Saccharification of Arthrospira maxima glycogen by fungal amylolytic enzyme complex from Trichoderma species J113

Abstract

There is a pressing need to reduce our dependency on fossil fuels with alternative carbon-neutral fuels from renewable bioresources. Cyanobacteria have garnered increased interest as the biomass of choice for renewable energy production, as well as cyanobacteria have advantageous characteristics for biofuel production when compared to conventional agricultural crops. Cyanobacteria primarily store glycogen as the carbohydrate reserve, with certain strains reaching upto 50% glycogen as its biomass under favorable growth conditions. For effective saccharifcation of cyanobacteria, developments of high-yield and low cost amylases are needed. In this study, we isolated a new Trichoderma species J113 strain from the coastal terrains of Korea for its high amylolytic enzyme activity. Fungal crude extract was subsequently purified through filtrations, precipitation, and chromatography. J113 enzyme complex consists of two major amylases, Ayt40 and Ayt70, that were determined as an α-amylase and a gluco-amylase, respectively. Two amylases exhibited different pH and temperature requirements for optimum performance, but collectively the enzyme complex showed the highest activity at pH 4 and 60°C. In addition, Ayt70 amylolytic capacity was drastically enhanced by 291% with 5 mM Mn2+ amendment. Significantly, J113 enzyme complex converted 20 g/L of Arthrospira maxima to 7.81 g/L of reducing sugar with Mn2+ compared to only 4.09 well as cyanobacteria have advantageous characteristics for biofuel production when compared to conventional agricultural crops. Cyanobacteria primarily store glycogen as the carbohydrate reserve, with certain strains reaching upto 50% glycogen as its biomass under favorable growth conditions. For effective saccharifcation of cyanobacteria, developments of high-yield and low cost amylases are needed. In this study, we isolated a new Trichoderma species J113 strain from the coastal terrains of Korea for its high amylolytic enzyme activity. Fungal crude extract was subsequently purified through filtrations, precipitation, and chromatography. J113 enzyme complex consists of two major amylases, Ayt40 and Ayt70, that were determined as an α-amylase and a gluco-amylase, respectively. Two amylases exhibited different pH and temperature requirements for optimum performance, but collectively the enzyme complex showed the highest activity at pH 4 and 60°C. In addition, Ayt70 amylolytic capacity was drastically enhanced by 291% with 5 mM Mn2+ amendment. Significantly, J113 enzyme complex converted 20 g/L of Arthrospira maxima to 7.81 g/L of reducing sugar with Mn2+ compared to only 4.09