Inactivation of Escherichia coli in soil by solarization |
| |
Authors: | Shengjin WU Motoki NISHIHARA Yoshie KAWASAKI Akitoshi YOKOYAMA Kei MATSUURA Tomohiro KOGA Daisuke UENO Koichi INOUE Takashi SOMEYA |
| |
Institution: | Division of Soil Environment, Faculty of Agriculture, Saga University, Saga 840-8502,;The United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, and;Division of Soil Science, Miyazaki Agricultural Research Institute, Sadowara-chou, Miyazaki 880-0212, Japan |
| |
Abstract: | Contamination of agricultural soil by fecal pathogenic bacteria poses a potential risk of infection to humans. For the biosafety control of field soil, soil solarization in an upland field was examined to determine the efficiency of solarization on the inactivation of Escherichia coli inoculated into soil as a model microorganism for human pathogenic bacteria. Soil solarization, carried out by sprinkling water and covering the soil surface with thin plastic sheets, greatly increased the soil temperature. The daily average temperature of the solarized soil was 4–10°C higher than that of the non-solarized soil and fluctuated between 31 and 38°C. The daily highest temperature reached more than 40°C for 8 days in total in the solarized soil during the second and third weeks of the experiment. Escherichia coli in the solarized soil became undetectable (< 0.08 c.f.u. g?1 dry soil) within 4 weeks as a result, whereas E. coli survived for more than 6 weeks in the non-solarized soil. Soil solarization, however, had little influence on the total direct count and total viable count of bacteria in the soil. These results indicate that soil solarization would be useful for the biosafety control of soil contaminated by human pathogens via immature compost or animal feces. |
| |
Keywords: | biosafety Escherichia coli manure soil solarization |
|
|