GLYCOGEN HYDROLYSIS OF CYANOBACTERIA BY FUNGAL AMYLOLYTIC ENZYME COMPLEX FOR BIOETHANOL PRODUCTION

Abstract

Photosynthetic microorganisms have garnered increased interest as the biomass of choice for renewable energy production. These organisms, namely microalgae and cyanobacteria, have advantageous characteristics for biofuel production when compared to conventional agricultural crops. First and foremost, the use of microorganism biomass for fuel production does not negatively impact food and feed. Also, these microorganisms have much higher net energy balance (NEB) and require significantly less arable land, if any, for more efficient mass cultivation than 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 and determined that the fungus has a high amylolytic enzyme activity. We cultured the fungus on wheat bran to stimulate enzyme production, and the crude extract was subsequently purified through filtrations, precipitation, and chromatography. We learned that J113 enzyme complex consists of two major amylases, Ayt40 and Ayt70, that were determined as an endo-amylase and an exo-amylase, respectively. While these two amylases exhibited different pH and temperature requirements for optpared to conventional agricultural crops. First and foremost, the use of microorganism biomass for fuel production does not negatively impact food and feed. Also, these microorganisms have much higher net energy balance (NEB) and require significantly less arable land, if any, for more efficient mass cultivation than 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 and determined that the fungus has a high amylolytic enzyme activity. We cultured the fungus on wheat bran to stimulate enzyme production, and the crude extract was subsequently purified through filtrations, precipitation, and chromatography. We learned that J113 enzyme complex consists of two major amylases, Ayt40 and Ayt70, that were determined as an endo-amylase and an exo-amylase, respectively. While these two amylases exhibited different pH and temperature requirements for opt