Dairy processing provides many abiotic stress conditions that change the phenotypic response of lactic acid bacteria (LAB) during fermentation and storage. Genome sequencing of LAB is expanding and leading to significant opportunities to establish specific genetic mechanisms that lead to single and multiple stress responses that underpin the physiological changes. Response differentiation between closely related LAB is linked to a handful of genetic regulatory elements that cascade into hundreds of changes in structure and metabolism of the cell. Determination of the conservation of the regulatory molecule that mediates stress responses provides insights into the mechanisms leading to the various metabolic and cellular responses produced during dairy processing across various strains and provides a basis for predicting the variation of stress response. Although LAB have a somewhat small genome, the capability to respond to stress is clearly fully functional. Among the stringent and the SOS responses of regulatory elements there exist some lead to stress mitigation via expression of a myriad of metabolic changes useful for repairing DNA, neutralizing acid, and producing energy from proteins amino acids and production of new flavor-active metabolites. In addition, lactococci have a small number of unique genes (i.e., cept, codY,. Z) that provide additional survival capabilities through metabolism of protein and induce the industrially-import responses. In the postgenomics era, simultaneous measurement of the cellular phenotype and the metabolomic, proteomic, and genomic mechanism promises to provide a systemwide picture of the intricate molecular dance induced by stresses during dairy processing. This picture has the potential to provide new methods for strain selection and processing changes to direct the survival and metabolism of LAB to achieve new metabolic products in dairy products.
|Original language||English (US)|
|Title of host publication||Encyclopedia of Dairy Sciences|
|Subtitle of host publication||Second Edition|
|Number of pages||11|
|State||Published - Jan 1 2011|
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)