The freeze-dried samples were sputter coated with gold (JEOL JFC 1100 E ion sputtering device) and photographed at an accelerating voltage of 15 kV and magnifications of 35–10,000
The freeze-dried samples were sputter coated withgold (JEOL JFC 1100 E ion sputtering device) and photographed atan accelerating voltage of 15 kV and magnifications of 35–10,000