Cladisporum Resinae was certainly the name given to me about the black gunge which caused leaks in the tanks of an aircraft operated in Saudi re-fueled from a little used fuel tanker in Al-Jouf then unflown for a month. Apparently likes tank sealent and after a while will cause corrosion of the tank.
Prist ( anti ice/microbe concentrations were said to be possibly low and or insufficiently dissipated during the re-fuelling allowing the organism to gain a hold in water droplets inside the tank either brought in with the fuel or from condensation with the tanks over the inactive period.
Tank flushing with Biobor another fuel antimicrobiological agent was not an approved cure for this particular make so the alternative cure of flushing the tanks with industrial(methyl) alcohol, not available in Saudi, was carried out at maint base in Switzerland. Crew resorted to a similar treatment with the ethyl varient. Both effacious. Capacitence fuel probes luckily seemingly uneffected.