Influence of thermophilic lactic acid bacteria strains on propionibacteria growth and lactate consumption in an Emmental juice-like medium

1999 ◽  
Vol 66 (1) ◽  
pp. 105-113 ◽  
Author(s):  
ANNE THIERRY ◽  
DELPHINE SALVAT-BRUNAUD ◽  
JEAN-LOUIS MAUBOIS
Keyword(s):  
Amino Acids ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Free Amino Acids ◽  
Free Amino ◽  
Streptococcus Thermophilus ◽  
Lactobacillus Helveticus ◽  
The Media ◽  
Lactate Consumption ◽  
Thermophilic Lactic Acid Bacteria

Swiss-type cheeses such as Emmental are characterized by the successive development of thermophilic lactic acid bacteria (TLAB) and propionibacteria. The aim of this study was to determine whether the choice of TLAB strain influenced propionibacteria. TLAB and propionibacteria were cultured sequentially under the conditions prevailing in cheese. Firstly, 11 Emmental juice-like media were prepared by fermenting casein-enriched milk with pure or mixed cultures of TLAB (Lactobacillus helveticus, Lb. delbrueckii subsp. lactis and Streptococcus thermophilus), differing in their proteolytic activities. TLAB cells were then removed by microfiltration. Finally, five strains of Propionibacterium freudenreichii were grown on these media at 24°C under anaerobiosis and their growth characteristics and lactate consumption determined. The media mainly differed in their contents of peptides (1·9–5·3 g/kg) and free amino acids (1·0–5·6 g/kg) and the proportions of lactate isomers (42–92% of the L(+) isomer). Propionibacteria were significantly (P<0·05) influenced by TLAB strains (differences in doubling times of up to 20% and differences in lactate consumption after 600 h culture of up to 52%). The influence of TLAB was similar for all the propionibacteria tested, depended on the TLAB strains and could not be generalized to the TLAB species. Propionibacteria were stimulated by high peptide levels, low levels of free amino acids and NaCl, a low proportion of L(+)-lactate and other undetermined factors. However, variations due to TLAB were less than those between propionibacteria strains.

scholarly journals On the Nitrogen Nutrition of Silage Strains of Lactic Acid Bacteria

1966 ◽  
Vol 19 (1) ◽  
pp. 105 ◽  
Author(s):  
CJ Brady
Keyword(s):  
Amino Acids ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Free Amino Acids ◽  
Free Amino ◽  
Nitrogen Nutrition ◽  
Synthetic Medium ◽  
Post Harvest ◽  
Synthetic Media ◽  
Time Of Harvest

Consideration is given to the adequacy of the free amino acids in plant juices at the time of harvest as nitrogen substrate for strains of lactic acid bacteria isolated from silage. The requirements of several strains of the bacteria for free amino acids in synthetic media were compared with the concentration of these acids in the liquid phase of plants at the time of harvest; this comparison suggested that several amino acids, and particulady lysine, may at times be rate.limiting. Ethanolic extracts of plants, sampled before and after a period of post-harvest wilting, were assayed as nitrogen substrates for the bacteria. A marked response to additions of lysine, some response to arginine, and evidence of deficiency of other acids were noted. The importance of post-harvest proteolysis to the amino acid nutrition of the bacteria in the silage environment is discussed. Certain fractions of the plant extracts were found to promote early growth of the bacteria in the synthetic medium, and the distribution of this activity in different fractions is described.

Antibiotic susceptibility of different lactic acid bacteria strains

2011 ◽  
Vol 2 (4) ◽  
pp. 335-339 ◽  
Author(s):  
N. Karapetkov ◽  
R. Georgieva ◽  
N. Rumyan ◽  
E. Karaivanova
Keyword(s):  
Cell Wall ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactobacillus Acidophilus ◽  
Streptococcus Thermophilus ◽  
Lactobacillus Helveticus ◽  
Lactobacillus Delbrueckii ◽  
Cell Wall Synthesis ◽  
High Susceptibility ◽  
Lactobacillus Delbrueckii Subsp

