monobacterial

The story

1. Proto-Indo-European*men-
2. Proto-Hellenic*mónwos
3. Ancient Greekμόνος (mónos)
4. Ancient Greekμονο- (mono-)
5. Englishmono-
6. Ancient Greekβακτηρία (baktēría)
7. Ancient Greekβακτήριον (baktḗrion)
8. New Latinbactēria
9. Englishbacteria
10. Proto-Indo-European*h₂el-
11. Proto-Indo-European*h₂élisder.?
12. Englishbacterial
13. English todaymonobacterial

From mono- + bacterial.