Effect of cold temperature on the composition of different lipid classes of the foodborne pathogen Listeria monocytogenes: Focus on neutral lipids
2006
Mastronicolis, S.K. | Boura, A. | Karaliota, A. | Magiatis, P. | Arvanitis, N. | Litos, C. | Tsakirakis, A. | Paraskevas, P. | Moustaka, H. | Heropoulos, G.
In this work a thorough consideration of the membrane lipid composition of Listeria monocytogenes together with DSC analysis is described in order to estimate the biological importance of lipid changes during low-temperature adaptation. Furthermore, these studies provide comparative data for fatty acid changes for neutral, NL and polar lipids, PL separately. The cold adaptation (5 °C) response of L. monocytogenes showed (i) an increase in the level of NL content (30%) among the total lipids, TL and (ii) that the increase (7-fold) in the anteiso-15:0/anteiso-17:0 fatty acid ratio, FAr, for cold NL was at variance with the ratio for TL and PL (about 10-fold). We correlated our findings with DSC studies on phase transition temperature (T(c)), enthalpy difference (ΔH) and peak range of the transition for TL, PL, NL (from cultures at 30 and 5 °C); The decrease of T(c) (10.5°C) and ΔH (51%) for TL is a reflection of the decrease of T(c) (11.5°C) and ΔH (56%) for PL. This large decrease is interpreted by the high (10-fold) increase of a-15:0/a-17:0 FAr of PL(5 °C). In NL the decrease of T(c) (3°C) and of ΔH (42%) is interpreted by both adaptation mechanisms: the (lower) 7-fold increase of anteiso-15:0/anteiso-17:0 FAr and the NL percentage calculated from increased mass values. The peak range of TL(5 °)C (from -15 to 25 °C) is a reflection of the peak range of NL(5 °C), which is unchanged, as is the peak range of NL(30 °C).
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