NanoSIMS measurement of resource transfer between Pythium ultimum and Bacillus subtilis

NanoSIMS measurement of 13C, 15N and 18O transfer from hyphae of Pythium ultimum to spores and vegetative cells of Bacillus subtilis. NanoSIMS measurements:- Measurements were carried out in negative extraction mode with a DC source of primary Cs+ ions. - 2 pA beam focused into 70 nm spot- energy of collision was set to 16 keV- scanning: 512 x 512 px matrix with 5msec dwell time per pixelbefore analysis, samples surface of 60 x 60 µm was treated with 10 nA of low-energy (50 eV) Cs+ beam for 10 min- detected secondary ion species: 12C-, 13C-, 16O-, 18O-,12C14N-, 12C15N-, 13C14N-, 32S-- mass resolving power: between 8000 and 12000, exit slit: 40 µm, wide entrance slit: 40 µm, aperture slit: 200 µm, energy slit: cutting 30% of secondary ions in high energy tail - Bacterial and fungal biomass was analysed on a conductive chromium-coated, round-shaped silicon wafer- Experiments were performed in duplicate- fields of either 20 x 20, 30 x 30 or 40 x 40 µm were analysed depending on the arrangement of hyphae and bacterial cells- Data were analysed with the Look@NanoSIMS software