Particle attached and free floating pathogens survival kinetics under typical stream and thermal spring temperature conditions

AMB Express

Table 1 Kinetics of E. coli O157:H7 and Salmonella survival in free-floating and particle-attached conditions in stream water (time is in minute)

Temp. (°C)	E. coli O157:H7		Salmonella
Temp. (°C)	Free-floating	Particle attached	Free-floating	Particle attached
	Equations of decay curves²
30	^ay = − 0.00066 × (time) + C₀	^ay = − 0.00065 × (time) + C0	^ay = − 0.00055 × (time) + C0	^ay = − 0.00062 × (time) + C0
40	^by = − 0.00062 × (time) + C0	^by = − 0.00044 × (time) + C0	^by = − 0.00052 × (time) + C0	^by = − 0.00072 × (time) + C0
50	^cy = − 0.01448 × (time) + C0	^dy = − 0.00308 × (time) + C0	^ey = − 0.02000 × (time) + C0	^fy = − 0.00454 × (time) + C0
60	^gy = − 0.09910 × (time) + C0	^hy = − 0.08188 × (time) + C0	ⁱy = − 0.10908 × (time) + C0	^jy = − 0.04308 × (time) + C0
	First order rate constant [k]³ (min⁻¹)
^a30	0.00152	0.00150	0.00128	0.00143
^b40	0.00143	0.00092	0.00120	0.00165
^c50	0.03334	0.00709	0.04606	0.01044
^d60	0.22822	0.18857	0.25120	0.09920
	Z-value⁴
	9.14746	8.65426	8.30772	11.32888

Different letters in subscript of regression equations shows the line is significantly different at p < 0.05
Similar letters in subscript of z-values show the values are not significantly different at p < 0.05
Different letters in subscript of k-values show that these values were significantly different among temperature at p < 0.05
¹C₀ = initial pathogen concentration (CFU/mL)
²R² values for decay curve varied between 0.75 and 0.99
³Rate constant (k) was estimated from D-values (k = 2.303/D)
⁴The Z-values were estimated based on slope (i.e., z-value = − 1/(slope between temperature and D-value)