4. Conclusions
A facultative, mesophilic and cellulolytic bacterial strain Caulobacter sp. FMC1 was isolated from lake sediments. Under both aerobic and anaerobic conditions, the strain was capable of inducing exoglucanase, β-1,4-glucosidase, and endoglucanase on cellobiose and cellulose. Meanwhile, ethanol was produced as the main fermentative product under anaerobic cellulose utilization. The competence of aerobic/anaerobic cellulose degradation offered the strain Caulobacter sp. FMC1 with advantages to degrade cellulose in redox-fluctuating environments. Due to its distinct cellulose-degrading ability, this strain also could act as a model to investigate how bacteria tailor cellulose-degrading gene expression under altered redox conditions.
Acknowledgements
This work was supported by grants from the National Natural Science Foundation of China (51079139 and 40971279), and Innovation Program of the Chinese Academy of Sciences (KZCX2-EW-314).