Multiplex PCR for the detection of Lactobacillus pontis and two related species in a sourdough fermentation

Article Abstract:

Detection of Lactobacillus pontis and two related species in a sourdough fermentation using multiplex PCR is discussed. A DNA isolation approach based on the ultrasonic lysis of cells from single colonies was developed for speedy identification. The specific PCR assay was combined with direct DNA extraction from the organisms in the sourdough without prior cultivation to show potential of the techniques for tracing the organisms in a laboratory-scale fermentation.

Germany, Usage, Cooking, Identification and classification, Polymerase chain reaction, Cookery (Sourdough), Fermented foods, Sourdough

Pressure inactivation of Bacillus endospores

Article Abstract:

A study is conducted to determine the resistance of spores of 14 food isolates and 5 laboratory strains of Bacillus subtilis to treatments with pressure and temperature inmarshed carrots. The loss of dipicolinic acid (DPA) from spores that varied in their presence resistance is determined and spore sublethal injury is assessed by determination of the detection times for individual spores.

Bacillus (Bacteria), Bacillus, Food contamination

Functional characterization of the proteolytic system of Lactobacillus sanfranciscensis DSM 20451 during growth in sourdough

Article Abstract:

The genes of Lactobacillus sanfranciscensis strain DSM 20451 involved in peptide uptake and hydrolysis were identified and their expression during the growth in sourdough was determined. The results indicate that the accumulation of amino acid by Lactobacillus sanfranciscensis in dough is attributable to peptide hydrolysis rather than proteolysis and amino acid metabolism by Lactobacillus sanfranciscensis during growth in sourdough was limited by the peptide availability.

Physiological aspects, Genetic aspects, Bacterial genetics, Proteolysis