At present, most technologies utilise fungal enzymes in the production of fermentable sugars. However, current enzyme hydrolysis processes cannot be considered to be optimal due to inherent enzymatic deficiencies, such as moderate Opt. Temp (~40°C-50°C), and very short half-lives at higher temperatures (eg. 70 °C) for most fungal enzymes [Ref 1].
We present here an effective two-stage enzyme hydrolysis method for the production of high levels of fermentable sugars. A mixture of fungal hydrolytic enzymes from a Trichoderma reesei recombinant strain that also produced and secreted a thermophilic xylanase was used. 1.34-fold and 18.47-fold more glucose and xylose, respectively, were produced from P. radiata sawdust following two-stage hydrolysis at 50°C and 70°C. Similarly, a 38% increase in total reducing sugar release was generated only after using (1), a cocktail of T. reesei’s own hydrolytic enzymes with thermophilic bacterial cellulases, mannanase, xylanases/xylosidase and a glucosidase were incubated with P. radiata kraft pulp, and (2) a 50°C / 70°C two-stage hydrolysis method.
We will also outline a step-by-step procedure on how to generate thermophilic bacterial hydrolytic enzymes (eg. xylanasaes, cellulases, etc) for scale-up production using a high secreting fungal system.