Ak. Shah et al., Treatment of bagasse pulp with cellulase-free xylanases from an alkalophilic Bacillus sp. Sam-3, BIORES TECH, 68(2), 1999, pp. 133-140
An alkalophilic Bacillus sp Sam-3, producing high levels of cellulase-free
xylanase active and stable at alkaline pH was isolated from a soda lake. Wh
en grown in shake flasks for 48 h on agricultural residues such as wheat br
an supplemented with yeast extract, the culture produced 131 IU ml(-1) enzy
me activity. The optimum pH and temperature of the enzyme were 8 and 60 deg
rees C, respectively. The enzyme retained approximately 75% of its activity
at pH 8 and 60 degrees C when incubated for 2 h. Enzymatic treatment of ba
gasse pulp carried out using 1.2 IU of enzyme per gram of pulp at 60 degree
s C and pH 8 for 2 h resulted in a 4 unit decrease in the kappa number. Sim
ilar treatment of the pulp at pH 7 and 9 indicated that the Sam-3 xylanase
was effective in reducing the kappa number of the pulp over a wide pH range
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