earticle

영어

Recently, there has been a growing interest in the second generation biofuels made from not starch and sugar-based biomass but lignocellulose-containing biomass. The physical and/or
chemical pretreatment followed by enzymatic hydrolysis has been most widely used to convert
lignocellulosic materials to fermentable sugars, mainly including glucose, xylose, and arabinose. In this study, Clostridium acetobutylicum ATCC824 and Clostridium beijerinckii
ATCC35702 were cultivated in the media, containing various contents of citrate that is commonly added to the pretreated biomass in order to maintain the pH during enzymatic hydrolysis. C. acetobutylicum ATCC824 growth was inhibited in the presence of 1 to 5 g/L citrate and the lag time was more than twice as long as that of the control. The butanol production was also decreased by about 20%. On the other hand, no inhibitory effects of citrate below 5 g/L on the growth of C. beijerinckii ATCC35702 and the production of butanol have been observed. Although the butanol production and cell growth rates were decreased in the 10 g/L of citrate, the maximum butanol titer was not much different from that of the control. The threshold values of citrate for butanol production without taking a consideration of butanol concentration and production rate are 5 g/L and 10 g/L for C. acetobutylicum ATCC824 and C. beijerinckii ATCC35702, respectively. When it comes to the butanol production rate, however, citrate should be maintained less 1 g/L for C. acetobutylicum ATCC824 and 5g/L for C. beijerinckii ATCC35702.This work was financially supported by Energy Technology Innovation (ETI) Program of the Korean Ministry of Knowledge Economy (MKE).