Project description:A cyanobacterium, Thermosynechococcus elongatus BP1, was cultured with a heterotroph, Meiothermus ruber strain A, under a variety of conditions. A gene co-expression approach was used to infer a network of T. elongatus and M. ruber genes, with a focus on those genes from different species that were co-expressed, highlighting potential points of coordination and interaction.
Project description:We examine how the transcriptome of Prochlorococcus strain NATL2A changes in response to extended light deprivation, both when grown alone and in the presence of a naturally co-occurring heterotroph, Alteromonas macleodii MIT1002.
Project description:Microbial autotroph-heterotroph interactions influence biogeochemical cycles on a global scale, but the diversity and complexity of natural systems and their intractability to in situ manipulation make it challenging to elucidate the principles governing these interactions. The study of assembling phototrophic biofilm communities provides a robust means to identify such interactions and evaluate their contributions to the recruitment and maintenance of phylogenetic and functional diversity overtime. To examine primary succession in phototrophic communities, we isolated two unicyanobacterial consortia from the microbial mat in HotLake, Washington, characterizing the membership and metabolic function of each consortium. We then analyzed the spatial structures and quantified the community compositions of their assembling biofilms. The consortia retained the same suite of heterotrophic species, identified as abundant members of the mat and assigned to Alphaproteobacteria, Gammaproteobacteria, and Bacteroidetes. Autotroph growth rates dominated early in assembly, yielding to increasing heterotroph growth rates late in succession. The two consortia exhibited similar assembly patterns, with increasing relative abundances of members from Bacteroidetes and Alphaproteobacteria concurrent with decreasing relative abundances of those from Gamma proteobacteria. Despite these similarities at higher taxonomic levels, the relative abundances of individual heterotrophic species were substantially different in the developing consortial biofilms. This suggests that, although similar niches are created by the cyanobacterial metabolisms, the resulting webs of autotroph-heterotroph and heterotroph-heterotroph interactions are specific to each primary producer. The relative simplicity and tractability of the Hot Lake unicyanobacterial consortia make them useful model systems for deciphering interspecies interactions and assembly principles relevant to natural microbial communities.