ABSTRACT: Metagenomic Analysis of Dairy Bacteriophages: Extraction Method and Pilot Study on Whey Samples Derived from Using Undefined and Defined Mesophilic Starter Cultures
Project description:Growth of L. cremoris NCDO712 was not altered when manganese is omitted from its defined medium. This study was conducted in order to compare protein requirements of Lactococcus cremoris NCDO712 to grow in the presence or absence of manganese in defined medium (1% lactose). The majority of protein adaptation involves upregulation of Mn transporters and to a lesser extent various NADH-dependent proteins. Such adaptation is highly relevant for starter culture in dairy fermentation where manganese is limited and NADH homeostasis determines the formation of volatiles during long-term incubation e.g. cheese ripening.
Project description:The effect of dietary calcium and dairy proteins on adipose tissue gene expression profile in diet induced obesity Experiment Overall Design: 9-week-old C57Bl/6J-mice were divided into two groups (n=10/group). The control diet was a standard high-fat diet (60% of energy) low in calcium (0.4%). The whey protein diet was a high-calcium (1.8%) high-fat diet with whey protein isolate. After the 21-week treatment, the adipose tissue transcript profiling (2 mice/group) was carried out using Affymetrix Mouse Genome 430 2.0 array.
Project description:Lactobacillus helveticus is a rod-shaped lactic acid bacterium that is widely used in the manufacture of fermented dairy foods and for production of bioactive peptides from milk proteins. Although L. helveticus is commonly associated with milk environments, phylogenetic studies show it is closely related to an intestinal species, Lactobacillus acidophilus, which has been shown to impart probiotic health benefits to humans. This relationship has fueled a prevailing hypothesis that L. helveticus is a highly specialized derivative of L. acidophilus which has adapted to acidified whey. However, L. helveticus has also been sporadically recovered from non-dairy environments, which argues the species may not be as highly specialized as is widely believed. This study employed genome sequence analysis and comparative genome hybridizations to investigate genomic diversity among L. helveticus strains collected from cheese, whey, and whiskey malt, as well as commercial cultures used in manufacture of cheese or bioactive dairy foods. Results revealed considerable variability in gene content between some L. helveticus strains, and indicated the species should not be viewed as a strict dairy-niche specialist. In addition, comparative genomic analyses provided new insight on several industrially and ecologically important attributes of L. helveticus that may facilitate commercial strain selection.