Well the whitewash is lime and water mixture a good disinfectant and will kill bacteria, so--lets review a bit
On the interior of a barn which has a high moisture content and in most cases the walls being not insulated will sweat.
Now remember the windows are single pane glass which in cold weather will collect frost an inch thick on cold days, then along comes a warm spell and everything is wet
This barn had no fans for about 45 years of its life and saw many of these wet cycles, but every year the interior was whitewashed early each spring
I was told by the experts, that it was due to these yearly whitewashing cycles that the funguses were not given the chance to create rot
