초록
In these studies concentrated sugar solutions of barley straw and corn stover hydrolysates were fermented using Clostridium beijerinckii P260 with simultaneous product recovery and compared with the performance of a control glucose batch fermentation process. The control glucose batch fermentation resulted in the production of 23.25gL<SUP>-1</SUP> ABE from 55.7gL<SUP>-1</SUP> glucose solution resulting in an ABE productivity and yield of 0.33gL<SUP>-1</SUP>h<SUP>-1</SUP> and 0.42, respectively. The control reactor (I) was started with 62.5gL<SUP>-1</SUP> initial glucose and the culture left 6.8gL<SUP>-1</SUP> unused sugar due to butanol toxicity resulting in incomplete sugar utilization. Barley straw (BS) hydrolysate sugars (90.3gL<SUP>-1</SUP>) resulted in the production of 47.20gL<SUP>-1</SUP> ABE with a productivity of 0.60gL<SUP>-1</SUP>h<SUP>-1</SUP> and a yield of 0.42. Fermentation of corn stover (CS) hydrolysate sugars (93.1gL<SUP>-1</SUP>) produced 50.14gL<SUP>-1</SUP> ABE with a yield of 0.43 and a productivity of 0.70gL<SUP>-1</SUP>h<SUP>-1</SUP>. These productivities are 182-212% higher than the control run. The culture was able to use 99.4-100% sugars (CS & BS respectively) present in these hydrolysates and improve productivities which were possible due to simultaneous product removal. Use of >100gL<SUP>-1</SUP> hydrolysate sugars was not considered as it would have been toxic to the culture in the integrated (simultaneous fermentation and recovery) process.