Thesis (M.Sc.) - Cairo University - Faculty of Science - Department of Microbiology

The mycotoxin, patulin (PAT) is produced by a number of fungi common fruit and vegetable based products, most notably apples. Despite patulin{u2019}s original discovery as an antibiotic, it has come under heavy scrutiny for its potential negative health effects. The objective of this study was to investigate efficacy of some probiotic agents such as, kombucha tea, Saccharomyces cerevisiae (baker's yeast) and lactic acid bacteria strains (LAB, Lactobacillus acidophilus, L. bulgaricus, and L. rhamnosus) in controlling fungal growth and PAT production by some fungi infecting fruits and fruit juices. PAT detoxification in aqueous solution, liquid medium and fruit samples using these probiotic species has been applied in this study. Kombucha tea is a refreshing beverage obtained by fermenting sugared tea with a symbiotic culture of acetic acid bacteria and yeast, consumed for its positive effects on human health. Also, cerevisiae and LAB are GRAS (generally recognized as safe) microorganisms that modify the food enhancing quality, and additionally they possess nutritional and therapeutic benefits. They represent unique groups, which are widely used in food fermentation and preservation. In this study, 63 strains of fungal species were isolated from 13 samples of fruits and fruit juices collected locally and randomly from several supermarkets (Giza, Egypt), among of them 16 strains were positive for PAT production. Three fungal strains pPenicillium expansum LC015096, Talaromyces purpureogenus LC015095, and Acremonium implicatum LC015097 were selected on the basis of their activity for PAT producing ability to study the physiological behavior of PAT biosynthesis

Issued also as CD