17.4 Chemically and enzymatically modified
sophoroselipids
The yeastsCandida (Torulopsis) bombicolaATCC 22214 andCandida (Torulopsis)
apicolaIMET 43747 secrete high amounts of sophorolipids (sophoro (se) lipids)
(Table 8). These glycolipids (Figure 6) always contain the disaccharide sophorose
glycosidically linked to (un-) saturated [x]- or [x-1]- hydroxy C 18 or C 16 fatty acids.
Examinations have revealed that at least 14 structurally different sophorolipids are
produced (Tulloch et al., 1968; Asmer et al., 1988; Weber et al., 1990; Davila et al.,
1993).
The native sophorolipids are predominantly acetylated at C6’and C6“(Asmer et
al., 1988). Both, acidic-SL and lactonic-SL, are always present in native culture
suspensions ofCandida bombicola, and can be obtained in concentrations up to
422 g L–1(Table 8). If alkanes, fatty acids or triglycerides are used as sub-
strates, then a carboxylic group is always connected to the end of the lipid moi-
380 17 Enzymatic Synthesis and Modification of Glycolipids
Figure 6. Principal molecular structures of sophorolipids (SL). Top: acidic-SL; Right: lactonic-SL. For
example, using glucose and rapeseed oil as substrates, the following sophorolipid is predominantly se-
creted (see also Table 8): R 1 ¼R 2 ¼acetyl, R 3 ¼methyl, R 4 ¼H, X 2 ,m¼6, n¼7, 17-L-([2’-O-b-D-
glucopyranosyl-b-D-glucopyranosyl]-oxy)-cis-9-octadecenoic-1’,4“-lactone-6’,6“-diacetate.