mould on sealant

[lancenotalot]

I tiled a bathroom about a year ago and used a sanitary silicon sealant around the edges of the showerbath.There are some black patches of mould on some of the sealant around the shower end,I wondered if there is a better (brand of) sealant which is more resistant to this happening and also any way of avoiding this,the bathroom does appear to have quite a bit of moisture in it.
I tiled a second bathroom in the same house and the sealant in that bathroom is still as good as when applied Im assuming the mould is not helped by the bathroom being used by their son who never wipes anything down after use,I am going to remove the affected sealant and replace.

 

[roboughton]

I have used the unibond one with good results, but if its never cleaned down once its stained thats it IMO, strip it out and do it again. But i am only a DIY'er/landlord so i may be way off. If the room is moist this is not helping either so is there any way to extract the moisture?