Pseudosulfitobacter pseudonitzschiae hitchhikes on gliding colonies of Cellulophaga lytica in a multilevel, asymmetric interaction. Pseudosulfitobacter pseudonitzschiae and Cellulophaga lytica coculture

Microbial interactions in natural ecological settings are important for the survival of the species and so complex it makes their study often challenging. Here, we focused on the association of two marine strains: a gliding flavobacterium which displays vivid structural color (C. lytica) and a non-motile, non-structurally colored alphaproteobacterium (P. pseudonitzschiae). A combination of optics, photonics and comparative proteogenomics unfolded ther relationship at multiple levels. This included hitchhiking behavior, structural color modulation, shifts from mutual gain to antagonism, potential cross-feeding and the involvement of quorum-sensing. This dynamic, highly asymmetric, multispecies interaction could have many ecological implications and at the same time great biotechnological interest, for example in developing engineered living materials.