1. A new fluorescence-based approach for direct visualization of coat formation during sporulation inBacillus cereus
- Author
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Armand Lablaine, Stéphanie Chamot, Mónica Serrano, Cyrille Billaudeau, Isabelle Bornard, Rut Carballido-Lopez, Frédéric Carlin, Adriano O. Henriques, Véronique Broussolle, Sécurité et Qualité des Produits d'Origine Végétale (SQPOV), Avignon Université (AU)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Instituto de Tecnologia Química e Biológica António Xavier (ITQB), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), MICrobiologie de l'ALImentation au Service de la Santé (MICALIS), AgroParisTech-Université Paris-Saclay-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Unité de Pathologie Végétale (PV), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), INRAE and the PACA Region, Perdiguier grant of Avignon University, Part of this work was supported by the microscopy facilities of the Platform 3A, funded by the European Regional Development Fund, the French Ministry of Research, Higher Education and Innovation, the Provence-Alpes-Côte d’Azur region, the Departmental Council of Vaucluse and the Urban Community of Avignon, grants PEst-OE/EQB/LA0004/2011 to AOH, by project LISBOA-01-0145-FEDER-007660 ('Microbiologia Molecular, Estrutural e Celular') funded by FEDER funds through COMPETE2020 – 'Programa Operacional Competitividade e Internacionalização', project PPBI – Portuguese Platform of BioImaging (PPBI-POCI-01-0145-FEDER-022122) co-funded by national funds from OE – 'Orçamento de Estado' and by European funds from FEDER – 'Fundo Europeu de Desenvolvimento Regional', grant of the MICA division, and European Project: 772178,BACTIN
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[SDV.EE.SANT]Life Sciences [q-bio]/Ecology, environment/Health ,sporulation ,[SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology ,Bacillus cereus ,microscopy ,[SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic ,[SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology ,Pathogenic Bacteria - Abstract
The pathogenic bacteriaBacillus cereus,Bacillus anthracisandBacillus thuringiensisform spores encased in a protein coat surrounded by a balloon-like exosporium. These structures mediate spore interactions with its environment, including the host immune system, control the transit of molecules that trigger germination and thus are essential for the spore life cycle. Formation of the coat and exosporium has been traditionally visualized by transmission electronic microscopy on fixed cells. Recently, we showed that assembly of the exosporium can be directly observed in liveB. cereuscells by super resolution-structured illumination microscopy (SR-SIM) using the membrane MitoTrackerGreen (MTG) dye. Here, we demonstrate that the different steps of coat formation can also be visualized by SR-SIM using MTG and SNAP-cell TMR-star dyes duringB. cereussporulation. We used these markers to characterize a subpopulation of engulfment-defectiveB. cereuscells that develops at a suboptimal sporulation temperature. Importantly, we predicted and confirmed that synthesis and accumulation of coat material, as well as synthesis of the σK-dependent protein BxpB, occur in cells arrested during engulfment. These results suggest that, unlike the well-studied model organismBacillus subtilis, the activity of σKis not strictly linked to the state of forespore development inB. cereus.
- Published
- 2023
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