Study of fungi in Rajaeii dam laeke water and evaluation of its health quality as drinking water source

Being free from human health risk factors is considered as the most important parameter of drinking water sources.The aim of the present study was quantative evaluation and identification of fungi in water of Shahid Rajaeii dam lake, and assessment of its health quality as drinking water source of Sari (Mazandaran province).
In the present study, samples were taken from five stations in six stages from June to February 2012. Every sample was diluted by sterile saline (100 and 10-1) and was cultured on SD and incubated at 27-30°C for 3-5 days. Finally, the number of colonies was recorded as Colony Forming Unit (CFU) per 100 mL. Also, teamperature, BOD5 and COD were measured.
The results showed that the numbers of isolated fungal colonies were significantly highest and lowest in August and February respectively. Moreover, the number of fungal colonies in the dam crown station was significantly higher than other stations. The correlation coefficient between the number of isolated colonies and the temperature, BOD5 and COD were 0.87, 0.60 and 0.66 respectively. The frequency of identified fungi were Aspergillus species (31.4%), various types of yeast (mainly Candida) (24.2%), Penicillium sp. (19.3%), Cladosporium sp.(10.3%), Mucor sp. (5.4%), Fusarium sp. (2.9%), sterile hype (2.8%), Alternaria sp. (2.3%) and Paecilomyces sp. (1.4%).
Summery: The results showed the highest correlation coefficient between the counts of fungi and the changes in temperature, BOD5 and COD correspondingly. These factors play an important role in the fungal colonies counts. Moreover, the most fungal isolates were pathogenic, toxigenic and hazard to public health.