| Xanthobacter autotrophicus | 14758, 102463T |
| Xanthobacter flavus | 14759T |
| Xanthobacter sp. | 15493, 15494, 115927, 116939, 116940 |
| Xanthomonas arboricola | 3780, 13557 |
| Xanthomonas campestris | 13303, 13551 |
| Xanthomonas citri | 3781, 3829, 3835, 12213 |
| Xanthomonas cucurbitae | 13552 |
| Xanthomonas oryzae | 3312, 3510, 3827, 3828, 3833, 3834, 3995, 3996, 3997, 3998, 3999, 12000, 12001, 12002 |
| Xanthomonas phaseoli | 13553, 13554 |
| Xanthomonas physalidicola | 13555 |
| Xanthomonas pisi | 13556 |
| Xanthomonas sp. | 14591, 115641 |
| Xanthomonas translucens | 13559 |
| Xanthophyllomyces dendrorhous | 10130 |
| Xanthothecium peruvianum | 8500, 9865 |
| Xenobotrytis acaducospora | 102034 |
| Xerochrysium xerophilum | 117031 |
| Xeromphalina cauticinalis | 7633, 9358 |
| Xeromyces bisporus | 112787 |
| Xerula pudens | 9574, 30335 |
| Xylanibacterium ulmi | 106152T |
| Xylanimicrobium pachnodae | 107786T |
| Xylanimonas allomyrinae | 113052T |
| Xylanimonas cellulosilytica | 107835T |
| Xylanimonas protaetiae | 113053T |
| Xylaria angulosa | 33288 |
| Xylaria aristata | 104662, 104667 |
| Xylaria badia | 104656, 104660 |
| Xylaria berteroi | 112119 |
| Xylaria carpophila | 33013 |
| Xylaria cf. amphithele | 104702 |
| Xylaria cubensis | 104653, 104655, 104661, 104669, 104681, 104693, 104722, 104724, 107985, 107986, 107987, 107988, 107991, 107992, 107994, 107995, 107996, 107997, 107998, 107999, 108000, 108007, 108008 |
| Xylaria escharoidea | 104735, 104736 |
| Xylaria grammica | 104680, 104688, 104697, 104709, 104711, 104721, 104727, 104730, 104731, 104732, 107983, 107984, 107989 |
| Xylaria juruensis | 104663, 104664, 104665 |
| Xylaria laevis | 104659 |
| Xylaria polymorpha | 9780, 30369 |
| Xylaria sp. | 104428, 104429, 104430, 104431, 104432, 104658, 104668, 104671, 104672, 104673, 104674, 104676, 104677, 104678, 104679, 104682, 104683, 104684, 104685, 104687, 104690, 104691, 104694, 104695, 104705, 104706, 104707, 104708, 104710, 104715, 104718, 104719, 104720, 104729, 104996, 107815, 107824, 112117 |
| Xylariaceae sp. | 113725, 113728, 113731, 113732, 113733 |
| Xylobolus frustulatus | 4932 |
| Xylobolus spectabilis | 7650 |
| Xylobolus subpileatus | 7076 |
| Xylogone sphaerospora | 9516T, 31724 |
| Xylomyces sp. | 105263 |