Attachment of Bacillus subtilis to the hyphae of Aspergillus niger results in altered metabolism and defense mechanisms in both partner

Transcriptome comparison of Bacillus subtilis NCIB3610 attached to the hyphae of Aspergillus niger CB 119.1 compared to Bacillus subtilis NCIB3610 cells in the supernatant of the same culture. Detailed description (other than provided below) of growth conditions, RNA preparation, cDNA synthesis and hybridization conditions can also be found in the submitted paper. B subtilis NCIB3610 cells were grown in the presence of Aspergillus niger CB 119.1 hyphae for 3 hours. The mycelium and the attached bacteria were separated from the non-attached B. subtilis cells via filtration through Miracloth. The mycelia and attached bacteria were briefly rinsed with TY medium, dried, and the sample was frozen in liquid nitrogen. Bacterial cells in the flow-through medium fraction were harvested by centrifugation at 10.397 g for 1 min. To extract RNA mainly from the bacterial cells, lysozyme solution and RiboLock (Thermo Scientific) was added followed by incubation at 37 C for 30 minutes. Further RNA extraction was performed with the Macaloid/Roche method as described before (van Hijum et al., 2005, Kovács and Kuipers, 2011) but omitting the bead beater treatment and using RiboLock.