earticle

영어

During hydrolysis of lignocellulosic biomass, monomeric sugars and a broad range of inhibitory compounds are formed and released. These inhibitors, which can be organized around three main groups, furans, weak acids and phenolics, reduce ethanol yield and productivity by affecting the microorganism performance. Among them, furfural and hydroxy-methylfurfural(HMF) are considered to be the most toxic inhibitors present in lignocellulosic hydrolysates,. The inhibitor mixtures synergistically inhibit the ethanol fermentation by yeast. In this work, we have screened for the highest ethanol production and inhibitor resistance and selected Saccharomyces cerevisiae KL5. The KL5 strain was treated with UV, γ-irradiation, N-methyl-N-nitro-N-nitrosoguanidine at the dosage for 10% survival. Improved inhibitor resistant colonies were isolated and the colonies were adapted to inhibitor cocktail by repeatedly transferring the cells to higher concentration of inhibitors. The cells could grow at 33℃ in minimal medium with 80% inhibitor cocktail while the original strain could not grow. Also KL5 mutant strain produced more ethanol than original control at 33℃ in a minimal medium containing 60% inhibitor cocktail by up to 82 ~ 95%.