First of all, you need to know the size of the aspores of Byssochlamys fulva. You know already that your ultrafiltration membrane has a MWCO (molecular weight cut-off) of 100 kDalton (=100000 Dalton). Are the aspores bigger or smaller than that?
Only with this information you can estimate if your UF membrane has the role of strerile filtration of your juice.