Cell specialization in cyanobacterial biofilm development revealed by expression of a cell-surface and extracellular matrix protein

作者：Alona Frenkel, Eli Zecharia, Daniel Gómez‐Pérez, Eleonora Sendersky, Yevgeni Yegorov, Avi Jacob, Jennifer I. C. Benichou, York‐Dieter Stierhof, Rami Parnasa, Susan S. Golden, Eric Kemen, Rakefet Schwarz · 发表于：npj Biofilms and Microbiomes · 年份：2023 · DOI：10.1038/s41522-023-00376-6 · 被引用次数：15 · 研究领域：Bacterial biofilms and quorum sensing、Microbial Community Ecology and Physiology、Biocrusts and Microbial Ecology

Cyanobacterial biofilms are ubiquitous and play important roles in diverse environments, yet, understanding of the processes underlying the development of these aggregates is just emerging. Here we report cell specialization in formation of Synechococcus elongatus PCC 7942 biofilms-a hitherto unknown characteristic of cyanobacterial social behavior. We show that only a quarter of the cell population expresses at high levels the four-gene ebfG-operon that is required for biofilm formation. Almost all cells, however, are assembled in the biofilm. Detailed characterization of EbfG4 encoded by this operon revealed cell-surface localization as well as its presence in the biofilm matrix. Moreover, EbfG1-3 were shown to form amyloid structures such as fibrils and are thus likely to contribute to the matrix structure. These data suggest a beneficial 'division of labor' during biofilm formation where only some of the cells allocate resources to produce matrix proteins-'public goods' that support robust biofilm development by the majority of the cells. In addition, previous studies revealed the operation of a self-suppression mechanism that depends on an extracellular inhibitor, which supresses transcription of the ebfG-operon. Here we revealed inhibitor activity at an early growth stage and its gradual accumulation along the exponential growth phase in correlation with cell density. Data, however, do not support a threshold-like phenomenon known for quorum-sensing in heterotrophs. Tog...