See:
http://horttech.ashspublications.org/cgi/content/abstract/19/1/96
Link: horttech.ashspublications.org/cgi/content/abstract/19/1/96
I use slightly dampend coir to stratify my seeds & find very little of the white fungus growing on my seeds. When it does happen it’s sometimes an indication that the seed has rotted from the inside. Coir is also easy to sift through when seeds are stratified in baggies because the coir doesn’t stick to itself.
From what I’ve read about the levels of sodium and phenolic compounds in coir, I’m not even slightly surprised that growth of microorganisms was suppressed.
Unless coir is thoroughly leached or composted and aged (with the same effect, of reducing sodium levels and levels of phenolic compounds), it is not what you should use for your seedlings. Search this forum for users’ comments and for some links to other research.
Commercial planting soil blends which contain coir have presumably been treated to make the coir safe to use. Once treated, coir is a very long lasting medium and can give very good plant growth.
Peter