TABLE 1.

Carbon substrates utilized by C. jejuni on Biolog plates and reported to be present on root or leaf surfaces

Substrate	Activity in biolog platesa	Root exudatesb	Leaf exudatesb
l-Arabinose	382 ± 33	+	+
l-Fucose	445 ± 41	+c	+c
α-d-Glucose	74 ± 22	+	+
α-Hydroxybutyric acid	871 ± 47	+	NRd
Succinic acid	196 ± 20	+	+
l-Asparagine	300 ± 33	+	+
l-Aspartic acid	231 ± 27	+	+
l-Proline	68 ± 11	+	+
l-Serine	62 ± 21	+	+
l-Cysteinee	1,564 ± 90	+	−

^aC. jejuni strains were assayed for respiration induced by carbon substrates present in GN2 Biolog plates (Biolog, Inc., Hayward, Calif.). The data are presented as the averages ± standard errors of the means of the normalized optical densities for 38 strains of C. jejuni. These strains included isolates from retail chicken liver and carcass samples (n = 14), human clinical isolates representing different heat-labile (Lior; n = 8) and heat-stable (Penner: n = 6) serotypes, and one calf isolate. Each strain was tested at least twice.

^b+ or − indicates whether the compound was detected in soluble root exudates (12, 27) or leaf exudates (13, 33).

^cPresent in plant cell walls (47).

^dNR, not reported to be present.

^el-Cysteine was tested separately as described in Material and Methods.