We used to deal with crazy amounts of black mould, in various properties I have worked in. One main cause was because there was not much ventilation (circulation of air) which affected those particular areas and resulted in black mould. We used propriety paints with all kinds of recommended additives which was supposed to cure the problem, which I hasten to say, never worked. Another recommendation was to wash off the black mould with a watered down solution of disinfectant, but again, the mould always came back, even on ceramic tiles.
Some folk may mistake black would for damp, and vice versa. But the only solution seems to be, to create adequate ventilation (fresh air circulating) around the problem area.
Hope this helps