Growth, dormancy and lysis: the complex relation of starter culture physiology and cheese flavour formation

Fast acidification and growth are desired from lactic acid bacteria starter cultures during food fermentation to minimise the risk of spoilage and process failure. In addition, starter cultures play a predominant role in the formation of flavour volatiles. Recent studies in different microbial species have shown that high growth rates come at the expense of the expression level of metabolic enzymes and/or stress proteins. In starter cultures, such a trade-off would affect flavour formation, which depends on the level of flavour-forming enzymes and the prolonged survival of cells. Moreover, starter culture performance during cheese ripening could also be influenced by its cultivation history due to the low number of divisions during cheese manufacturing and limited proteome adjustment during ripening. These findings indicate that changes in (pre)-culture conditions can modulate proteome allocation and metabolic stability in starter cultures, and thereby provide novel approaches to steer flavour formation.