Galactokinase and beta-galactosidase-deficient strains of Streptococcus salivarius were constructed to define the pathways for lactose and galactose catabolism. It was found that S. salivarius does not possess a lactose-specific phosphoenolpyruvate phosphotransferase system (PTS), that intracellular lactose was hydrolyzed by beta-galactosidase, and that galactose is catabolized exclusively thro...

BACKGROUND Lactase enzyme supplements and probiotics with high beta-galactosidase activity may be valid treatment options for the lactose intolerance. Aim of this study was to assess whether supplementation with tilactase or Lactobacillus reuteri when compared to placebo affects hydrogen breath excretion and gastrointestinal symptoms in lactose intolerant patients during lactose breath test (H,...

The purpose of this study was to determine the in vitro deposition of both drug (albuterol sulfate) and carrier (lactose) particles in relation to each other from a dry powder inhaler formulation using an Andersen cascade impactor (ACI) and time of flight aerosol beam spectrometry (TOFABS). In addition, scanning electron microscopy (SEM) combined with X-ray microanalysis was employed to disting...

The repressor gene (lacR) of the lactose phosphotransferase system of Lactococcus lactis subsp. lactis strain MG1820 has been cloned and characterized. Transcription of lacR, into a 1.2-kilobase monocistronic messenger, is repressed approximately 5-fold during growth on lactose. Nucleotide sequence analysis of the lacR gene showed the presence of an open reading frame of 861 base pairs. The ded...

Dietary calcium is critical for the development of the human skeleton and likely plays an important role in the prevention of osteoporosis. Dairy products provide approximately three-fourths of calcium consumed in the diet and are the most concentrated sources of this essential nutrient. One obstacle that likely interferes with calcium consumption among many ethnic groups is lactose maldigestio...

Lactose is the major disaccharide found in milk, and is catabolized into glucose and galactose by the enzyme lactase. Lactose is an important energy source and ssometimes it is referred to simply as milk sugar, as it is present in high percentages in dairy products. Lactose is the primary source of carbohydrates during mammal development, and represents 40% of the energy consumed during the nur...

An attempt was made to produce carrier particles for dry powder inhalations by the surface treatment of lactose particles with aqueous ethanol solution. Drug/carrier powder mixtures were prepared consisting of lactose carriers with different particle surface properties and micronized salbutamol sulfate. These powder mixtures were aerosolized by Spinhaler, and in vitro deposition properties of s...

Growth of Escherichia coli in medium containing glucose, at a concentration insufficient to support full growth, and containing lactose, is diauxic. A mutation in the gene, CR, which determines catabolite repression specific to the lac operon, was found to relieve glucose-lactose but not glucose-maltose diauxie. Furthermore, a high concentration of lactose was shown to overcome diauxie in a CR(...

We show that sweetening of food products by natural fermentation can be achieved by a combined metabolic engineering and transcriptome analysis approach. A Lactococcus lactis ssp. cremoris strain was constructed in which glucose metabolism was completely disrupted by deletion of the genes coding for glucokinase (glk), EII(man/glc) (ptnABCD), and the newly discovered glucose-PTS EII(cel) (ptcBAC...

Alcoholic fermentation of cheese whey permeate was investigated using a recombinant flocculating Saccharomyces cerevisiae, expressing the LAC4 (coding for beta-galactosidase) and LAC12 (coding for lactose permease) genes of Kluyveromyces marxianus enabling for lactose metabolization. Data on yeast fermentation and growth on cheese whey permeate from a Portuguese dairy industry is presented. For...