Microbial diversity of anodic biofilm in bioelectrochemical systems with hemp rod carbonized at 1000 and 1800℃ as anode was investigated using Solexa high-throughput sequencing technology. The results showed that a total of 4231 and 5263 optimized 16S rRNA gene sequences were gained from the electrode biofilm on the hemp rod carbonized at 1000 and 1800℃, respectively. At the level of 97% similarity, 1187 and 1338 OTUs were obtained for electrode biofilm carbonized at 1000 and 1800℃, respectively. The result of α diversity analysis showed that microbial diversity increased with decreasing carbonization temperature. Dominant phylum for both biofilms were Proteobacteria, Firmicutes and Bacteroidetes, which accounted for 66%, 10% and 9%, respectively for 1000℃, while 71%, 7% and 9%, respectively for 1800℃. Beside the coexisting phylum, some unique species were also discovered, demonstrating that carbonization temperature did not only influence the electrode structure, but also affected the microbial community structure.
Keywords: bioelectrochemical system; carbonization temperature; hemp rod; high-throughput sequencing; microbial community structure.