Effect of growth phase and growth medium on peptidase activities of starter lactic acid bacteria

Abstract

To cite this version:Emilina Simova, Dora Beshkova. Effect of growth phase and growth medium on peptidase activities of starter lactic acid bacteria. Le Lait, INRA Editions, 2007, 87 (6), pp.555-573. <hal-00895634> Lait 87 (2007 [555][556][557][558][559][560][561][562][563][564][565][566][567][568][569][570][571][572][573] Abstract -Selected, highly proteolytic strains (Lactobacillus casei ssp. casei RP0, Lactobacillus helveticus M10, Lactobacillus delbrueckii ssp. bulgaricus 2-11 and Streptococcus thermophilus TEP4) isolated from prime Kashkaval cheese, produced from raw milk in different regions of the Rhodopi Mountains in Bulgaria, were evaluated for peptidase activities (amino-, di-, tri-and endopeptidase) with 19 substrates. The effect of the growth phase and growth medium on the peptidase activities of the cell-free extracts of the strains, prepared from the mid-log phase, latelog phase and stationary phase of the cells grown in 12% reconstituted skim milk (RSM) or MRS/M17 broth were investigated. L. casei ssp. casei RP0 and L. helveticus M10 possessed by far the highest hydrolase activity, which was an indication of the presence of powerful aminopeptidases, X-prolyl-dipeptidyl aminopeptidases, proline iminopeptidases and tripeptidases. L. delbrueckii ssp. bulgaricus 2-11 had high hydrolase activity toward proline-containing substrates (alanyl-prolyl-ρ-nitroanilide and prolyl-ρ-nitroanilide). The most distinct difference between the peptidase activities of the lactobacilli and S. thermophilus TEP4 was exhibited toward the Glu-Glu substrate. The latter was very effectively hydrolyzed by S. thermophilus TEP4. The specific activities of most peptidases (over 90%) were significantly influenced by the growth phases and growth medium. The highest levels of peptidase activity of all lactic acid bacteria were obtained with cells grown in RSM in the late-log phase.growth phase / growth medium / peptidase activities / lactic acid bacteria / starters

Variation in aminopeptidase and aminotransferase activities of six cheese related Lactobacillus helveticus strains

“…We found that the peptidase activities were generally higher in the L. helveticus strains after growth in skim milk than in MRS. An exception was the activity against Pro-pNA, which was affected by the growth medium in a strain dependent manner. Similar results have been found for the two L. helveticus strains, DPC 4571 and M10 (Kenny et al, 2003;Simova & Beshkova, 2007). The results of these physiological studies are supported by the expression study using L. helveticus CNRZ 32 that showed an up-regulation of the genes pepN, pepX and pepR during growth in skim milk, an up-regulation of pepI during growth in MRS, while the same level of expression of pepC was seen in skim milk and MRS (Smeianov et al, 2007).…”

“…In L. helveticus, aminotransferase activities have been described against aromatic amino acids, branched-chain amino acids and Met as well as 11 other amino acids (Helinck, Le Bars, Moreau, & Yvon, 2004;Klein, Maillard, Thierry, Lortal, 2001;Thage, Houlberg, & Ardö , 2004). The peptidase biosynthesis of L. helveticus is under the control of nutritional regulation (Hé bert, Raya, & De Giori, 2000;Kenny, FitzGerald, O'Cuinn, Beresford, & Jordan, 2003;Simova & Beshkova, 2007). The biosynthesis of aminotransferases has received less attention though it has been shown to be influenced by the growth medium in Lactobacillus rhamnosus (Williams, Noble, Tammam, Lloyd, & Banks, 2002).…”

Effect of culturing conditions on the expression of key enzymes in the proteolytic system of Lactobacillus bulgaricus

“…Therefore, proteinase activity is a prerequisite for the growth of LAB in milk. It is reported that Lactobacillus bulgaricus has stronger proteinase activity than Lactococcus lactis (Simova and Beshkova, 2007;Griffiths and Tellez, 2013). We found that the addition of peptides to MRS resulted in the reduced transcription of the seven genes studied in exponentially growing cells, which is consistent with previous reports on the biochemical and genetic studies in dairy Lactobacilli such as Lactobacillus helveticus and Lactobacillus delbrueckii subsp.…”

Obtaining and Characteristic of the Autolysate of Lactic Acid Bacteria

“…Bulgaricus B-3964 from the collection of Scientific and production enterprise "Ariadna", Odessa (Ukraine) was maintained in 12 % sterile reconastituted skim milk (RSM) supplemented with 2 % glucose (Fluka RdH, Buchs, Switzerland) and 1 % yeast extract (Fluka RdH, Buchs, Switzerland) and stored at -80 o C. Working cultures were prepared from frozen cultures by three successive transfers in 12 % (w/v) low-heat RSM before use, and stored at 4 •C. Bacterial strain was grown at 37 o C without shaking [10].…”

“…The autolytic enzyme system exhibits its greatest activity during the exponential growth phase and is not detectable during the stationary phase [10,11]. Therefore, BM autolysis was carried out at the end of the logarithmic phase of growth at the temperatures of 37-90 o C (after eight hours of cultivation) and after stationary growth phase (24 hours of cultivation), maintaining it at the temperatures of 37-90 o C for 7 days.…”