Spatial and temporal variability of the bacterial community in different chemotypes of the New Zealand marine sponge Mycale hentscheli.

Molecular fingerprinting of 16S rRNA genes using terminal restriction fragment length polymorphism (T-RFLP) and denaturing gradient gel electrophoresis (DGGE) was used to characterize the temporal and spatial variability among sponge-associated bacteria from Mycale hentscheli having distinct bioactive chemotypes. Cluster analysis of T-RFLP and DGGE profiles from M. hentscheli chemotypes largely grouped sponge microbial diversity to their distinct chemotype pattern. Repeat sampling of individual M. hentscheli at one location over a 21-month period showed that the T-RFLP profiles from individual sponges had similarity indices ranging from 60% to 82% and calculated DGGE similarities between 23% and 95%. However, a portion (>35% from DGGE and >19% from T-RFLP) of the microbial community from M. hentscheli appeared to be spatially conserved through all M. hentscheli populations. Sequence analysis of DGGE band fragments showed a similarity among the bands originating from different individuals, different times, and different locations. The sponge-associated relationship of these bands was confirmed, with sequences having similarity to sponge-associated bacteria reported from global locations. This study highlights the spatial and temporal complexity in the distribution of bacterial communities associated with different chemotypes of the marine sponge M. hentscheli.