Toomas Paalme

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The aim of the present study was to design an in vitro model system to evaluate the probiotic potential of food. A single bioreactor system—gastrointestinal tract simulator (GITS) was chosen for process simulation on account of its considerable simplicity compared to multi-vessel systems used in previous studies. The bioreactor was evaluated by studying the(More)
The growth characteristics of Escherichia coli K-12 in the continuous culture with a smooth increase in the dilution rate (A-stat) of various carbon sources (glucose, acetate, succinate, glycerol, lactate, acetate + succinate, casamino, acids + glucose) were studied. For all substrates studied the maximum value of specific respiration rate, Q O2, remained(More)
The growth of Streptococcus salivarius subsp. thermophilus, Lactococcus lactis subsp. lactis, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus acidophilus and Lactobacillus paracasei was studied in a pH-auxostat. The computer-controlled smooth change of pH or temperature was used to study the effect of pH and temperature on the culture(More)
AIMS To assess the structure and stability of a dominant lactic acid bacteria (LAB) population during the propagation of rye sourdough in an industrial semi-fluid production over a period of 7 months. METHODS AND RESULTS The sourdough was started from a 6-year-old freeze-dried sourdough originating from the same bakery. A unique microbial consortium(More)
The response of the yeast Saccharomyces cerevisiae to sudden vs. gradual changes in different environmental stress conditions during both respiratory growth and aerobic fermentative growth in the presence of excess glucose was investigated by monitoring the level and rate of expression of the stress response protein Hsp12p using the fluorescent fusion(More)
Two novel modifications of continuous culture with gradual change of dilution rate (A-stat): D-stat and auxo-accelerostat were evaluated in the studies of the effect of changing individual environmental parameters (T, pH, pO(2), substrate concentration, etc.) on growth characteristics of different microorganisms. Common for those cultivation methods is that(More)
Shot-wise supplementation of cysteine to a yeast culture is a common means of promoting glutathione (GSH) production. In the present work, we study the accumulation kinetics of cysteine, γ-glutamylcysteine, and GSH and the expression of genes involved in GSH and sulfur metabolism in ethanol-stat fed-batch cultures as a result of switching to a medium(More)
The effect of aliphatic monocarboxylic acids (formic, acetic, propionic, valeric, octanoic and decanoic acids) on the growth and metabolic activity of Saccharomyces cerevisiae S288C was studied, using continuous cultivation method - CO(2)-auxo-accelerostat with smooth increase in the concentration of added monocarboxylic acids. Slow increase in the(More)
Lactobacillus plantarum was grown in complex media containing glucose and yeast extract. The maximum growth yield based on yeast extract consumption was 0.5 g dwt g-1. Growth yield YATP 15–17 g dwt mol ATP-1 was almost constant in the glucose limited A-stat experiment whereas in the yeast extract limited culture it increased with dilution rate. The maximum(More)
The effect of individual environmental conditions (pH, pO2, temperature, salinity, concentration of ethanol, propanol, tryptone and yeast extract) on the specific growth rate as well as ethanol and glycerol production rate of Saccharomyces cerevisiae S288C was mapped during the fermentative growth in aerobic auxo-accelerostat cultures. The obtained(More)