Revealing the dissimilar structure of microbial communities in different WWTPs that treat fish-canning wastewater with different NaCl content Correa Galeote, David Juárez Jiménez, María José Belén González López, Jesús Juan Rodelas González, María Belén Fish-canning WWTP qPCR Bacterial diversity Halophilic bacteria The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. This research was supported by the Spanish Government (Spanish Ministry of Science and Innovation) through TREASURE-TECHNOSALT (CTQ2017-83225-C2-1-R) and TREASURE-MICROSALT (CTQ2017-83225-C2-2-R) projects. The authors Alba Roibas-Rozas and Anuska Mosquera-Corral belong to the Galician Competitive Research Group GRC-ED431C 2017-29 and to the CRETUS Strategic Partnership (ED431E 2018/01) . All these programmes are co-funded by FEDER (UE) . Funding for open access charge: Universidad de Granada/CBUA. Studies that characterize the microbial communities in wastewater treatment plants (WWTPs) are numerous, yet similar studies in industrial WWTPs treating fish-canning effluents are limited. The microbial communities in samples of 4 fish-canning WWTPs that operated under different NaCl concentrations were investigated by qPCR and partial 16S rRNA gene Illumina sequencing. The absolute abundances of key microbial populations (Total Bacteria, Archaea and Fungi, ammonium oxidizing bacteria (AOB), Mycolata, Candidatus Microthrix, Ca. Accumulibacter and Ca. Competibacter) presented statistical differences among the WWTPs. The NaCl concentration negatively affected the absolute abundance of Bacteria and Fungi, filamentous, and phosphate (PAO) and glycogen (GAO) accumulating bacteria, while AOB and Ca. Microthrix populations were statistically higher in the WWTP with higher NaCl contents. On the other hand, the main bacterial operational taxonomic units (OTUs) were classified as members of Kouleothrix (Chloroflexia, Chloroflexi) and Tetrasphaera (Actinomycetia, Actinobacteria), family Beijerinckiaceae (Alphaproteobacteria, Proteobacteria), order Betaproteobacteriales (Gammaproteobacteria, Proteobacteria), Sphingobacteriales (Sphingobacteriia, Bacteroidetes) and Frankiales (Actinobacteria, Actinobacteria), class Anaerolineae (Chloroflexi), phylum Chloroflexi and Bacteria_unclassified. The structure of the bacterial community was highly dissimilar among the 4 WWTPs, as the identities of the dominant OTUs differed significantly among them. Therefore, the individual characteristics of the different WWTPs, mainly NaCl concentration, were responsible for the narrow assemblage of the bacterial communities. Different OTUs belonging to the phyla Actinobacteria, Bacteroidetes, Chloroflexi, Gemmatimonadetes and Proteobacteria were revealed as salttolerant. Taking into account these results, NaCl content was an important driver of the abundance of microbial populations and the bacterial community structure in the analysed industrial facilities. 2021-11-15T12:23:51Z 2021-11-15T12:23:51Z 2021-10-05 info:eu-repo/semantics/article David Correa-Galeote... [et al.]. Revealing the dissimilar structure of microbial communities in different WWTPs that treat fish-canning wastewater with different NaCl content, Journal of Water Process Engineering, Volume 44, 2021, 102328, ISSN 2214-7144, [https://doi.org/10.1016/j.jwpe.2021.102328] http://hdl.handle.net/10481/71519 10.1016/j.jwpe.2021.102328 eng http://creativecommons.org/licenses/by-nc-nd/3.0/es/ info:eu-repo/semantics/openAccess Atribución-NoComercial-SinDerivadas 3.0 España Elsevier