Fig. 2

Interaction between N. oceanica and Mortierella mycelium co-cultivated in f/2 medium. Fungal mycelium was added to a log-phase Noc culture grown in a flask and then the mixture was incubated for 6 days in f/2 medium. Scanning electron microscopy was performed to investigate the interaction between N. oceanica (Noc) cells and M. elongata AG77 (a) and NVP64 (b). Noc cells are attached to the fungal mycelium as shown in the top panel. Higher magnification micrographs show that Noc cells have a highly structured cell wall with protrusions, with which they attach to the rough surface of the fungal cell wall. The red arrowheads indicate tube-like structures that connect the algal and fungal cell walls. c Morchella americana 3668S mycelium collected from a Noc-3668S culture after 6-day co-cultivation