Hallo,

I'm using 1x YNB medium (0.67 g/ 100 mL) supplied with an Aminoacid mix.

As my medium was going to finish I prepared new one, and set up two cultures, one with the "old" medium, i was previously using, and one with the new medium.

I prepared and cultured it parallel, somhow yeast (BY4741) was growing in the culture with the "old" medium but not in the freshly prepared medium.

I repeated the medium preparation to make sure I haven't make a mistake. But I recived the same result.

I also tested freshly prepared Aminoacids and colonies from different paltes, to exclude the option that the trouble is caused from these factors.

But again, yeast was growing in "old" medium but not in the fresh medium.

Further I tested, freshly prepared 10xYNB in comparison to the "old" medium, again nothing grew in the diluted 10xYNB medium.

I took the brooth from the same container, so a difference in charge can be excluded.

Does anyone ever observed anything like this or does anyone has an advice for me?

Thanks!