ABSTRACT
The brown slime inside pipeline of the polluted mineral waters well was analyzed. It was confirmed that the brown slime was a biofilm formed mainly by growth of bacteria contaminant, using microscope analysis. After treated with HCl, the brown crystals and mycelioid matter presented in slimes disappeared. It was verified these were metal deposits. The samples produced Prussia blue deposits by dropping K 4Fe(CN) 6 and HCl, which proved that the metal deposits were iron compound. Also it was believed the biofilm was produced by growth of iron bacteria, mixed with deposits of iron compound. The iron bacteria have been isolated from the slimes and cultured in the laboratory. The colony on agar plate also produced Prussia blue deposits after treated with K 4Fe(CN) 6 and HCl. The cells form of pure culture was the same as that in the samples by electronmicroscope analysis. Therefore, It indicated that the bacteria on biofilm inside pipeline were iron bacteria mainly.