Table 1. List of functional groups in activated sludge.
| Functional group | Subgroup | Genusa | Reference sequence number in databaseb |
| Nutrient remediators | AOB | Nitrosomonas | 48/78(61.5%) |
| Nitrosospira | 68/68(100%) | ||
| Nitrosococcus | 19/19(100%) | ||
| NOB | Nitrobacter | 73/80(91.3%) | |
| Nitrospira | 21/21(100%) | ||
| Denitrifier | Acidovorax | 208/233(89.3%) | |
| Arcobacter | 92/92(100%) | ||
| Azoarcus | 57/64(89.0%) | ||
| Comamonas | 221/244(90.6%) | ||
| Curvibacter | 12/14(85.7%) | ||
| Dechloromonas | 31/34(91.2%) | ||
| Hyphomicrobium | 61/65(93.8%) | ||
| Meganema | 2/2(100%) | ||
| Methylobacillus | 10/13(76.2%) | ||
| Methylophilus | 26/29(89.7%) | ||
| Paracoccus | 308/318(96.9%) | ||
| Rhodobacter | 99/137(72.3%) | ||
| Rhodococcus | 783/800(97.9%) | ||
| Thauera | 61/61(100%) | ||
| Zoogloea | 31/36(86.1%) | ||
| PAO | ‘Accumulibacter’ | 0/12(0%) | |
| Tetrasphaera | 21/21(100%) | ||
| GAO | ‘Competibacter’ | 0/1(0%) | |
| Defluviicoccus | 2/2(100%) | ||
| Hydrolyser | Saprospira | 4/11(36.4%) | |
| Lewinella | 19/19(100%) | ||
| Bulking and foaming group | Bulking bacteria | ‘Microthrix’ | 18/18(0%) |
| Acinetobacter | 1,677/1,690(99.2%) | ||
| Aquaspirillum | 4/11(36.4%) | ||
| Beggiatoa | 10/26(38.5%) | ||
| Caldilinea | 2/2(100%) | ||
| Flexibacter | 22/74(29.7%) | ||
| Gordonia | 223/225(99.1%) | ||
| Haliscomenobacter | 7/8(87.5%) | ||
| Leucothrix | 4/5(80%) | ||
| Moraxella | 84/123(68.3%) | ||
| Sphaerotilus | 16/16(100%) | ||
| Thiothrix | 70/72(97.2%) | ||
| Trichococcus | 40/40(100%) | ||
| Foaming bacteria | Isosphaera | 2/12(16.7%) | |
| Mycobacterium | 1,063/1,068(99.5%) | ||
| Nocardia | 768/777(98.8%) | ||
| Rhodococcus | 783/800(97.9%) | ||
| Skermania | 12/12(100%) | ||
| Tetrasphaera | 21/21(100%) | ||
| Potential pathogen | Aeromonas | 768/770(99.7%) | |
| Bordetella | 186/192(96.9%) | ||
| Borrelia | 322/322(100%) | ||
| Brucella | 187/201(93.0%) | ||
| Campylobacter | 450/452(99.6%) | ||
| Chlamydia | 72/78(92.3%) | ||
| Chlamydophila | 30/30(100%) | ||
| Clostridium | 1,586/1,694(93.6%) | ||
| Corynebacterium | 614/624(98.4%) | ||
| Escherichia | 710/731(97.1%) | ||
| Enterococcus | 843/856(98.5%) | ||
| Francisella | 100/101(99.0%) | ||
| Haemophilus | 882/964(91.5%) | ||
| Helicobacter | 415/418(99.3%) | ||
| Klebsiella | 517/806(64.1%) | ||
| Legionella | 193/206(93.7%) | ||
| Leptospira | 315/316(99.7%) | ||
| Listeria | 190/190(100%) | ||
| Mycobacterium | 1,063/1,068(99.5%) | ||
| Mycoplasma | 356/533(66.8%) | ||
| Neisseria | 1,229/1,235(99.5%) | ||
| Pseudomonas | 5,819/6,057(96.1%) | ||
| Rickettsia | 164/164(100%) | ||
| Salmonella | 339/365(92.9%) | ||
| Serratia | 629/652(96.5%) | ||
| Shigella | 288/288(100%) | ||
| Staphylococcus | 1,207/1,214(99.4%) | ||
| Streptococcus | 2,289/2,311(99.0%) | ||
| Treponema | 1,074/1,089(98.6%) | ||
| Vibrio | 1,533/1,705(89.9%) | ||
| Yersinia | 311/315(98.7%) | ||
| Total | 29,930/31,522(94.9%) |
a. Genus names with single quote marks were candidate genera that could not be classified by RDP classifier. They are kept in the final database.
b. The first number indicates the sequences that could be identically classified in RDP at genus level (except for the candidate genera) and thus are kept in the final database. The second is the number of total downloaded sequences from Greengenes database. Percentage showed the portion of identically classified sequences.