earticle

영어

For sustainable development of current industries, many research groups have made an effort to change the currently available crude oil to the renewable biomass as resources. To overcome the general problems of corn- and sugar-based biomass, non-food biomass such as cellulosic and marine biomass has been concerned as alternative biomass for production of biofuels and biochemicals. Contrary to cellulosic biomass (tree, straw, agricultural residue et al.), marine biomass (red, green, brown algae) does not contain lignin, of which presence raises many problems in bioprocess for biomaterial production. Among marine biomass, red algae are mostly composed of cellulose and galactan. Galactan is a representative polymer consisting of D-galactose and anhydro-galactose. For efficient conversion of red algae to biomaterials, both glucose from cellulose and D-galactose from galactan should be fermented. In this study, a food-grade lactic acid bacterium, Lactobacillus casei was chosen to be metabolically engineered to produce a value-added biochemical of lactic acid and a promising biofuel of bioethanol simultaneously from both glucose and galactose. For simultaneous production of lactic acid and bioethanol, two foreign genes coding for pyruvate decarboxylase and alcohol dehydrogenase were expressed and many genes encoding endogenous lactate dehydrogenase were disrupted in Lactobacillus strains. Batch fermentation and transcriptional analysis were undertaken to investigate the simultaneous production of lactic acid and bioethanol. In this research, it is provided that red algae and lactic acid bacteria have a potential to be used for production of biofuels and biochemcials.