A colleague asked me the following question and I suggested to post it in RG.
She isolated a strain of a new Koliella species (Chlorophyta, Trebouxiophyceae), but the culture has been contaminated by fungi. However, to carry out further genetical analyses she needs a pure culture. Does anybody know a practical way to remove the fungi from an algae culture? Is there a fungicide available that does not affect the growth of green algae?
Thank you very much -- Thomas
Hi Thomas,
I have successfully used an antibiotic and antimycotic solution (final concentrations 5 100 IU mL21 penicillin, 100 m g mL21 streptomycin, and 0.25 m g mL21 amphotericin B;Mediatech, Inc.) added into the medium immediately before inoculation at a 1% concentration (final volume) to ensure cultures remained free of bacteria and fungi. As most things it does not work for all strains of micro algae but worked well for me for a variety of dinoflagellates as well as other Eukaryotes such as Aureococcus anophagefferens as well as Isochrisis galbana. Let me know if you need more advice. Good luck.
Adjust pH of culture medium to 2 for 24 hours, after adjust normally pH value
We usually use benomyl and/or carbendazim, added to a nutrient-poor solid agar medium. In order to avoid the toxicity effect, we try different dilutions of the fungicide in parallel. The dosis at which the fungicides will be effective against the fungus, without affecting the alga will depend on each strain tested. Last time I tried for a green coccoid alga, the active concentrations were in the range of 1 microg/mL. After 1 week or so, you should try to pick some clean algal cells with a sterile dissection needle and tranfer them individually onto a fresh agar plate without fungicide.
Hi Thomas,
I have successfully used an antibiotic and antimycotic solution (final concentrations 5 100 IU mL21 penicillin, 100 m g mL21 streptomycin, and 0.25 m g mL21 amphotericin B;Mediatech, Inc.) added into the medium immediately before inoculation at a 1% concentration (final volume) to ensure cultures remained free of bacteria and fungi. As most things it does not work for all strains of micro algae but worked well for me for a variety of dinoflagellates as well as other Eukaryotes such as Aureococcus anophagefferens as well as Isochrisis galbana. Let me know if you need more advice. Good luck.
There are some useful tips on the Chlamy.org website (http://www.chlamy.org/methods/cleanup.html) that might be useful for your Koliella strains. I personally think the best way to isolate clean cells is to pick them individually from agar plates under a dissecting microscope. It might take a few rounds but I found this to be the most effective way of cleaning contaminated Chlamydomonas cultures. Adding some fungicide to the agar might help keep the fungus at bay whilst your cells grow on agar ready to be cleaned. Good luck.
The use of fungicides and antibiotics is needed, but cycloheximide should excluded because it a strong inihibitor of proteins synthesis in eucaryotics cells. By contrast if cyanobacteria are contaminated by fungi, cycloheximde could used!!!! Good luck
Dear colleagues,
I see -- it seems that this is not very different from how my other colleagues handle their protozoans. But, I am aware that there always some specifics that need to be respected...
To sum up, I'm optimistic that your suggestions will definitely help to find a solution.
Many thanks for all your qualified answers and suggestions!
Thomas
I search to solution to this problem but can i used in large scale production may be cost effective did you another alternative ?
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