Co-operative Actions between Xylanases from Bacillus firmus K-1 and Bacillus halodurans C-1 on Xylan Hydrolysis and Chromophores Release from Kraft Pulps

Abstract

The crude xylanases were produced from Bacillus halodurans C-1 and Bacillus firmus K-1grown in the non sterile medium containing 1% corn hull as a sole source of carbon and 0.4% ureaas a sole source of nitrogen under alkaline condition. The optimization of the combination of thesecrude enzymes for hydrolysis of xylan and chromophores release from kraft pulps of eucalyptus,bagasse and pine was conducted. It was found that the best ratios of crude xylanases from Bacillushalodurans C-1 and Bacillus firmus K-1 were 1 : 9 for eucalyptus and bagasse pulps and 3 : 7 for pinepulp. The results also showed that the release of reducing sugars from the 3 pulps were related to therelease of chromophores.

Keywords : Bacillus firmus K-1 / Bacillus halodurans C-1 / Chromophores / Co-operativeActions between Xylanases / Hydrolysis of Xylan / Kraft Pulp