الملخص

The present study involved the isolation and diagnosis of  molds and yeasts which affecting the local and imported citrus fruits available in the local markets of the Mosul. These fruits include (grapefruit, oranges, lemons, sweet limes, oranges Japanese, sour, bitter orange and  tangerine) .45 isolates were obtained from filamentous fungi and 26 isolates also were obtained from yeasts.The fungi were identified morphogically and microscopically based on Pitt and Hocking taxonomic index(2009) . The molds samples were distributed to the following species Penicillium, Aspergillus, Cladosporium, Mucor, Alternaria, Trichoderma, Fusarium, Rhizopus. The two genera Aspergillus and Penicillium  were identified to the species level, because of their frequent ocurrence in the isolates, as well as the yeasts were diagnosed morphogically and microscopically, their growth have been studied  on  the differential medium.The  system Vitek 2 Compact also has been used .Distinction was made between Basidiomycetes and Ascomycetes yeasts.  yeasts samples were  distributed to 5 genera.They are Crptococcus spp, Candida spp, Saccharomyces spp,, Rhodotorula mucillaginosa, and Geotrichum candidum.The present study included the use of  Candida guilliermondii (which has been isolated during the present study), yeast as biological  control  for the isolated yeast of the present study. The yeast showed high efficiently in inhibiting molds growth specially   P. italicum and A. niger , the yeast inhibited their growth completely and it was 100% .