Stress-induced formation of cell wall-deficient cells in filamentous actinomycetes

• DOI: 10.1038/s41467-018-07560-9
• Publication Date: 2018-11-28T16:07:06Z
• Authors: Karina Ramijan; Eveline Ultee; Joost Willemse; Zheren Zhang; Joeri A. J. Wonde...; Anne van der Meij; Doris Heinrich; Ariane Briegel; Gilles P. van Wezel; Dennis Claessen
• Keywords: 0301 basic medicine; Cell biology; Sucrose; Microbial Viability; Whole Genome Sequencing; Science; Q; Adaptation, Biological; L Forms; Penicillins; Spheroplasts; Bacterial Physiological Phenomena; Microbiology; Article; Actinobacteria; 03 medical and health sciences; Bacterial Proteins; Cell Wall; Osmotic Pressure; RNA, Ribosomal, 16S; Sequence Alignment; Gene Deletion; Phylogeny

AbstractThe cell wall is a shape-defining structure that envelopes almost all bacteria and protects them from environmental stresses. Bacteria can be forced to grow without a cell wall under certain conditions that interfere with cell wall synthesis, but the relevance of these wall-less cells (known as L-forms) is unclear. Here, we show that several species of filamentous actinomycetes have a natural ability to generate wall-deficient cells in response to hyperosmotic stress, which we call S-cells. This wall-deficient state is transient, as S-cells are able to switch to the normal mycelial mode of growth. However, prolonged exposure of S-cells to hyperosmotic stress yields variants that are able to proliferate indefinitely without their cell wall, similarly to L-forms. We propose that formation of wall-deficient cells in actinomycetes may serve as an adaptation to osmotic stress.