The strain is Candida tropicalis. It has been stored in 4 degree refrigerator for a year. Now we want to see if it is possible to revive the strain and make it function again. I tried to culture it in seed medium and it did grow a little bit (around 8OD after 12h culture). But it did not grow in the fermentation medium and did not produce any products or consume any carbon source as it used to be. So does anyone have some revival suggestion that might revive the strain better? Thank a lot.
Dear Qianwei Li,
You should repeat the reviving process in the seed medium untill you get higher OD values. I think 3-4 times will be enough. After gaining that lively Candida tropicalis cultures you can use the production medium.
BR,
Dr. Silbir
Kindly check https://sfamjournals.onlinelibrary.wiley.com/doi/pdf/10.1111/jam.12710
Dear Li
I agree with Selim, you should try again with seed medium and you get higher OD values. After gaining that lively Candida tropicalis cultures can be used for further experiments. Also, I would suggest you to keep the cultures in the future for storage at -200C instead of 40 C as the revival chances are high in -200C.
Thank You
All the Best!
Estimado Qianwei Li, despues del 2018, yo he guardado bacterias termófilas y hace más de una semana, las estoy reviviendo, primero en cultivo con medio líquido por 3 a 4 días, se nota que va aumentando la absorbancia, y luego paso a cultivarlas en medio sólido, para ello utilizo varios sustratos inductores, para obtener sus enzimas, y si forman sus halos a las 24 horas. Se que tu bacteria no es termófila, pero te cuento mi experiencia. Buena suerte.
continue subculture it before use the culture in production scale in complex medium
I agree with Osama. Subculturing allows for increased growth and multiplication of cells in the culture.
For strains that are used daily or weekly, cultures grown on agar slants or plates can be stored in a refrigerator assuming that precaution has been taken to avoid contamination. Sealing the plates not only helps to prevent molds from sneaking into the plates, but it slows the agar from drying.For long term storage, microorganisms are cryopreserved at temperatures below freezing (-20°C, -80°C, or liquid nitrogen) or freeze dried (lyophilized). Cryopreservation is suitable for a wide range of bacteria, algae, fungi, viruses, and protozoa.
It is interesting how difficult some microorganisms are to maintain without continual culturing or the exact conditions for storage. The increase in OD at the beginning is most likely due to the release of cell contents as dead cells burst providing you with a glimmer of hope that growth is occurring. The reality is the strain is most likely dead. You
For freeze-dried fungi, use a Pasteur pipette to add approximately 0.5 to 1.0 mL sterile water to the inner vial of a double vial or to a serum vial (Preceptrol®). Then, draw up the entire contents into the pipette and transfer to a test tube with about 5 to 6 mL sterile water. Let the yeast or fungus rehydrate for at least a couple hours before transferring to broth or solid agar; longer rehydration (e.g., overnight) might increase the viability of some fungi. Incubate at the recommended temperature. Keep in mind that some cultures may exhibit a prolonged lag period and should be given twice the normal incubation time before discarding as nonviable. Save the mixture of lyophilized material and water until you know you have growth.
Please refer to the below link.
https://www.atcc.org/how_to_revive_cultures.aspx#fungi
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