Growth rate of rhizosphere bacteria measured directly by the tritiated thymidine incorporation technique
Research output: Contribution to journal › Journal article › Research › peer-review
Standard
Growth rate of rhizosphere bacteria measured directly by the tritiated thymidine incorporation technique. / Christensen, Henrik; Funck-Jensen, Dan; Kjøller, Annelise.
In: Soil Biology and Biochemistry, Vol. 21, No. 1, 1989, p. 113-117.Research output: Contribution to journal › Journal article › Research › peer-review
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Growth rate of rhizosphere bacteria measured directly by the tritiated thymidine incorporation technique
AU - Christensen, Henrik
AU - Funck-Jensen, Dan
AU - Kjøller, Annelise
PY - 1989
Y1 - 1989
N2 - Application of the tritiated-thymidine method for measurement of the in situ cell formation rate of rhizosphere bacteria was investigated. The growth of bacteria was observed in a sterilized soil-plant system. Viable or freeze-killed sterilized sugar beet seeds were coated with a strain of a fluorescent Pseudomonas and grown for 2-4 days in pots with sterilized soil. The pots were incubated with tritiated thymidine, the DNA extracted, and the amount of 3H in DNA measured, and quantified as number of bacteria formed per unit time. On the basis of the incorporation rate of tritiated thymidine and plate counts, specific growth rates were calculated. By use of the tritiated-thymidine method, a growth rate of 4.9 × 104 cells h-1 cm root-1 was obtained (generation time 106 h). Growth rates might be underestimated if thymidine is present in high concentrations in the soil or rhizosphere. Bacteria in the rhizosphere were responsible for 70% of the total bacterial growth in the pots. No significant 3H-labelling of plant root DNA was observed.
AB - Application of the tritiated-thymidine method for measurement of the in situ cell formation rate of rhizosphere bacteria was investigated. The growth of bacteria was observed in a sterilized soil-plant system. Viable or freeze-killed sterilized sugar beet seeds were coated with a strain of a fluorescent Pseudomonas and grown for 2-4 days in pots with sterilized soil. The pots were incubated with tritiated thymidine, the DNA extracted, and the amount of 3H in DNA measured, and quantified as number of bacteria formed per unit time. On the basis of the incorporation rate of tritiated thymidine and plate counts, specific growth rates were calculated. By use of the tritiated-thymidine method, a growth rate of 4.9 × 104 cells h-1 cm root-1 was obtained (generation time 106 h). Growth rates might be underestimated if thymidine is present in high concentrations in the soil or rhizosphere. Bacteria in the rhizosphere were responsible for 70% of the total bacterial growth in the pots. No significant 3H-labelling of plant root DNA was observed.
U2 - 10.1016/0038-0717(89)90019-9
DO - 10.1016/0038-0717(89)90019-9
M3 - Journal article
AN - SCOPUS:38249022720
VL - 21
SP - 113
EP - 117
JO - Soil Biology & Biochemistry
JF - Soil Biology & Biochemistry
SN - 0038-0717
IS - 1
ER -
ID: 224286834