH 10.5 and at 50°C. Kinetic experiments at 50°C gave V max and K m of 1,400 U/ml min ؊1 mg ؊1
more » ... n and 0.05 mg/ml respectively. The enzyme had no apparent requirement for cofactors, and its activity was strongly inhibited by group II b metal ions like Zn 2؉ , Hg 2؉ , etc. Xylan completely protected the enzyme from being inactivated by N-bromosuccinimide.
doi:10.2323/jgam.51.327 pmid:16474192 fatcat:ss57ckz23nfjfdlp2jjjojb32u