Biosynthesis of rhamnolipid by a Marinobacter species expands the paradigm of biosurfactant synthesis to a new genus of the marine microflora

Table 2 Composition of rhamnolipid congeners synthesised by Marinobacter sp. MCTG107b

RT min	m/z value	Compound	Mw (Da)	Molecular form	Relative %
Mono-rhamnolipid congeners
14.8	387.22	Rha-C_14:2	386.48	C₂₀H₃₄O₇	3.18
21.5	533.46	Rha-C₁₀-C₁₂/Rha-C₁₂-C₁₀	532.71	C₂₈H₅₂O₉	0.22
24.2	503.47	Rha-C₁₀-C_10:1	502.64	C₂₆H₄₆O₉	0.27
26.9	561.52	Rha-C₁₂-C₁₂/Rha-C₁₀-C₁₄	560.76	C₃₀H₅₆O₉	0.94
Subtotal					4.61
Di-rhamnolipid congeners
4.6	453.27	Rha-Rha-C₈	452.49	C₂₀H₃₆O₁₁	1.95
12.7	480.39	Rha-Rha-C₁₀	480.55	C₂₂H₄₀O₁₁	5.13
22.1	537.45	Rha-Rha-C₁₄	536.65	C₂₆H₄₈O₁₁	0.21
31.0	649.71	Rha-Rha-C₁₀-C_10:1/Rha-Rha-C_10:1-C₁₀	648.74	C₃₂H₅₆O₁₃	2.85
32.1	651.73	Rha-Rha-C₁₀-C₁₀	650.79	C₃₄H₅₈O₁₃	52.45
32.8	677.77	Rha-Rha-C₁₀-C_12:1	676.83	C₃₃H₆₀O₁₃	1.06
33.0	665.77	Rha-Rha-C₁₀-C₁₀-CH₃	664.82	C₄₂H₆₀O₁₃	23.07
34.5	803.54	Decenoyl-Rha-Rha-C₁₀-C_10:1	801.01	C₃₅H₇₂O₁₁	0.40
35.1	679.78	Rha-Rha-C₁₀-C₁₂/Rha-Rha-C₁₂-C₁₀	678.84	C₃₅H₆₄O₁₃	5.01
37.2	693.90	Rha-Rha-C₁₀-C₁₂-CH₃/Rha-Rha-C₁₂-C₁₀-CH₃	692.80	C₃₅H₆₄O₁₃	3.26
Subtotal					95.39

Rhamnolipid congeners were identified via HPLC–MS in SPE purified extracts from cell-free culture supernatant samples obtained after 96 h growth in a bioreactor

ISSN: 1475-2859