Hello everyone

I'm working on biodegradation of a toxic substance with pure culture as my master thesis in batch flasks, as you know during this process I transfer culture from one subculture to another one with concomitant increase in concentration of the toxic substance.

The problem that I faced with is that one of my subcultures failed and I need to repeat it with a subculture that was kept in refrigerator for two weeks, I tried repeating the subculture two times and the culture didn't grow. Does anyone have the same experience that could help me ?