| Autor: |
Jackson, N. E., Corey, John C., Frederick, L. R., Picken, J. C. |
| Zdroj: |
Soil Science Society of America Journal; July 1967, Vol. 31 Issue: 4 p491-494, 4p |
| Abstrakt: |
Thirty‐gram soil samples, in plastic tissue culture dishes (60 × 15 mm), were irradiated with gamma rays (8000 curie Co‐60 source) at doses ranging from 0 to 3 million rads. Fungal and bacterial plus actinomycetal counts were made by plating soil suspensions on rose bengal‐streptomycin agar and egg albumin agar, respectively. Plates were incubated for 4 to 8 days before counting. The numbers of fungal and bacterial units reflected differences in survival among the microbial populations from soil samples taken at three horizons within field profiles. Microbial counts in the soils at 30% water content (by weight) were generally reduced to zero at lower radiation doses than those in the air‐dry soils. One million rads were required to kill all fungi, but 2 to 3 million rads were required to kill all bacteria in a 30‐g soil sample. At a given water content, samples with the higher initial microbial populations required greater radiation doses for sterilization than samples with lower populations. For small soil samples, exposure to gamma radiation proved a rapid and efficient method of sterilization. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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