Abstract
Some of fungi can live in scarce food and called oligotrophes. Water of household tanks provides a perfect environment especially those reservoirs that are not cleaned regularly. In Al-Hassa, Saudi Arabia, the water enter from the municipal to the tanks in every home-based system. There are two tanks in every home, the first one is inside the house on the ground floor, and the second is on the top surface of the building. A motor lifting water from the lower reservoir to the upper reservoir, which in turn distributes the water to each water inlet. In Saudi Arabia, there is no enough studies concerning fungi found in household tank water. This research aims to Shed light on the existence of a certain types of fungi in household water tanks in the city of Hofuf, Al-Hassa, Saudi Arabia. Filamentous fungi were isolated from 15 of 15 (100%) samples, yeasts from 14 (93%) and both from 14 (93%) water samples. The mean number of colony-forming units of filamentous fungi was 20-57 and of yeasts 7-16. Prevailing species were Candida parapsilosis and Candida guilliermondii each isolated from 12 samples (80%), Phialophora verrucosa from 11 samples (73.3%), each of Aspergillus niger, Candida tropicalis and Rhodotorula mucilaginosa from 10 samples (66.7%), Penicillium chrysogenum from 8 samples (53.3%), Sterile mycelium A from 7 samples (46.7%), each of Cladosporium cladosporioides and Penicillium citrinum from 6 samples (40%), each of Mucor mucedo, Mucor mucedo and Penicillium nigricans from 5 samples (33.3%), Acremonium strictum from 4 samples (26.7%), each of Acremonium alabamensis, Alternaria alternate, Stachybotrys chartarum and Sterile mycelium B from 3 samples (20%), and Sterile mycelium C from 2 samples (13.3%).