A Facultative Electroactive Chromium(VI)-Reducing Bacterium Aerobically Isolated From a Biocathode Microbial Fuel Cell

Frontiers in Microbiology

Xiayuan Wu¹  Xiaoyu Yong¹  Ping Wei¹  Jun Zhou¹  Honghua Jia¹  Xiaoqian Ren²  Gary Owens³  Gianluca Brunetti³ 

[1] Bioenergy Research Institute, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China;College of Chemical Engineering, Nanjing Tech University, Nanjing, China;Environmental Contaminants Group, Future Industries Institute, University of South Australia, Adelaide, SA, Australia;

关键词: Bacillus sp;    microbial fuel cell;    Cr(VI) removal;    biocathode;    electrochemical activity;   

DOI  :  10.3389/fmicb.2018.02883

来源: DOAJ

【 摘 要 】

A facultative electroactive bacterium, designated strain H, was aerobically isolated from the biocathode of a hexavalent chromium (Cr(VI))-reducing microbial fuel cell (MFC). Strain H is Gram-positive and rod shaped (1–3 μm length). 16S rRNA gene analysis suggested that this strain (accession number MH782060) belongs to the genus Bacillus and shows maximum similarity to Bacillus cereus whose electrochemical activity has never previously been reported. Moreover, this strain showed efficient Cr(VI)-reducing ability in both heterotrophic (aerobic LB broth) and autotrophic (anaerobic MFC cathode) environments. Cr(VI) removal reached 50.6 ± 1.8% after 20 h in LB broth supplemented with Cr(VI) (40 mg/L). The strain H biocathode significantly improved the performance of the Cr(VI)-reducing MFC, achieving a maximum power density of 31.80 ± 1.06 mW/m2 and Cr(VI) removal rate of 2.56 ± 0.10 mg/L–h, which were 1.26 and 1.75 times higher than those of the MFC with the sterile control cathode, respectively. This study offers a novel Gram-positive Bacillus sp. strain for Cr(VI) removal in MFCs, and shows a facile aerobic isolation method could be used to screen facultative electroactive bacteria.

【 授权许可】

Unknown