I think do not add Silicate and stop using glass bottles for growing the other guys. If you use no dissolved silicate and still the glass bottle, that also leach some silicate which can support diatom growth. If you use may polycarbonate bottles without dissolved silicate, may help you. Good luck

Recently we killed diatoms in our Nannochloropsis culture by adding 10 mM GeO2 to growth F/2 medium. Works fine!

Germanium di oxide treatment is the only way

Hello Drs Gennady and Subramanian,

both of your answers are quite interesting and I would like to know if there is no silicate in the culture how do the diatom still survive? and could you please also tell how Germanium di oxide work to remove diatom from cyanobacterial growth?

Thanks and regards,

Haimanti

You have alraedy received the answer. Ge is a competive inhibitor of Silicate systems and is classically used as a diatom inhibitor. Look in the literatue for papers by Ben Volcani in the 1970s about. Work by Farouk Azam is pertinent too, Both workers worked at Scripps Inst of Oceanogr. My handbook ( Phycological Methods, J Stein published by Cambridge U Press) book mentions Joyce Lewin 1966 and 10mg/L GeO2

Hello Keith,

Thanks a lot for your input regarding the activity of Ge and the related literature. Yes, there are several information explaining the same, Once thanks again.

Regards,

Haimanti

Like others have mentioned...germanium dioxide is a great solution. I use 1g/L stock and add 5 ml to one litre media (final conc. 5mg/l) works everytime...