title: Symbiotic relationship analysis of predominant bacteria in a lab-scale anammox UASB bioreactor.
abstract: In order to provide the comprehensive insight into the key microbial groups in anaerobic ammonium oxidation (anammox) process, high-throughput sequencing analysis has been used for the investigation of the bacterial communities of a lab-scale upflow anaerobic sludge bed (UASB) anammox bioreactor. Results revealed that 109 operational taxonomic units (OTUs; out of 14,820 reads) were identified and a domination of anammox bacteria of Candidatus Kuenenia stuttgartiensis (OTU474, 35.42 %), along with heterotrophs of Limnobacter sp. MED105 (OTU951, 14.98 %), Anerolinea thermophila UNI-1 (OTU465 and OTU833, 6.60 and 3.93 %), Azoarcus sp. B72 (OTU26, 9.47 %), and Ignavibacterium sp. JCM 16511 (OTU459, 8.33 %) were detected. Metabolic pathway analysis showed that Candidatus K. stuttgartiensis encountered gene defect in synthesizing a series of metabolic cofactors for growth, implying that K. stuttgartiensis is auxotrophic. Coincidentally, the other dominant species severally showed complete metabolic pathways with full set gene encoding to corresponding cofactors presented in the surrounding environment. Furthermore, it was likely that the survival of heterotrophs in the autotrophic system indicates the existence of a symbiotic and mutual relationship in anammox system.
authors.affiliation: College of Resources and Civil Engineering, Northeastern University, Shenyang, 110819, People's Republic of China.
authors.forename: Yujia
authors.initials: Y
authors.lastname: Wang
authors.affiliation: College of Resources and Civil Engineering, Northeastern University, Shenyang, 110819, People's Republic of China. hxmin_jj@163.com.
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Hu
authors.affiliation: College of Resources and Civil Engineering, Northeastern University, Shenyang, 110819, People's Republic of China.
authors.forename: Binhui
authors.initials: B
authors.lastname: Jiang
authors.affiliation: College of Resources and Civil Engineering, Northeastern University, Shenyang, 110819, People's Republic of China.
authors.forename: Zhenhui
authors.initials: Z
authors.lastname: Song
authors.affiliation: Process Equipment and Environmental Engineering Institute, Northeastern University, Shenyang, 110819, People's Republic of China.
authors.forename: Yongguang
authors.initials: Y
authors.lastname: Ma
mesh_terms: D000641:Ammonia / Q000737:chemistry / Q000378:metabolism; D001419:Bacteria; D019149:Bioreactors / Q000382:microbiology*; D012722:Sewage; D013559:Symbiosis
chemical_list: D012722:Sewage; D000641:Ammonia
keywords: Anammox; Cofactor deficiency; High-throughput sequencing; Kyoto Encyclopedia for Genes and Genomes (KEGG); Metabolic pathway analysis; Nitrogen removal; Symbiosis