Hi everybody!

I do very usually agrobacterium culture for agroinoculation of plants. I mean I can get virus-infected plants through introduction of agrobcateria with a needle. Normally, I start a culture taking a bit of an agrobacterium glycerol from -80 ºC and adding it to a 50-ml YEP+kanamycin liquid culture..., after 24 h at 28 ºC I harvest the cells by centrifuging and achieve a compact pellet. Finally, I resuspend this pellet in 10 ml of sterile water and inoculate my plants. And normally the thing was going really well. But recently, I tried the same procedure for distinct agrobacteria clones from our collection at -80 ºC, and I could not obtain a compact cell pellet, but a kind of unstable mucus. I tried to refresh the glycerol stocks by plating and picking a colony for starting a new culture..., but a compact pellet never was obtained.

Somebody has any idea about what is going on???

Thanks a lot!!