Diversity and transport of bacteria and viruses in soils following irrigation with recycled water

Abstract

Field and laboratory analyses were conducted to study bacteria and virus transport and diversity in surface soils following irrigation with recycled water. Field test plots were irrigated with R-1 (oxidized, filtered, disinfected) water and tap water, and pan lysimeters were used to collect leachate water samples. R-1, R-2 (oxidized, disinfected), R-3 (oxidized only) and tap water were applied to soil columns. Fecal coliform and coliphage were only found in the leachate from the R-3 soil column. Polymerase chain reaction denaturing gradient gel electrophoresis analysis (PCR-DGGE) of 165 rRNA genes was used to analyze the bacterial population in leachate and soil samples from different depths. The R-1 field test plot had a more diversified bacterial community than a tap water control plot. Surface soils from field test plots had more bacteria species than that of bottom soils. Different DGGE banding profiles were found at different depths in R-1, R-2 and R-3 effluent soil columns. UV dosage did have some effect on soil microbial diversity.