RETRACTED: Isolation and Identification of Fungi from Egyptian Ras Cheese Made with some Probiotic Lactobacillus spp. with Reference to Their Toxins and Enzymes

Abstract

Isolation and identification of spoiled fungal species in Ras cheese made by adding probiotic Lactobacillus spp. as adjunct culture were investigated in fresh and 90 days stored samples. Aspergillus flavus and Aspergillus niger were the most predominant spices and have the highest percentages, while they showed lower percentages in the treated cheese samples. However cheese samples were completely free of mycotoxins, A. flavus spices had the ability to produce aflatoxin B1 and G1, and A. niger had the ability to produce Ochratoxin A. All tested A. flavus and A. niger isolates (28) had the ability to produce lipase and protease enzymes; from which 17 and 9 isolates possessed high activities, respectively. The results suggest that incorporation of probiotic bacteria in the manufacture of Ras cheese reduced the fungal growth in cheese, however, some isolated species considered dangerous because its production of toxins and enzymes in proportions affecting the product.