Award details

The response of Lactococcus lactis to reducing environmental conditions

Reference	BBS/E/F/00042380
Principal Investigator / Supervisor	Dr Claire Shearman
Co-Investigators / Co-Supervisors
Institution	Quadram Institute Bioscience
Department	Quadram Institute Bioscience Department
Funding type	Research
Value (£)	53,570
Status	Completed
Type	Institute Project
Start date	18/10/2006
End date	17/10/2007
Duration	12 months

Abstract

Lactococcus is a commercially important microorganism used widely in the dairy industry. Cheese quality depends on raw material, starter cultures and fermentation conditions (temperature, humidity, NaCl and pH). Redox potential has an important role in the final properties of fermented dairy products, especially their aroma. One possible explanation is the observed effect of redox potential on amino acid catabolism. The improvement of Lactococcus for industrial purposes involves identifying and controlling the global regulatory circuits responsible for environmental stress response. All bacteria in aerobic environments encounter the adverse effects of oxygen and oxidative stress. The balance between oxidative and non-oxidative states is important for many metabolic reactions. Toxic radicals formed by oxygen cause cellular damage and can result in cell death or delayed growth. Lactococcus lactis is known for its powerful reducing activity in milk which occurs before acidification. But little is known about what these activities are and how they are controlled. Our hypothesis is that the acidification kinetics and growth can be altered by manipulating the environmental redox potential. We will investigate this by separating the effects of oxidation stress produced by oxygen from those produced specifically by redox potential. Environmental stress response is a complex process that can only be addressed by a genome-wide search for the individual but interlinked components. This project will combine physiology, biochemistry, molecular genetics and transcriptome analysis. It will result in new information on redox regulated genes in Lactococcus lactis. This knowledge will increase our ability to control milk and cheese fermentation processes resulting in more efficient and consistent production of high quality dairy foods with improved organoleptic properties.

Summary

unavailable

Committee	Closed Committee - Agri-food (AF)
Research Topics	X – not assigned to a current Research Topic
Research Priority	X – Research Priority information not available
Research Initiative	X - not in an Initiative
Funding Scheme	X – not Funded via a specific Funding Scheme

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