摘要:SummaryCyanobacteria encompass a diverse group of photoautotrophic bacteria with important roles in nature and biotechnology. Here we characterizedCandidatus“Phormidium alkaliphilum,” an abundant member in alkaline soda lake microbial communities globally. The complete, circular whole-genome sequence ofCa. “P. alkaliphilum” was obtained using combined Nanopore and Illumina sequencing of aCa.“P. alkaliphilum” consortium. Strain-level diversity ofCa.“P. alkaliphilum” was shown to contribute to photobioreactor robustness under different operational conditions. Comparative genomics of closely related species showed that adaptation to high pH was not attributed to specific genes. Proteomics at high and low pH showed only minimal changes in gene expression, but higher productivity in high pH. Diverse photosystem antennae proteins, and high-affinity terminal oxidase, compared with other soda lake cyanobacteria, appear to contribute to the success ofCa.“P. alkaliphilum” in photobioreactors and biotechnology applications.Graphical abstractDisplay OmittedHighlights•Closed genome of the cyanobacteriaCa.P. alkaliphilum from high-pH photobioreactor•Genetic factors lead thisPhormidiumto outcompete other cyanobacteria in photobioreactor•Adaptation to high pH and alkalinity is not linked to specific genes•Strain-level diversity contributesCa.P. alkaliphilum success in changing conditionsGenomics; Microbial biotechnology; Proteomics; Cyanobacteria