We have successfully developed a protocol for growing co-cultures of heterotrophic bacteria andcyanobacteria. We tested phylogenetically diverse heterotrophic bacteria (Vibrio, Pseudoalteromonas, Alteromonas, Flavobacterium) with two cyanobacteria, one belonging to the coastal clade (CC9311) and the other to the oceanic clade (WH8102). Our data indicate that SWAT3 (Vibrio), ATW7 (Alteromonas),Pseudoalteromonas flavipulchra (Pesudoalteromonas) strongly inhibit the growth of CC9311 and WH8102 whereas BBFL7 (Flavobacterium) doesn’t. This suggests that some Synechococcus-bacteria associations are antagonistic in nature. Thus, some bacteria may regulate Synechococcus-based primary production as well as contribute to variations in clade-specific productivity. These are important findings and we are currently elucidating the mechanism by which bacteria inhibit/kill Synechococcus.
Figure 1: Co-culture growth effect experiments among WH8102 and CC9311 Synechococcus strains and heterotrophic bacteria in SN medium.
Bacteria-cyanobacteria associations are phylogenetically diverse