Table 6.

Antibacterial spectrum of rhamnolipid mixtures produced by Pseudomonas strains.

	MIC of rhamnolipid mixtures ( µ g/ml)
	8H	CHA	PA14	4014	Commercial mixture
A. hydrophila LMG 2844	-	-	-	-	-
B. subtilis AM1	41.2	80	26.3	100	-
E. faecalis V583	41.2	-	-	-	-
E. coli DH5Y	20.6	-	-	-	-
F. breve LMG 4011	82.5	-	-	-	-
K. pneumoniae 050283	165	-	-	-	-
L. bozemanii ATCC 33217	0.2	6.2	1.6	5.2	7.8
L. dumoffii ATCC 33279	0.4	12.5	0.4	5.2	15.6
L. feeleii ATCC 35072	0.2	6.2	0.4	3.9	11.7
L. longbeachae ATCC 33484	0.4	12.5	3.3	7.9	13.1
L. micdadei ATCC 33218	0.03	3.1	3.3	3.9	15.6
L. pneumophila ATCC 33155 (Sg 3)	0.2	12.5	3.3	15.8	8.8
L. pneumophila ATCC 33215 (Sg 6)	0.2	6.2	0.4	7.9	3.9
L. pneumophila ATCC 33216 (Sg5)	0.05	25	1.6	7.9	19.5
L. pneumophila ATCC Baa74 130b	0.05	12.5	0.4	7.9	15.6
L. pneumophila Corby (Sg1)	0.2	12.5	3.3	5.2	11.7
L. pneumophila Lens CIP 108286 (Sg1)	0.4	12.5	1.6	10.5	11.7
L. ivanovii Li4pVS2	41.2	-	-	-	-
L. monocytogenes EGDe ATCC BAA-679	41.2	-	-	-	-
P. aeruginosa LMG 1242	-	-	-	-	-
P. aeruginosa PA14	82.5	-	-	-	-
S. enterica J18	82.5	-	-	-	-
S. aureus ATCC 29213	-	805	52.5	50	-

-: no growth of inhibition was detected even with undiluted rhamnolipid mixture (660 µg/ml for the 8H mixture, 1610 µg/ml for the CHA extract, 105 µg/ml for the PA14 extract, 100 µg/ml for the 4014 extract, and 250 µg/ml for the commercial mixture).

Bacteria (10⁶ CFU/ml) were incubated in BYE or BHI medium with two-fold dilutions of rhamnolipid mixtures. Results correspond to the MIC after incubation for 24h or 96 h at 37°C depending on the tested strain and are the mean of three independent experiments.

Bacterial strains were obtained from various culture collections: ATCC: American Type Culture Collection, CIP: Collection Institut Pasteur, France, and LMG: BCCM/LMG Bacteria Collection, Ghent University, Belgium. The Corby strain was kindly provided by the Centre National de Référence des Légionelles (Lyon, France). Other strains were from the laboratory culture collection. Sg: serogroup.