Regulation of CcpA on the growth and organic acid production characteristics of ruminal Streptococcus bovis at different pH

Table 2 The maximum specific growth rate and lag phase of wild-type strain and ccpA-knockout strain of S. bovis S1 at different pH based on the prediction from logistic function (n = 3)

Items¹	Wild-type strain		ccpA-knockout strain		SEM²	P-value³
Items¹	pH 6.5	pH 5.5	pH 6.5	pH 5.5	SEM²	Strain	pH	Strain×pH
μ_max	2.37^a	1.58^b	1.77^b	1.29^c	0.122	< 0.001	< 0.001	0.032
λ	0.74^c	0.88^c	1.17^b	1.82^a	0.128	< 0.001	< 0.001	0.002

¹ μ_max means the maximum specific growth rate (h⁻¹); λ means the growth lag period (h)
² SEM, standard error of mean
³ Strain, strain effect; pH, pH effect; Strain × pH, the interaction between strain and pH
^a,b,c Means within a row with different superscripts differ significantly (P < 0.05)

ISSN: 1471-2180