Table 5.

Proportion (% of total intermediates and 18:2n-6) of 18:2n-6 and its biohydrogenation intermediates after 24 h of incubation under different growth conditions^a with different biomass ratios of Butyrivibrio fibrisolvens D1 to Propionibacterium acnes DSM 1897 in the inoculum (Exp. 4)

		B. fibrisolvens (%)/C. acnes (%)						SEM	P-value
		100/0	50/50	10/90	2/98	0.4/99.6	0/100		b	Linearc	Quadraticd
18:2n-6	Control	1.81	2.18	4.76	25.95	16.44	46.67	13.050	R***	<  0.001	0.004
	Low pH	53.91*	60.34*	53.52*	48.95*	51.49*	55.24		M***	0.579	0.320
	DHA	13.28	20.29	38.47*	57.28*	64.67*	75.28*		R × M***	<  0.001	0.014
c9, t11 CLAe	Control	0.20	18.28	14.75	7.78	5.03	<  0.01	7.534	R***	<  0.001	0.004
	Low pH	45.51*	17.59	4.03	0.95	<  0.01	<  0.01		M***	<  0.001	0.563
	DHA	82.52*	70.06*	38.85*	18.20	9.79	<  0.01		R × M***	0.828	0.043
trans-11 18:1	Control	97.93	72.57	57.69	31.88	44.80	0.46	9.460	R**	0.772	0.977
	Low pH	0.57*	0.38*	0.37*	0.44*	0.42*	0.39		M***	0.988	0.990
	DHA	4.11*	2.15*	2.28*	0.74*	2.36*	0.36		R × M***	<  0.001	0.086
t10, c12 CLAf	Control	<  0.01	2.63	8.72	18.98	13.61	53.37	6.606	R***	<  0.001	0.629
	Low pH	<  0.01	21.70*	42.04*	49.66*	48.01*	44.37		M***	<  0.001	0.767
	DHA	<  0.01	8.15	19.97	23.57	21.69	24.29*		R × M**	<  0.001	0.019
trans-10 18:1	Control	0.06	4.34	14.08	15.40	20.11	<  0.01	3.927	R*	0.905	0.943
	Low pH	<  0.01	<  0.01	0.04*	<  0.01*	0.08*	<  0.01		M***	0.992	0.998
	DHA	0.08	<  0.01	0.42*	0.21*	0.90*	0.06		R × M*	<  0.001	0.911
trans-10/trans-11g	Control	–	0.08	0.34	2.46	2.44	–	9.296	R***	0.017	0.082
	Low pH	–	1.22	12.67	65.74*	90.01*	–		M***	<  0.001	<  0.001
	DHA	–	0.10	0.95	2.86	9.74	–		R × M**	<  0.001	0.003

^a Low pH, control medium with pH adjusted to 5.5; DHA (docosahexaenoic acid), control medium containing 40 μg/mL of 22:6n-3; all growth media contained 40 μg/mL of 18:2n-6

^b R, effect of ratio of B. fibrisolvens to C. acnes in the inoculum; M, effect of growth medium; * 0.01 ≤ P < 0.05; ** 0.001 ≤ P < 0.01; *** P < 0.001

^c Linear effect of R within each growth medium

^d Quadratic effect of R within each growth medium

^ec9, t11 CLA, cis-9, trans-11 conjugated linoleic acid

^ft10, c12 CLA, trans-10, cis-12 conjugated linoleic acid

^g Ratio of trans-10 intermediates (trans-10, cis-12 CLA + trans-10 18:1) to trans-11 intermediates (cis-9, trans-11 CLA + trans-11 18:1)

* Means differ (P < 0.05) from the control growth medium within the same ratio

-: The ratio is not relevant for mono-cultures as trans-11 and trans-10 are produced exclusively with mono-cultures of B. fibrisolvens and C. acnes, respectively