1 research outputs found
Impact of aerobic and respirative life-style on Lactobacillus casei N87 proteome
Lactic acid bacteria (LAB) are used as starter, adjunct and/or probiotic cultures in fermented foods. Several
species are recognized as oxygen-tolerant anaerobes, and aerobic and respiratory cultivations may provide them
with physiological and technological benefits.
In this light, mechanisms involved in the adaptation to aerobic and respiratory (supplementation with heme
and menaquinone) growth conditions of the O2-tolerant strain Lactobacillus casei N87 were investigated by
proteomics. In fact, in this bacterial strain, respiration induced an increase in biomass yield and robustness to
oxidative, long-term starvation and freeze-drying stresses, while high concentrations of dissolved O2 (dO2 60%)
negatively affected its growth and cell survival.
Proteomic results well paralleled with physiological and metabolic features and clearly showed that aerobic
life-style led to a higher abundance of several proteins involved in carbohydrate metabolism and stress response
mechanisms and, concurrently, impaired the biosynthesis of proteins involved in nucleic acid formation and
translation processes, thus providing evidence at molecular level of the significant damage to L.casei N87 fitness.
On the contrary, the activation of respiratory pathways due to heme and menaquinone supplementation, led to a
decreased amount of chaperones and other stress related proteins. These findings confirmed that respiration
reduced oxidative stress condition, allowing to positively modulate the central carbohydrate and energy metabolism
and improve growth and stress tolerance features.
Results of this study could be potentially functional to develop competitive adjunct and probiotic cultures
effectively focused on the improvement of quality of fermented foods and the promotion of human health