Hi there,
I am working with algae biomass cultivation and I use BG-11 as the growth medium. I wanted to ask, if the stock solutions used for the medium preparation can be stored in a refrigerator for extended time period? Are all of those solutions stable?
The thing is that last time I prepared my medium, I used stock solutions from the previous preparation. As a result I got medium with elevated pH (8.4) and after autoclaving it, there were some precipitate present in the flask.
Could anybody share their experience regarding this problem?
Hello sir..
I cannot comment on the different ingredients of the medium and its individual stability, but yes I have definitely used the ready-made preparation of the medium by Hi-Media and it really works well.
Regards and best wishes.
BG-11 is rich with phosphates. They precipitate with Ca2+ and Mg2+, at least. I would suggest to use so called "cold" sterilization of the stock solution using a membrane filters with pores around 0.22 um. Do not postpone that longer than 1-2 days. Some microbes feel them self well in a fridge. You can autoclave water and mix it with cold-sterilized stock solution in any proportion. That will prevent the generation of a precipitate along with minimal changes of pH because hot sterilization stimulates the escape of CO2 from the newly prepared medium. Good luck!
We commonly keep phosphate, ferric ammonium citrate and carbonate separate from the other components. One can either mix everything together before autoclaving (however, expect precipitates; not a biggie assuming you mix it right before you use it) or autoclave BG-11 (-P, Fe, CO3) and P, Fe and CO3 separately.
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