Verification of fresh grass feeding, pasture grazing and organic farming by cows farm milk fatty acid profile.

The present study investigated the use of fatty acid (FA) profiling in combination with chemometric modelling to verify claims for cow milk in terms of fresh grass feeding, pasture grazing and organic/biodynamic farming. The FA profile was determined for 113 tank milk samples collected in the Netherlands from 30 farms over four different months, and used to develop classification models based on the PLS-DA algorithm. Milk from cows with daily rations of fresh grass could be successfully distinguished from milk from cows with no fresh grass in their diet.

Competitive selection of lactic acid bacteria that persist in the human oral cavity.

Lactic acid bacteria (LAB) might offer opportunities as oral probiotics provided candidate strains persist in the mouth. After intake of a mixture of 69 LAB, strains of Lactobacillus fermentum and Lactobacillus salivarius were especially recovered. Coaggregation with other microbes is likely not a prerequisite for persistence since L.

High-resolution amplified fragment length polymorphism typing of Lactococcus lactis strains enables identification of genetic markers for subspecies-related phenotypes.

A high-resolution amplified fragment length polymorphism (AFLP) methodology was developed to achieve the delineation of closely related Lactococcus lactis strains. The differentiation depth of 24 enzyme-primer-nucleotide combinations was experimentally evaluated to maximize the number of polymorphisms. The resolution depth was confirmed by performing diversity analysis on 82 L.

Phenotypic and genomic diversity of Lactobacillus plantarum strains isolated from various environmental niches.

Lactobacillus plantarum is a ubiquitous microorganism that is able to colonize several ecological niches, including vegetables, meat, dairy substrates and the gastro-intestinal tract. An extensive phenotypic and genomic diversity analysis was conducted to elucidate the molecular basis of the high flexibility and versatility of this species. First, 185 isolates from diverse environments were phenotypically characterized by evaluating their fermentation and growth characteristics.

Regulatory phenotyping reveals important diversity within the species Lactococcus lactis.

The diversity in regulatory phenotypes among a collection of 84 Lactococcus lactis strains isolated from dairy and nondairy origin was explored. The specific activities of five enzymes were assessed in cell extracts of all strains grown in two different media, a nutritionally rich broth and a relatively poor chemically defined medium. The five investigated enzymes, branched chain aminotransferase (BcaT), aminopeptidase N (PepN), X-prolyl dipeptidyl peptidase (PepX), alpha-hydroxyisocaproic acid dehydrogenase (HicDH), and esterase, are involved in nitrogen and fatty acid metabolism and catalyze key steps in the production of important dairy flavor compounds.

Probiotic Lactobacillus plantarum 299v does not counteract unfavorable phytohemagglutinin-induced changes in the rat intestinal microbiota.

Application of phytohemagglutinin (PHA) in weaning feed has been suggested to stimulate intestinal epithelium maturation. In this study, PHA strongly affected the fecal bacterial population structure of rats. Escherichia coli overgrowth was not prevented by probiotic mannose-adhering Lactobacillus plantarum 299v.

Diversity analysis of dairy and nondairy Lactococcus lactis isolates, using a novel multilocus sequence analysis scheme and (GTG)5-PCR fingerprinting.

The diversity of a collection of 102 lactococcus isolates including 91 Lactococcus lactis isolates of dairy and nondairy origin was explored using partial small subunit rRNA gene sequence analysis and limited phenotypic analyses. A subset of 89 strains of L. lactis subsp.

Effective heat inactivation of Mycobacterium avium subsp. paratuberculosis in raw milk contaminated with naturally infected feces.

The effectiveness of high-temperature, short holding time (HTST) pasteurization and homogenization with respect to inactivation of Mycobacterium avium subsp. paratuberculosis was evaluated quantitatively. This allowed a detailed determination of inactivation kinetics.

Genetic diversity and biogeography of haloalkaliphilic sulphur-oxidizing bacteria belonging to the genus Thioalkalivibrio.

A group of 85 isolates of haloalkaliphilic obligately chemolithoautotrophic sulphur-oxidizing bacteria belonging to the genus Thioalkalivibrio were recently obtained from soda lakes in Mongolia, Kenya, California, Egypt and Siberia. They have been analyzed by repetitive extragenic palindromic (rep)-PCR genomic fingerprinting technique with BOX- and (GTG)5-primer set. Cluster analysis was performed using combined fingerprint profiles and a dendrogram similarity value (r) of 0.

Natural diversity and adaptive responses of Lactococcus lactis.

Lactococcus lactis is the primary model organism for lactic acid bacteria (LAB) and is widely used in the production of fermented dairy products. In recent years there has been increasing interest in strains isolated from non-dairy environments, as these exhibit a high metabolic diversity and have unique flavour-forming activities. Recent progress has been made in understanding the natural diversity and adaptive responses of L.