Aims: The aim of the study is to gain further insight on the respiratory
behaviour of Lactobacillus plantarum and its consequences on stress tolerance.
Methods and Results: We investigated the effect of temperature and
respiration on the growth and stress (heat, oxidative, freezing, freeze-drying)
response of Lact. plantarum C17 during batch cultivations. Temperature as
well as respiration clearly affected the physiological state of cells, and generally,
cultures grown under respiratory conditions exhibited improved tolerance of
some stresses (heat, oxidative, freezing) compared to those obtained in
anaerobiosis. Our results revealed that the activities in cell-free extracts of the
main enzymes related to aerobic metabolism, POX (pyruvate oxidase) and
NPR (NADH peroxidase), were significantly affected by temperature. POX was
completely inhibited at 37°C, while the activity of NPR slightly increased at
25°C, indicating that in Lact. plantarum, the temperature of growth may be
involved in the activation and modulation of aerobic/respiratory metabolism.
Conclusions: We confirmed that respiration confers robustness to
Lact. plantarum cells, allowing a greater stress tolerance and advantages in the
production of starter and probiotic cultures.
Significance and Impact of the Study: This is the first study on respiratory
metabolism on a strain other than the model strains WCFS1; novel
information on the role of temperature in the modulation of aerobic/
respiratory metabolism in Lact. plantarum is presented