Addition of beta-galactosidase boosts the xyloglucan degradation capability of endoglucanase Cel9D from Clostridium thermocellum

作者：Herlet Jonathan; Schwarz Wolfgang H; Zverlov Vladimir V; Liebl Wolfgang^*; Kornberger Petra

来源：Biotechnology for Biofuels, 2018, 11(1): 238.

DOI：10.1186/s13068-018-1242-5

• Xyloglucan (XG)
• beta-Galactosidase
• Endoglucanase
• Enzyme synergism
• Tamarind kernel powder (TKP)
• Biomass degradation

Background: Increasing the efficiency of enzymatic biomass degradation is crucial for a more economically feasible conversion of abundantly available plant feedstock. Synergistic effects between the enzymes deployed in the hydrolysis of various hemicelluloses have been demonstrated, which can reduce process costs by lowering the amount of enzyme required for the reaction. Xyloglucan is the only major hemicellulose for which no such effects have been described yet.
Results: We report the beneficial combination of two enzymes for the degradation of the hemicellulose xyloglucan. The addition of beta-galactosidase Bga2B from Clostridium stercorarium to an in vitro hydrolysis reaction of a model xyloglucan substrate increased the enzymatic efficiency of endoglucanase Cel9D from Clostridium thermocellum to up to 22-fold. Furthermore, the total amount of enzyme required for high hydrolysis yields was lowered by nearly 80%. Increased yields were also observed when using a natural complex substrate-tamarind kernel powder.
Conclusion: The findings of this study may improve the valorization of feedstocks containing high-xyloglucan amounts. The combination of the endoglucanase Cel9D and the beta-galactosidase Bga2B can be used to efficiently produce the heptasaccharide XXXG. The exploitation of one specific oligosaccharide may open up possibilities for the use as a prebiotic or platform chemical in additional reactions.

• 出版日期2018-9-4