survey of fungal flora in the water of old and new distribution system in aradan city

One of the great concerns of potable water consumers regarding its quality is the pollution of potable water with pathogenic microorganisms. fungi in drinking water are responsible for changing the taste and odor of water. health problems are possible, originating from mycotoxins, animal pathogens and allergies. water samples were collected between december 2014 and june 2015 from different sites of municipal water supply system of aradan, iran. in this descriptive study, a volume of 100 ml of tap drinking water samples (n = 60) were collected in sterile bottles. all water samples passed through sterile 0.45 micrometer filters. the filters were placed directly on sabouraud dextrose agar and incubated at 20°c for 4-7 days. routine mycological techniques were applied to identify the grown fungi. three dominant fungi genera in water were cladosporium, aspergillus and penicillium, the concentrations [colony forming unit (cfu)/100 ml] of which were higher in old and new water distribution system. among aspergillus species, a. flavus had the highest frequency; from 555 fungal colonies, 11 different fungal genera were identified. various fungi were present in the tap water. present study showed that average concentration of fungi increased in old water distribution.