Functional implications of the microbial community structure of undefined mesophilic starter cultures

Abstract

This review describes the recent advances made in the studies of the microbial community of complex and undefined cheese starter cultures. We report on work related to the composition of the cultures at the level of genetic lineages, on the presence and activity of bacteriophages and on the population dynamics during cheese making and during starter culture propagation. Furthermore, the link between starter composition and starter functionality will be discussed. Finally, recent advances in predictive metabolic modelling of the multi-strain cultures will be discussed in the context of microbe-microbe interactions.

Figure 1

Composition of undefined starter Ur. The culture consists of Lactococcus lactis (lineages 1 to 7) and Leuconostoc mesenteroides (lineage 8). Calculation of the composition was based on data taken from [4].

Figure 2

Composition of sequentially propagated original complex starter culture (panel A) and reconstituted defined starter culture (panel B). The cultures were daily propagated in sterile skimmed milk with 1% inoculum for a period 29 days (equivalent to 186 generations) at 20°C. The composition of the cultures at the end-point was measured using lineage specific qPCR primers described in [4]. The colours indicate the genetic lineage and the percentages indicate the measured relative abundance. Data from: De Groof, Wolkers-Rooijackers and Smid, 2013, unpublished results.