| 高温厌氧细菌混合培养对纤维素酒精生产的提高作用 |
| 摘要点击 1753 全文点击 2151 修订日期：2009-08-04 |
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| 中文关键词 纤维素酒精 高温厌氧菌 混合培养 生物能源 酒精发酵 |
| 英文关键词 cellulosic ethanol thermophilic anaerobic bacteria co-culture bioenergy ethanol fermentation |
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| 中文摘要 |
| 以高温厌氧细菌热纤维梭菌 (clostridium thermocellum LQRI) 和嗜热厌氧乙醇菌 (Thermoanaerobacter ethanolicus X514和Thermoanaerobacter pseudoethanolicus 39E) 为对象，以纤维素为微生物利用的底物，分析了LQRI纯培养和LQRI+Thermoanaerobacter混合培养对纤维素降解、酒精生产及终产物分布的影响.结果表明，LQRI+Thermoanaerobacter混合培养的酒精生产能力和纤维素降解率明显高于LQRI纯培养.在混合培养体系中，LQRI+X514的酒精生产能力明显高于LQRI+39E.培养基中无外源酵母粉条件下，LQRI纯培养酒精最高浓度约为11.5 mmol/L， LQRI+X514和LQRI+39E混合培养最高酒精浓度分别约为71 mmol/L和36.5 mmol/L，相同的底物纤维素浓度条件LQRI+X514和LQRI+39E混合培养酒精浓度分别约为LQRI纯培养的5～11倍和3～5倍，纤维素降解率分别都约为LQRI纯培养的1.5～5.0倍；培养基中0.6％外源酵母粉存在条件下，LQRI纯培养酒精最高浓度约为12.9 mmol/L， LQRI+X514和LQRI+39E混合培养最高酒精浓度分别约为263.5 mmol/L和143.5 mmol/L，相同的底物纤维素浓度条件LQRI+X514和LQRI+39E混合培养酒精浓度分别约为LQRI纯培养的8～22倍和8～12倍，纤维素降解率均约为LQRI纯培养的1.1倍.在5％Solka Floc为底物和0.6％外源酵母粉的条件下，LQRI+X514混合培养酒精浓度最高可达到263.5 mmol/L，相当于1.2% (质量浓度)的酒精，LQRI＋39E约为143 mmol/L. |
| 英文摘要 |
| Fermentation of the type of cellulosic materials to ethanol was evaluated in batch system of mono-cultures of cellulolytic ethanol producing strains (clostridium thermocellum strain LQRI)， and co-cultures of LQRI in combination with one of the non-cellulolytic ethanol producing strains (Thermoanaerobacter pseudoethanolicus strains X514 or Thermoanaerobacter ethanolicus 39E). Results showed that ethanol yields and cellulose degradation abilities were significantly improved by the establishment of co-cultures consisting of LQRI and Thermoanaerobacter ethanolicus partner. A factorial experimental comparison revealed that the co-culture of LQRI+X514 provided the higher ethanol yield than the co-culture of LQRI+39E， but no significant difference on cellulose degradation by LQRI was found in these co-cultures. In the absence of yeast extract， the highest ethanol concentrations in the co-cultures of LQRI+X514 and LQRI+39E were about 71 mmol/L and 36.5 mmol/L， which were approximately 5-11 and 3-5 times higher than that of the mono-culture LQRI under the same concentration substrate， respectively. In the presence of 0.6% yeast extract， the highest ethanol concentrations in the co-cultures of LQRI+X514 and LQRI+39E were rapidly improved and reached 263.5 mmol/L and 143.5 mmol/L， which were approximately 8-22 and 8-12 times higher than that of the mono-culture LQRI under the same concentrations substrate， respectively. The maximum ethanol concentration reached about 263.5 mmol/L (1.2%) in the co-culture of LQRI+X514 grown on 5% Solka Floc in the presence of 0.6% yeast extract， while the maximum ethanol concentration reached 143.5 mmol/L (1.2%) in the co-culture of LQRI+39E grown on 2% Solka Floc in the presence of 0.6% yeast extract. |
