Fig. 1. Growth of Nostoc sp. cyanobacteria is promoted by associated heterotrophic bacteria, particularly under inorganic carbon-limited conditions.
A Axenic N. punctiforme PCC 73102 was unable to grow under low carbonate concentrations, whereas Nostoc sp. KVJ3 and KVJ2 thrived. Pictures were taken after seven days of cultivation on plates. B Microbiome analysis using 16S rRNA amplicon sequencing revealed a diversity of heterotrophic bacteria in Nostoc sp. KVJ2 and KVJ3, which were dominated by Alphaproteobacteria. C The isolate A.tumefaciens Het4, which was isolated from strain KVJ3 (Supplementary Fig. 1) promotes growth of N. punctiforme PCC 73102 under carbon-limited conditions. See Supplementary Fig. 3 for growth curves and digital image analysis.