Help with myxamoeba encystment and plasmodia formation

[Maxwell]

Recently, I’ve been trying to grow hemitrichia sp. and stemonitis spp. from spores harvested from the wild. I’ve had success in getting the spores to germinate, but I haven’t been able to get the amoeba to form plasmodia. Another problem that I’ve been having is that a couple days after germinating, all of the myxamoeba in the culture will randomly encyst. This may be why I haven’t had luck getting plasmodia as the amoeba don’t stay amoeba long enough to form one, but I’m not entirely sure. I’ve tried culturing the amoeba on both 2% water agar and carrot agar. The incubator I keep the cultures in consistently varies between 24-26 degrees C. And 93-99% RH. (The temp. And RH might not be entirely accurate due to the hygro-thermometer I’m using, but they are pretty close). 

I’d greatly appreciate any help on how to prevent myxamoeba from encrusting, and encouraging the myxamoeba to form plasmodia.

Thanks in advance.

[ian]

Hi

Feed them bugs! the myxamoeba like a lawn of bacteria to feed off - I make a suspension of 1 oat per ml in water, let it sit a few days and pipette about 50 microlitres onto the dish when I add spores.  It can takes weeks to months for plasmodia to form and not all species are able to do a full life cycle in the petri dish. You can also try adding host substrate bits to the agar - Enteridium need something from alder bark to form plasmodia. Cutting your agar into sectors or squares in the dish can also help by forcing them to crowd - there's some sort of quorum signal involved. 

Good luck!