Tecnai g20 cryo

To evaluate ideal growth, the strain Marseille‐P2341^T was cultivated on Columbia agar with 5% sheep's blood (bioMérieux) and incubated at different temperatures (25, 28, 37, 45, and 56°C) in an aerobic atmosphere with or without 5% CO₂, and in anaerobic and microaerophilic atmospheres, using GENbag Anaer and GENbag microaer systems (bioMérieux). The salinity and pH conditions were also tested at different concentrations of NaCl (0%, 5%, 15%, and 45%) and different pH (5, 6, 6.5, 7, and 8.5).
Oxidase and catalase tests, Gram‐stain, motility, and sporulation were performed using standard procedures (Murray, Baron, Jorgensen, Landry, & Pfaller, 2007). To observe cell morphology, they were fixed with 2.5% glutaraldehyde in 0.1 mol/L cacodylate buffer for at least 1 hr at 4°C. A drop of cell suspension was then deposited for approximately 5 min on glow‐discharged formvar carbon film on 400 mesh nickel grids (FCF400‐Ni, EMS). The grids were dried on blotting paper and cells were negatively stained for 10 s with 1% ammonium molybdate solution in filtered water at RT. Electron micrographs were acquired using a Tecnai G20 Cryo (FEI) transmission electron microscope operated at 200 keV.

To observe the cell morphology, transmission electron microscopy of the strain was performed using a Tecnai G20 Cryo (FEI company, Limeil‐Brevannes, France) at an operating voltage of 60 Kv after negative staining. Gram staining was performed and observed using a photonic microscope Leica DM2500 (Leica Microsystems, Nanterre, France) with a 100X oil‐immersion objective (Atlas & Snyder, 2011). The motility of the strain was assessed by the Hanging Drop method. The slide was examined using a DM1000 photonic microscope (Leica Microsystems) at 40×. Sporulation was tested following a thermic shock at 80°C during 20 min, and the endospore formation was visualized using a Tecnai G20 Cryo transmission electron microscope (FEI company, Limeil‐Brevannes, France) at an operating voltage of 60 Kv after negative staining.