Five lactic acid bacteria (LAB) strains belonging to species Lactobacillus acidophilus, Lactobacillus helveticus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus delbrueckii subsp. lactis and Streptococcus thermophilus were tested for their susceptibility to 27 antibiotics. The minimum inhibitory concentrations of each antimicrobial were determined using a microdilution test. Among the strains a high susceptibility was detected for most of the cell-wall synthesis inhibitors (penicillins, cefoxitin and vancomycin) and resistance toward inhibitors of DNA synthesis (trimethoprim/sulfonamides and fluoroquinolones). Generally, the Lactobacillus strains were inhibited by antibiotics such as chloramphenicol, erythromycin and tetracycline at breakpoint levels lower or equal to the levels defined by the European Food Safety Authority. Despite the very similar profile of S. thermophilus LC201 to lactobacilli, the detection of resistance toward erythromycin necessitates the performance of additional tests in order to prove the absence of transferable resistance genes.

Accelerated ripening of Pecorino Umbro cheese

1998 ◽  
Vol 65 (4) ◽  
pp. 631-642 ◽  
Author(s):  
ALDO CORSETTI ◽  
MARCO GOBBETTI ◽  
EMANUELE SMACCHI ◽  
MARIA DE ANGELIS ◽  
JONE ROSSI
Keyword(s):  
Amino Acids ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Free Amino ◽  
Trichloroacetic Acid ◽  
Short Peptides ◽  
Accelerated Ripening ◽  
Total Free Amino Acids ◽  
Biochemical Analyses ◽  
Dipeptidase Activities

We have investigated accelerating the ripening of Pecorino Umbro cheese by adding crude cytoplasmic extract from Pseudomonas fluorescens, non-starter lactic acid bacteria (NSLAB) or cheese slurry. Microbiological and biochemical analyses and sensory evaluation were carried out on control and experimental cheeses over 28 d ripening. In the cheeses containing NSLAB or slurry, counts of mesophilic lactobacilli ranged from log 7·6 at day 1 to ∼log 8·6 cfu/g after 28 d ripening, ∼2 log cycles higher than in the control cheese. All the experimental cheeses contained higher levels than the control of total free amino acids and N soluble at pH 4·6 and in 120 g trichloroacetic acid/l. Compared with the control, higher aminopeptidase and dipeptidase activities were found in the cheeses containing NSLAB and slurry, and especially in those containing the Pseudomonas enzyme. The cheeses containing NSLAB or slurry were characterized by an accumulation of short peptides (Mr<2000) detected by FPLC. Although the cheese containing enzyme had an atypical flavour, the addition of mesophilic lactobacilli reduced from 60 to 28 d the ripening period of Pecorino Umbro cheese, without the appearance of off flavour.

SURVIVAL OF SALMONELLA TYPHIMURIUM IN REFRIGERATED CULTURED MILKS1

1972 ◽  
Vol 35 (8) ◽  
pp. 489-495 ◽  
Author(s):  
H. s. Park ◽  
E. H. Marth
Keyword(s):  
Lactic Acid ◽  
Citric Acid ◽  
Lactic Acid Bacteria ◽  
Salmonella Typhimurium ◽  
Streptococcus Thermophilus ◽  
Lactobacillus Helveticus ◽  
Lactobacillus Bulgaricus ◽  
Refrigerated Storage ◽  
Streptococcus Lactis ◽  
Pure Cultures

Cultured skimmilks containing Salmonella typhimurium were prepared at 21, 30, or 42 C using different species of lactic acid bacteria (0.25, 1.0, and 5% inoculum) either singly or in combinations. Several commercial cultures also were used. Cultured skimmilks were stored at 11 C and tested at 3-day intervals for numbers of viable salmonellae and lactic acid bacteria and for pH. Survival of S. typhimurium varied from 6 to 9 days and from 3 to 6 days in milks cultured with 0.25% Streptococcus lactis at 21 and 30 C, respectively. Increasing the inoculum to 1% with incubation at 30 C yielded a product no more detrimental to S. typhimurium than when the lower inoculum was used at 30 C. Survival of S. typhimurium always exceeded 9 days when S. cremoris was used to make cultured skimmilks. Products made with commercial mixed cultures composed of S. lactis and S. cremoris allowed S. typhimurium to survive for periods intermediate between the extremes observed when pure cultures were used. Skimmilks cultured with Streptococcus diacetilactis and Leuconostoc citrovorum, even when skimmilks cultured with the latter organism were acidified with citric acid and incubated further, were essentially without effect on survival of S. typhimurium during refrigerated storage. Use of Streptococcus thermophilus (1% culture, 42 C incubation) yielded cultured skimmilks that were most detrimental to survival of salmonellae, whereas skimmilks fermented with Lactobacillus bulgaricus permitted survival of low numbers of salmonellae beyond 9 days. Milks cultured at 42 C with a 5% inoculum of S. thermophilus mixed with L. bulgaricus or Lactobacillus helveticus were free of viable salmonellae before the incubation was complete. Salmonellae grown in skimmilk at 21 C without a lactic culture were more resistant to inactivation during refrigerated storage than was S. typhimurium grown at 30 or 42 C.

