Ethanol production from lignocelluloses by native strain Klebsiella oxytoca THLC0409

The native strain Klebsiella oxytoca THLC0409 was isolated from a lignocelluloses-degrading microflora. Preliminary investigations were conducted to obtain the optimal growth conditions of the strain. Batch operations were applied for producing ethanol from various lignocelluloses via direct microbial conversion (DMC). The strain THLC0409 was a naturally-occurring cellulolytic microorganism having high capability of utilizing celluloses (avicel, α-cellulose) and natural lignocelluloses (corncob, Napiergrass, purified bamboo, raw bamboo, rice straw). However, THLC0409 is an enteric bacterium lacking cellulase and xylanase activity. The ethanol productions varied depending on the compositions of substrate lignocelluloses. Under the optimal conditions, ethanol yields on corncob and Napiergrass reached 0.0623 and 0.0475 g g ^-1, respectively, which were far higher than those on avicel (0.019 g g ^-1), α-cellulose (0.02 g g ^-1), purified bamboo (0.02 g g ^-1), raw bamboo (0.018 g g ^-1), and rice straw (0.016 g g ^-1). Moreover, ethanol yields on oat-extracted xylan and corncob-extracted xylan were 0.15 and 0.04 g g ^-1, respectively.