Few studies have been done on the fermentation of Carnobacterium maltaromaticum, despite its interesting technological properties for use in time-temperature integrators or bacteriocin production. Our objective was to study the impact of growth under extreme pH on the physiological state of C. maltaromaticum concentrates, as well as reveal resulting cellular stress responses. C. maltaromaticum CNCM I-3298 cells were grown at three different pH values: their optimal pH (pH 7) and two extreme values (pH 6 and pH 9). Viability and acidification activity of obtained concentrates were then measured before and after freezing and freeze-drying. The cell's intracellular pH values and membrane fatty acid compositions were measured. Lipid membrane behavior during cooling, as well as biochemical composition were investigated in native conditions, by FTIR spectroscopy. pH stress induced acidification activity modulations after fermentation, but no impact was observed on cellular resistance to freezing and freeze-drying. Cells maintained their intracellular pH but presented different membrane behaviors during cooling: cells grown under pH stress notably showed distinct lipid transition profiles as well as polar head group behavior to those grown at their optimal pH. The differences in membrane behavior during cooling did not impact resistance to freezing or freeze-drying, suggesting the involvement of additional cellular components. Further data treatment is underway to investigate the role of proteins and polysaccharides of the cell wall, on the bacterial stress responses revealed in this study.