Effects of dispersal on species distribution, abundance, diversity and interaction in a bacterial biofilm metacommunity

Aims Dispersal effects on biofilms have not been adequately studied despite their strong potential impacts on biofilm development. We investigated the effects of dispersal on biofilm metacommunity. Methods and results A bacterial consortium was allowed to form biofilms on 12 glass beads attached to disposable plates (compartmentalized or not), and biofilms were scrutinized on days 5, 10 and 15 using quantitative PCR and MiSeq sequencing. Biofilm population density was lesser by 2 orders of magnitude on day 5 when dispersal was allowed (p < 0.05). Then, the population rapidly increased by 4.4 orders with dispersal (p < 0.05) but did not change without dispersal. Community analyses revealed that dispersal increased the species diversity at all sampling times (p < 0.05). Dispersal affected the community structure and increased the homogeneity of local communities (p < 0.05). Distance-decay analysis showed that dispersal reduced the dissimilarity among local communities at all distance levels. Furthermore, dispersal reduced the variability of diversity, population and community structure. Network analysis revealed that dispersal increased the clustering coefficient, network density and connectivity. Conclusions Dispersal increased the species diversity, population and interaction and reduced the variability of the diversity, population and structure among local communities. Significance and Impact of Study Our results suggest that dispersal can induce the niche complementarity and mass effects.