Amino acid utilization by Lactococcus lactis subsp. cremoris FD1 during growth on yeast extract or casein peptone

Abstract

Quantitative analyses of the utilization of amino acids by Lactococcus luctis subsp. crernoris FD1 in yeast extract medium (YE) and in casein peptone medium (CP) have been performed. Both free and peptide-bound amino acids were measured. In the CP most amino acids are peptide-bound and some amino acids are virtually only present in peptides. Thirty-six per cent of all peptide bonds in CP are hydrolysed during fermentation (6.3 mmol peptide bonds per gram biomass formed) and there is a transition of the growth rate related ATP consumption Yx.4TP (mmol ATP g biomass-') from 25 mmol g -' to 71 mmol g-' coincident with a decrease of the peptide consumption. In YE most of the amino acids are o n the free form and only 26% of the peptide bonds are hydrolysed during fermentation (1.5 mmol peptide bonds per gram biomass formed). A constant Y,.\.,.,. = 38 mmol g-' prevails throughout the fermentation in YE.

Influence of Complex Nutrient Source on Growth of and Curvacin A Production by Sausage Isolate Lactobacillus curvatus LTH 1174

“…However, supplementing the medium with asparagine had no effect on the growth rate or sakacin P production by this strain (3). A study with L. sakei Lb790/ pMLS114, a bacteriocin-negative strain transformed with a plasmid containing the sakacin P gene cluster, indicated complete consumption of the amino acids serine, asparagine, and aspartic acid.…”

“…This is not the case in sausage batter, a nutrient-rich environment, usually with added carbohydrates, where increases in free amino acids and peptides are evident during ripening of the sausage (8). It is unclear which compound(s) is responsible for the limitation of cell growth in cultivation media, but sugars, amino acids, and vitamins seem to be the most important (3,19,24,30,35,39). Consequently, to mimic meat environments, nutrient-rich environments have to be employed.…”

Growth of the Bacteriocin-Producing Lactobacillus sakei Strain CTC 494 in MRS Broth Is Strongly Reduced Due to Nutrient Exhaustion: a Nutrient Depletion Model for the Growth of Lactic Acid Bacteria

“…However, the dissociated molecules may play a minor role as well (29,31). Due to the complexity of both nutrient requirements and availability, it remains rather unclear which compounds are precisely responsible for limitation of the cell growth, but sugars and amino acids seem to be the most crucial factors (2,13,16,23,33). The need for essential minerals, such as manganese and magnesium, has also been documented (23).…”

The Metabolic Network of Lactococcus lactis : Distribution of 14 C-Labeled Substrates between Catabolic and Anabolic Pathways

“…This is established for some amino acids converted to oxo or hydroxy acids involved in cheese flavor compounds (36). It has also been shown that serine can be deaminated to give pyruvate and then lactate (3,18). In this case, the operation of this catabolic pathway modifies the calculated value of the lactate yield from the sugar and confirms that carbon balancing based solely upon sugar-to-product conversion cannot be used alone to draw conclusions about carbon flux distribution.…”