Aims: The objective of this study was to design an economically feasible process for endoglucanase (EG) production.
Methods and results: Trichoderma pseudokoingii S-38 EG synthesis was studied. Initially, either glucose at 2.5, 5 or 10 g l-1, or cellulose powder (CF11) at 5 g l-1 was used as the sole carbon source. The results showed that enzyme synthesis and biomass formation were closely correlated, and both were affected by the carbon source. To improve EG volumetric product efficiency, a new technique was developed. Glucose and CF11 (2.5 and 5 g l-1, respectively) were used as initial carbon source, and glucose was added at 2.5 g l-1 day-1. EG activity, volumetric and specific EG productivities were 6.17 IU l-1, 53 IU l-1 h-1 and 114.3 IU (g cell protein)-1 h-1, respectively. Batch production in a 2-l laboratory fermenter confirmed the advantage of the technique. The product contained 10.86 IU ml-1 EG activity in 88 h. The volumetric and specific EG productivities were 123.4 IU l-1 h-1 and 177.8 IU (g cell protein)-1 h-1, respectively.
Conclusions: These results suggest that optimization of the ratio of glucose to CF11 for balancing the induction and growth rate in the production of EG may lead to technical and economical benefits.
Significance and impact of the study: A new technique was developed for the production of EG which improves both the volumetric product efficiency and the specific activity.