Changes in the free amino acids and the biogenic amine contents during lactic acid fermentation of different lupin species

2016 ◽  
Vol 51 (9) ◽  
pp. 2049-2056 ◽  
Author(s):  
Elena Bartkiene ◽  
Vadims Bartkevics ◽  
Janis Rusko ◽  
Vytaute Starkute ◽  
Daiva Zadeike ◽  
...  
Keyword(s):  
Amino Acids ◽  
Lactic Acid ◽  
Biogenic Amine ◽  
Free Amino Acids ◽  
Free Amino ◽  
Lactic Acid Fermentation ◽  
Acid Fermentation

scholarly journals Evaluation of the Effect of Auxiliary Starter Yeasts With Enzyme Activities on Kazak Cheese Quality and Flavor

2020 ◽  
Vol 11 ◽  
Author(s):  
Jing Xiao ◽  
Yu Chen ◽  
Jie Li ◽  
Xuewei Shi ◽  
Li Deng ◽  
...  
Keyword(s):  
Amino Acids ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Enzyme Activities ◽  
Free Amino Acids ◽  
Free Amino ◽  
Isoamyl Acetate ◽  
Pichia Kudriavzevii ◽  
Phenethyl Acetate ◽  
Cheese Production

To investigate the effect of yeasts on Kazak cheese quality and flavor, three isolated yeasts (Kluyveromyces marxianus A2, Pichia kudriavzevii A11, and Pichia fermentans A19) were used to ferment cheeses and designated as StC, LhC, and WcC, respectively. The cheese fermented with a commercial lactic acid starter without adding yeast was used as control named LrC. The results showed that the texture of cheese added with yeasts were more brittle. K. marxianus A2 contributed to the formation of free amino acids and organic acids, especially glutamate and lactic acid. Moreover, K. marxianus A2 provides cheese with onion, oily, and floral aromas. Furthermore, P. kudriavzevii A11 promotes a strong brandy, herbaceous, and onion flavor. Although no significant aroma change was observed in PfC, it promoted the production of acetic acid, isoamyl acetate, and phenethyl acetate. These results indicate that yeasts are important auxiliary starters for cheese production.

Preservation of Lactic Acid Bacteria on Anhydrous Silica Gel for Three Years

1983 ◽  
Vol 46 (8) ◽  
pp. 699-701 ◽  
Author(s):  
MARIA C. T. DE SILVA ◽  
MARIA A. TESSI ◽  
MARIA A. MOGUILEVSKY
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Silica Gel ◽  
Streptococcus Thermophilus ◽  
Lactobacillus Helveticus ◽  
Lactobacillus Bulgaricus ◽  
Preservation Methods ◽  
Streptococcus Lactis ◽  
Streptococcus Cremoris ◽  
Negative Effect

This study, which covers three years of storage. analyzes the application of silica gel preservation methods to lactic acid bacteria widely used in yogurt and cheese fermentation. Strains of Streptococcus lactis, Streptococcus lactis subsp. diacetylactis, Streptococcus cremoris, Streptococcus thermophilus. Lactobacillus bulgaricus, Lactobacillus helveticus and a yogurt culture were adsorbed on anhydrous silica gel in screw-cap tubes or in ordinary test tubes which were subsequently flame-sealed under vacuum. During 3 years. the bacteria were tested for viability by incubation in sterile milk. All of the bacteria retained their acidifying activity, with the exception of the yogurt culture. Extending preservation for more than 2 years had a negative effect on the activity of the yogurt culture. Results obtained support the use of screw-cap tubes which, in general, were suitable to preserve suspensions of lactic acid bacteria adsorbed on anhydrous silica gel.

