Soil | Treatment | K_{m(app)} (μl liter^{−1})^{a} | V_{max(app)} (pmol g^{−1} h^{−1}) | First-order rate constant (h^{−1})^{b} | % Inhibition compared to^{c}: | Implied inhibition mechanism | Curve fit (R^{2})^{d} | ||
---|---|---|---|---|---|---|---|---|---|

True | Pseudo | H_{2}O | K^{+} | ||||||

Birch taiga | H_{2}O | 0.00711 | 0.994 | ||||||

K_{2}SO_{4}
| 0.00653 | 8.2 | ? | 0.996 | |||||

(NH_{4})_{2}SO_{4}
| 0.00526 | 26^{*}
| 19^{*}
| ? | 0.992 | ||||

KCl | 0.00078 | 89^{*}
| ? | 0.772 | |||||

NH_{4}Cl | 0.00072 | 90^{*}
| 7.7 | ? | 0.771 | ||||

Temperate hardwood | H_{2}O | 15.2 (1.3) | 5,807 (329) | 0.705 | 0.998 | ||||

K_{2}SO_{4}
| 9.8 (0.4) | 2,662 (584) | 0.510 | 28^{*}
| Uncompetitive | 0.999 | |||

(NH_{4})_{2}SO_{4}
| 22.4 (1.8) | 2,870 (157) | 0.235 | 67^{*}
| 54^{*}
| Mixed competitive | 0.998 | ||

KCl | 7.2 (0.6) | 786 (30) | 0.200 | 72^{*}
| Uncompetitive | 0.993 | |||

NH_{4}Cl | 25.6 (4.9) | 1,174 (155) | 0.085 | 88^{*}
| 58^{*}
| Mixed competitive | 0.991 | ||

Temperate pine | H_{2}O | 6.7 (0.9) | 2,594 (160) | 0.715 | 0.984 | ||||

K_{2}SO_{4}
| 6.1 (0.9) | 1,591 (98) | 0.485 | 32^{*}
| Noncompetitive | 0.978 | |||

(NH_{4})_{2}SO_{4}
| 9.8 (1.4) | 1,699 (123) | 0.320 | 55^{*}
| 34^{*}
| Mixed competitive | 0.986 | ||

KCl | 8.8 (4.0) | 573 (123) | 0.120 | 83^{*}
| Noncompetitive | 0.855 | |||

NH_{4}Cl | 10.9 (7.2) | 515 (176) | 0.085 | 88 | 29 | Mixed competitive | 0.769 |

↵a The values in parentheses are standard errors.

↵b True first-order rate constants were calculated by linear regression of CH

_{4}oxidation rates against midpoint CH_{4}concentrations. Pseudo-first-order rate constants were calculated by determining V_{max}/K_{m}after K_{m}values were converted to picomoles of CH_{4}per bottle.↵c An asterisk indicates that the treatment value was statistically different from the corresponding control value (P ≤ 0.05).

↵d The regression coefficients are linear for the birch taiga soil and nonlinear (Michaelis-Menten curve fit) for the two temperate soils.