We applied bar-coded 16S rRNA gene amplicon sequencing for species identification. Bacterial diversity in samples from A.aerophoba, P.ficiformis and C.candelabrum was analysed. The cultivable bacterial fraction from these sponges was studied on five different media in the form of 60 communities scraped from plates without antibiotics, as well in the form of individual isolates that were grown on these media supplemented with either one or two of 14 different antibiotics.