The morphology of raw and treated cells was imaged using SEM
(Hitachi SU6600 analytical FE-SEM, Hitachi High-Technologies in
America, CA) operatingat2 kVor 5 kV.Freeze-dried microalgaesamples
were mounted on a specimen stub with adhesive tape for sputter-
coating with platinum in a coating machine (Hummer 6.2 Sputter
System, Anatech USA, Union City, CA) under an Argon atmosphere
before observation. In addition, optical microscopic images of the intact
and ruptured cells were obtained using a
fl
uorescence microscope
(Axioskop 2 plus, Carl Zeiss Microscopy, LLC, Thornwood, NY) equipped
with an AxioCamMRc5 camera (Carl Zeiss Microscopy, LLC, Thornwood,
NY) in bright
fi
eld mode.