Table 1.

Enzyme activity in the presence and absence of chloramphenicol and parameters of linear regression equations of enzyme activity versus chloramphenicol concentration

AssaySoilMeasured activity rate (ng of N g dry soil−1 h−1) for chloramphenicol concn (g/liter) of:Regression equation
00.1InterceptSloper2Pa
Net nitrite productionHumisol11.83 (1.46)b 10.64 (2.63)10.13−2.250.5690.005
Humisol 3.68 (0.24) 4.57 (0.33)4.52−1.020.772<0.005
Sandy loam 0.35 (0.08) 0.85 (0.06)0.86−0.110.864<0.005
Nitrite reductionHumisol91.94 (8.23)35.45 (4.07)38.49−5.350.3610.066
Humisol30.68 (2.84)23.61 (5.00)26.742.370.1210.324
Sandy loam 7.74 (1.99) 0.92 (0.67)1.300.060.0020.910
  • a P value for F test of null hypothesis that slope of regression line is 0.

  • b Values in parentheses are standard deviations.