but not fermentation without cold (same
number of CFUs per A600 unit in aerobic and fermentative cultures
at optimal temperature). As cold with fermentation caused an
increase in the CFU size (100 times fewer CFUs per A600 unit than at
optimal temperature), we can conclude that cold and fermentation
increased CFU size synergistically. A synergy of the two conditions
to reduce biomass production was observed by de Sarrau et al.
(2012). Microscopic observation confirmed the variation in CFU
size over the different growth conditions, with cell lengths from
4 mm to at least 170 mm. The formation of long cells in cold
fermentative cultures was observed for two strains and two
different media. In addition, a specific alteration of morphology was
observed in cold aerobic cultures. Light microscopy observations
made by den Besten et al. (2009) during growth of B. cereus in salt
stress conditions permitted to see the individual cells forming the
filaments. In our study, light microscopy did not permit to distinguish
the separated cells