Mycobiota and ochratoxigenic black Aspergilli associated with dried seeds of sumac (Rhus coriaria L.) growing in Iraq

Seeds and powder of sumac (Rhus coriaria L.) is well known spice and has been utilized by indigenous people at Kurdistan region of Iraq in many popular meals as well as in many medicinal purposes. The mycobiota of twelve sumac seed samples was examined after surface disinfection with sodium hypochlorite and plating on Dichloran Rose Bengal Chloramphenicol (DRBC) medium. Fungi were isolated and identified to species level and percentage contamination levels by fungi were calculated. The species of genera Apergillus Mich ex Fr. and Penicillium Link were the most frequently isolated fungal species from sumac seeds. The other genera included Eurotium Link ex Fr., Monilia Pers ex Fr., Neocytalidium Crous & slippers, Rhizopus Ehrenb, Sclerocleista Subram, Trichoderma Pers ex Fr. and Ulocladium Preuss. The highest isolation frequency was displayed by the genera Aspergillus and Penicillium (100%) followed by Rhizopus (50%). The broadest species spectrum was found in the genera Aspergillus and Penicillium which were represented by 8 and 5 species respectively. Among eight species of Aspergillus, 4 species were identified in Aspergillus section Nigri. These include A. carbonarius, A. foetidus, A. niger and A. tubingensis. The most common species isolated were A. niger and A. flavus with a colonization percentage of 31.4 and 13.33% respectively. Among the predominant species of Penicillium, P. camemberti and P. glabrum with 9.33% and 5.0% iolation percentage respectively. Ochratoxigenic producing potential of two isolates of A. carbonarius was confirmed using ELISA method. Levels of ohratoxin A (OTA) produced by the two isolates on yeast extract sucrose agar ranged from 0.3-0.64 ng/g. Our study indicates possible hazards for humans upon consumption of sumac contaminated seeds by toxigenic moulds.