Evaluation of electricity production from paper industry wastewater by Cellulomonas iranensis LZ-P1 isolated from giant panda

Microbial fuel cell (MFC) is considered to be a sustainable technology for cellulosic waste treatment and energy recovery; however, studies on cellulose-degrading exoelectrogens are scarce. Giant panda gut microbiota may provide potential cellulose-degrading exoelectrogens due to consumption of high-fiber diet. In this study, strain LZ-P1 isolated from giant panda gut simultaneously showed cellulose-degrading and electricity-generating characteristics. 16S rRNA gene sequence revealed 99% homology with Cellulomonas iranensis. Results showed that the strain generated 1.08 U/mL endoglucanase and 180 mV electricity when cellulose was used as the sole carbon source. Genome sequence confirmed that strain LZ-P1 possessed complete cellulose degradation and extracellular electron transfer pathways. Proteomic analysis further confirmed that the enzymes involved in cellulose-degradation and extracellular electron transport were remarkably up-regulated, including endoglucanases, riboflavin biosynthesis protein, and cytochrome C oxidase. When strain LZ-P1 was applied to MFC-mediated paper recycling wastewater treatment, a maximum power density of 44.05 mW/m(2) and 8.72% coulombic efficiency were recovered in 72 h. Therefore, strain LZ-P1 would be a potential candidate for cellulosic waste management and energy recovery. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

Microbial fuel cell (MFC) represents a sustainable technology for cellulosic waste treatment and energy recovery. A strain LZ-P1 isolated from giant panda gut showed cellulose-degrading and electricity-generating characteristics, with potential for paper recycling wastewater treatment. Proteomic analysis revealed up-regulation of enzymes involved in cellulose-degradation and extracellular electron transport, confirming the strain's potential for cellulosic waste management and energy recovery.