Characterisation of the glycoside hydrolase domain of a novel bi-functional metagenomic clone for use in the biofuel production industry

[摘要] ENGLISH ABSTRACT: The current practice of 1st generation biofuel production is marred by several hurdles, namely concernsover food security and the moral dilemma created by using edible feedstocks as a biofuel productionsource. Second generation biofuel production methods stand to take the forefront and address theworld's need for a renewable liquid fuel source without affecting food security and adding value to theabundant lignocellulosic biomass available worldwide. However, in order to achieve this, 2nd generationbiofuel production methods need to become more efficient at liberating fermentable glucose fromlignocellulosic biomass. Metagenomic sampling and novel enzyme discovery are the most promisingsources of finding new, more efficient enzymes from unculturable microorganisms that can degradelignocellulosic biomass into fermentable glucose more ably than current enzymes used in industry.Industrial enzymes within the biofuels scope are required to be thermotolerant, pH tolerant, resistant toproduct inhibition and resistant to denaturation by industrial solvents. A novel, bi-functional, ßglucosidaseand ß-galactosidase enzyme, termed Clone 3L, was identified via a metagenomic samplingapproach. This study outlines the characterization of clone 3L, including the kinetics of the enzyme andan assessment of the suitability of the enzyme within an industrial, 2nd generation biofuel productionpipeline. Clone 3L was found to be a promising candidate for use in 2nd generation biofuel productionschemes, with the enzyme exhibiting high activity and affinity for its cellobiose substrate and a highdegree of tolerance to various solvents, glucose inhibition and a high activity across a wide pH range.

[发布机构] Stellenbosch University