PRJDB3078 Community composition of known and uncultured archaeal lineages in anaerobic wastewater treatment sludge It has long been thought that Archaea play a crucial role in biological wastewater treatment systems. In order to investigate known and uncultured archaeal community composition existed in anaerobic wastewater treatment sludges, we performed 16S rRNA gene sequencing by using Archaea-specific primer set. Phylotypes belonging to phylum Euryarchaeota were the most predominant in methanogenic, denitrifying and nitrogen-/phosphate-removing wastewater treatment sludge. Besides, Deep Sea Hydrothermal Vent Group 6 (DHVEG-6), Terrestrial Miscellaneous Euryarchaeotal Group, WSA2 and Miscellaneous Crenarchaeotic Group were detected in each sludge sample. This project can provide a archaeal diversity in various sludges. Community composition of known and uncultured archaeal lineages in anaerobic wastewater treatment sludge bioproject PRJDB3078 PRJDB3078 true It has long been thought that Archaea play a crucial role in biological wastewater treatment systems. In order to investigate known and uncultured archaeal community composition existed in anaerobic wastewater treatment sludges, we performed 16S rRNA gene sequencing by using Archaea-specific primer set. Phylotypes belonging to phylum Euryarchaeota were the most predominant in methanogenic, denitrifying and nitrogen-/phosphate-removing wastewater treatment sludge. Besides, Deep Sea Hydrothermal Vent Group 6 (DHVEG-6), Terrestrial Miscellaneous Euryarchaeotal Group, WSA2 and Miscellaneous Crenarchaeotic Group were detected in each sludge sample. This project can provide a archaeal diversity in various sludges.