Diversity of Toxigenic Molds and Mycotoxins Isolated from Dairy Products: Antifungal Activity of Egyptian Marine Algae on Aspergillus and Candida Species

Abstract

Fungal and mycotoxin contamination of milk products constitute a potential hazard to human health and food safety. Isolation and identifications of mold and yeast out of 140 milk products samples collected from dairy shops in Qena, Egypt were done through conventional microbiological methods. Aflatoxin-M1, aflatoxin-B1 and ochratoxin-A were characterized by thin-layer chromatography; aflR regulatory gene identified by using PCR. Marine algal extracts of Halimeda opuntia, Padina pavonica and Turbinaria decurrens species were studied for their antimicrobial activity. Overall of 80 and 64% dairy products samples were positive for mold and yeast contamination. A total of 38 mold and 15 yeast species were isolated. Aspergillus and Candida spp. were the most abundant isolated species. Furthermore 25, 40 and 27% of cheese and 71, 78 and 73.3 of dairy desserts samples were contaminated with AFM1, AFB1 and OTA, respectively; with average estimated dietary intake level much more than the acceptable daily intake for infant and adult. PCR identified aflR gene among four selected aflatoxigenic A. flavus. The major constituents of H. opuntia extract were 2,4-Decadienal, (E,E)-(21.56%) and 9,12-Octadecadienoic acid (Z,Z)-(36.16%). Ethyl acetate extract of Halimeda opuntia (3mg/ml) exhibited the strongest fungicidal activity with inhibition zones of 16.5 and 22.3 mm against A. flavus and A. niger. It exhibited potent candidacidal activity against C. tropicalis; 11 log10 orders of killing at 750 µg/ml. The discovered antimicrobial activity of H. opuntia is a promising candidate for designing novel antifungal agents which can be used in food preservatives and medicine industry.

The Egyptian Ascomycota 1: Genus Aspergillus

“…Moubasher et al (2018b) isolated Aspergillus sp. from Ras cheese, the most common species isolated from surface and core of examined Ras cheese samples were; A. flavus (Zommara and Rashed 2004;ELbagory et al 2014;El-fadaly et al 2015a, b;El-Badry and Raslan 2016;Seddek et al 2016;Elramly et al 2019;Ahmed et al 2020), A. niger (ELbagory et al 2014El-fadaly et al 2015a, b;El-Badry and Raslan 2016;Seddek et al 2016;Younis et al 2016;Elramly et al 2019;Ahmed et al 2020) andA. fumigatus (ELbagory et al 2014;Seddek et al 2016;Younis et al 2016;Elramly et al 2019;Ahmed et al 2020).…”

“…glaucus (El-fadaly et al 2015a, b), A. nidulans (El-fadaly et al 2015a, b;Elramly et al 2019), A. ochraceus (El-fadaly et al 2015aEl-Badry and Raslan 2016;Elramly et al 2019;Ahmed et al 2020), A. oryzae (El-fadaly et al 2015aAhmed et al 2020), A. parasiticus (Zommara and Rashed 2004;El-Badry and Raslan 2016;Younis et al 2016;Ahmed et al 2020), A. sydowii (Ahmed et al 2020), A. terreus (ELbagory et al 2014Embaby et al 2015;Younis et al 2016;Elramly et al 2019) and A. ustus (Seddek et al 2016). Furthermore, Hegazy et al (2014) reported isolation of A.…”

Antifungal Disinfectants Efficiency on Aspergillus Strains From Camel’s Milk and Drinking Water: Biological Detoxification of Aflatoxin-M1

“…Molds can develop in a broad range of pH 2-9, according to the FAO (1992), and can alter the pH of milk to around 4-6.5 to help their development followed by induction of undesirable spoilage changes such as color defects, off-flavor, changes in texture and rancidity (Mislivec et al, 1992). Also, some mold species are considered to be a potential human health and food safety hazard owing to their ability to produce mycotoxins (Ahmed et al, 2020).…”

“…Estimated Daily and Weekly Intakes (EDI and EWI) of the examined samples were obtained according to the equations described before elsewhere (Ahmed et al, 2020;Diab et al, 2020). Moreover, the results were matched to the international standards organization's Acceptable Daily Intake (ADI).…”

“…Fungal contamination of food and water play a significant role in gastrointestinal troubles which negatively impact human health (Ahmed et al, 2020). In water distribution municipal networks and tap water, molds are a mutual member of the flora (Kelley et al, 1997;Paterson and Lima, 2005).…”