Mixed culture engineering for steering starter functionality

Promotie

Mixed culture engineering for steering starter functionality

Promovendus mr. M (Maciek) Spuś MSc
Promotor prof.dr. EJ (Eddy) Smid
Copromotor prof.dr. T (Tjakko) Abee
Organisatie Wageningen University, Food Microbiology Laboratory
Datum

vr 2 september 2016

Locatie Aula, gebouwnummer 362
Generaal Foulkesweg 1
362
6703 BG Wageningen
0317-483592

Samenvatting

This study deals with steering and controlling bacterial starter culture performance in Gouda-type cheese production. Performance of defined starter cultures is sometimes negatively impacted by bacterial viruses (bacteriophages) predating on the starter bacteria hindering acidification. Notably, very little is known about the impact of phages on performance of complex undefined mixed starter cultures, and therefore the interaction between bacteria and their phages is broadly addressed throughout the work described in this thesis. Sequential propagation of the starter cultures in milk was used to investigate the possible positive role of bacteriophage predation in ecology of starter cultures and its impact on starter functionality. Most importantly, phage predation plays an important role in stabilizing starter culture’s composition and functionality. The knowledge gained in this study on microbial interactions in starter community, its response to phage predation as well as to environmental conditions changes, is crucial for a rational design of new robust multi-strain starters.