Bioethanol production from cyanobacteria biomass

Abstract

Glycogen is a multibranched polysaccharide with glucose polymer that is main energy storage source in many cyanobacteria. This source is useful for production of bioethanol. We isolated two strains of cyanobacteria as Spirulina maxima and Leptolyngbya sp. including glycogen. The Spirulina maxima was cultured by 10 ton open culture system for 1 year. The biomass was collected with each different time and analysed carbohydrate contents and other environmental conditions. Highest carbohydrate was showed as 56% in total dry biomass. We carried out pre-treatment with different organic solutions at 121℃, 1.5 atm for 30 min and saccharification with spirizyme (Novozymes, Inc.). Reducing suger was analysed by DNS method. Bioethanol was highly produced with the optimum saccharified supernatant. Genome sequence was analysed from Leptolyngbya sp.. Glycogen hydrolysis relative genes were detected from the genome as glycogen debranching enzyme, glycogen phosphorylase and alpha-amylase. The genes were cloned into pET11a and pET16b. Now we are going to study about expression in E. coli. Also, we analysed carbohydrate and monosaccharide contents from the Leptolyngbya sp.. This biomass also may useful for bioethanol production.eptolyngbya sp. including glycogen. The Spirulina maxima was cultured by 10 ton open culture system for 1 year. The biomass was collected with each different time and analysed carbohydrate contents and other environmental conditions. Highest carbohydrate was showed as 56% in total dry biomass. We carried out pre-treatment with different organic solutions at 121℃, 1.5 atm for 30 min and saccharification with spirizyme (Novozymes, Inc.). Reducing suger was analysed by DNS method. Bioethanol was highly produced with the optimum saccharified supernatant. Genome sequence was analysed from Leptolyngbya sp.. Glycogen hydrolysis relative genes were detected from the genome as glycogen debranching enzyme, glycogen phosphorylase and alpha-amylase. The genes were cloned into pET11a and pET16b. Now we are going to study about expression in E. coli. Also, we analysed carbohydrate and monosaccharide contents from the Leptolyngbya sp.. This biomass also may useful for bioethanol production.