| Genus | Species | Strains |
|---|---|---|
| Udeniomyces | megalosporus | 10754T |
| punicea | 1337T | |
| pyricola | 10116T 10115 | |
| Uliginosibacterium | gangwonense | 106428T |
| Ulkenia | amoeboidea | 104106 |
| Ulocladium | botrytis | 5370 9210 32273 |
| consortiale | 8823 8824 | |
| Ulvibacter | antarcticus | 102682T |
| Umbelopsis | angularis | 5426 6744 8186 8187 |
| gibberispora | 107819 | |
| isabellina | 7873T 6336 6739 7824 7874 7884 8183 8286 8308 8309 8572 105998 | |
| nana | 8190 8794 100664 102295 105995 | |
| ramanniana | 7825 8184 8185 8287 102500 102501 102502 105996 107816 | |
| roseonana | 102314 | |
| vinacea | 6738 7875 100665 105997 | |
| Umezawaea | tangerina | 16184T |
| Uncinocarpus | reesii | 32079 100320 |
| unicellular-rhodophyte (class: Rhodophyceae) |
102723 102937 102938 102939 | |
| unicellular-ulvophyte (class: Ulvophyceae) |
102767 102779 102780 102783 102828 102836 102900 102901 | |
| Ureibacillus | composti | 106533T |
| suwonensis | 106534T | |
| thermophilus | 106535T | |
| thermosphaericus | 108682 | |
| Urnula | craterium | 30137 31627 |
| Urocystis | agropyri | 32750 32751 |
| Ustilaginoidea | virens | 5923 9175 31672 31673 |
| Ustilago | coicis | 32733 32734 |
| crus-galli | 31947 32737 32738 | |
| cynodontis | 7530 9727 9758 | |
| esculenta | 9887 105094 105096 105097 105098 | |
| kusanoi | 9070 | |
| maydis | 5346 6907 | |
| neglecta | 32748 32749 | |
| onumae | 9071 | |
| rabenhorstiana | 8995 | |
| scitaminea | 32729 32730 | |
| shiraiana | 8809 30149 | |
| sphaerogena | 31946 32735 32736 | |
| syntherismae | 32724 32725 32726 | |
| trichophora | 100155 100156 100157 100158 100159 100160 | |
| utriculosa | 32739 32740 | |
| violacea | 9216 9218 30031 | |
| Uthatobasidium | fusisporum | 6281 |