Bifunctional Endoglucanase/Endoxylanase from Cellulomonas flavigena with Potential Use in Industrial Processes at Different pH

• Published in: Current microbiology 2008-07, Vol.57 (1), p.39-44
• Main Authors: Pérez-Avalos, Odilia, Sánchez-Herrera, Leticia M, Salgado, Luis M, Ponce-Noyola, Teresa
• Format: Article
• Language: English
• Subjects: Amino acids; Bacterial Proteins - chemistry; Bacterial Proteins - isolation & purification; Bacterial Proteins - metabolism; Biomedical and Life Sciences; Biotechnology; Cellulase - chemistry; Cellulase - isolation & purification; Cellulase - metabolism; Cellulomonas - chemistry; Cellulomonas - enzymology; Cellulose; Degradation products; Endo-1,4-beta Xylanases - chemistry; Endo-1,4-beta Xylanases - isolation & purification; Endo-1,4-beta Xylanases - metabolism; Enzymes; Hydrogen-Ion Concentration; Industrial Microbiology; Isoelectric Point; Kinetics; Life Sciences; Microbiology; Molecular Weight; Sequence Analysis, Protein
• ISSN: 0343-8651; 1432-0991
• DOI: 10.1007/s00284-008-9149-1

Cellulomonas flavigena CDBB-531 was found to secrete a bifunctional cellulase/xylanase with a molecular mass of 49 kDa and pI 4.3. This enzyme was active on Remazol brilliant blue-carboxymethylcellulose (RBB-CMC) and Remazol brilliant blue-xylan (RBB-X). Based on thin-layer chromatographic analysis of the degradation products, the cellulase activity produced glucose, cellobiose, cellotriose, and cellotetraose from CMC as the substrate. When xylan from birchwood was used, end products were xylose, arabinose, and xylobiose. The bifunctional enzyme showed a pH optimum of 6 for cellulase activity and 9 for xylanase activity, which pointed out that this enzyme had separate sites for each activity. In both cases, the apparent optimum temperature was 50°C. The predicted amino acid sequence of purified protein showed similarity with the catalytic domain of several glycosyl hydrolases of family 10.