Bacterial Bioindicators in Shirood River in Mazandaran Province

Background and Bioindicators are microorganisms directly associated with environmental changes which their numbers are affected by chemical pollutants. Sampling was done from four stations in Shirood River in depth of 20 cm of water surface and transferred to laboratory in less than 24 hr. KF medium, SPS, ECC Chrome agar, Plate count agar were used for isolation of fecal streptococci, sulfate-reducing bacteria, E. coli, coliform and heterotrophic bacteria, respectively. The mean count of TVC, fecal streptococci, coliform, E. coli, sulfate-reducing bacteria, in four stations in shirood river were 6.78×105, 9.7×104, 1.07×106, 1.27×106 (cfu/1ml); 6×101, 3.65×102, 5.83×102, 1.6×102 (fecal streptococci); 3.58×103, 3.54×103, 2.11×103, 4.42×103 (coliform); 2.51×102, 6.81×102, 1.95×102, 3.62×102 (E. coli); 3.21×102, 2.62×102, 2.25×102, 2.04×101 (sulfate-reducing bacteria). The results of this study showed that the rate of pollution in the studied stations was higher than the standard limits. Other studies also indicate that distribution of some bacterial bioindicators such as coliform and fecal coli forms is very high in site of effluent of domestic and urban sewage.