scholarly journals The Use of Lactic Acid Bacteria Starter Culture in the Production ofNunu, a Spontaneously Fermented Milk Product in Ghana

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Fortune Akabanda ◽  
James Owusu-Kwarteng ◽  
Kwaku Tano-Debrah ◽  
Charles Parkouda ◽  
Lene Jespersen
Keyword(s):  
Amino Acids ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Starter Culture ◽  
Antimicrobial Activities ◽  
Starter Cultures ◽  
Lactobacillus Helveticus ◽  
Milk Product ◽  
Technological Properties

Nunu, a spontaneously fermented yoghurt-like product, is produced and consumed in parts of West Africa. A total of 373 predominant lactic acid bacteria (LAB) previously isolated and identified fromNunuproduct were assessedin vitrofor their technological properties (acidification, exopolysaccharides production, lipolysis, proteolysis and antimicrobial activities). Following the determination of technological properties,Lactobacillus fermentum22-16,Lactobacillus plantarum8-2,Lactobacillus helveticus22-7, andLeuconostoc mesenteroides14-11 were used as single and combined starter cultures forNunufermentation. Starter culture fermentedNunusamples were assessed for amino acids profile and rate of acidification and were subsequently evaluated for consumer acceptability. For acidification properties, 82%, 59%, 34%, and 20% of strains belonging toLactobacillus helveticus, L. plantarum, L. fermentum, andLeu. mesenteriodes, respectively, demonstrated fast acidification properties. High proteolytic activity (>100 to 150 μg/mL) was observed for 50%Leu. mesenteroides,40%L. fermentum,41%L. helveticus, 27%L. plantarum,and 10%Ent. faeciumspecies. In starter culture fermentedNunusamples, all amino acids determined were detected inNunufermented with single starters ofL. plantarumandL. helveticusand combined starter ofL. fermntumandL. helveticus. Consumer sensory analysis showed varying degrees of acceptability forNunufermented with the different starter cultures.

scholarly journals Phenotypic and Genotypic Analysis of Amino Acid Auxotrophy in Lactobacillus helveticus CNRZ 32

2007 ◽  
Vol 74 (2) ◽  
pp. 416-423 ◽  
Author(s):  
Jason K. Christiansen ◽  
Joanne E. Hughes ◽  
Dennis L. Welker ◽  
Beatriz T. Rodríguez ◽  
James L. Steele ◽  
...  
Keyword(s):  
Amino Acids ◽  
Lactic Acid ◽  
Amino Acid ◽  
Lactic Acid Bacteria ◽  
Ornithine Decarboxylase ◽  
Lactobacillus Helveticus ◽  
Decarboxylase Activity ◽  
Biosynthetic Pathways ◽  
Ornithine Decarboxylase Activity ◽  
Genotypic Analysis

ABSTRACT The conversion of amino acids into volatile and nonvolatile compounds by lactic acid bacteria in cheese is thought to represent the rate-limiting step in the development of mature flavor and aroma. Because amino acid breakdown by microbes often entails the reversible action of enzymes involved in biosynthetic pathways, our group investigated the genetics of amino acid biosynthesis in Lactobacillus helveticus CNRZ 32, a commercial cheese flavor adjunct that reduces bitterness and intensifies flavor notes. Most lactic acid bacteria are auxotrophic for several amino acids, and L. helveticus CNRZ 32 requires 14 amino acids. The reconstruction of amino acid biosynthetic pathways from a draft-quality genome sequence for L. helveticus CNRZ 32 revealed that amino acid auxotrophy in this species was due primarily to gene absence rather than point mutations, insertions, or small deletions, with good agreement between gene content and phenotypic amino acid requirements. One exception involved the phenotypic requirement for Asp (or Asn), which genome predictions suggested could be alleviated by citrate catabolism. This prediction was confirmed by the growth of L. helveticus CNRZ 32 after the addition of citrate to a chemically defined medium that lacked Asp and Asn. Genome analysis also predicted that L. helveticus CNRZ 32 possessed ornithine decarboxylase activity and would therefore catalyze the conversion of ornithine to putrescine, a volatile biogenic amine. However, experiments to confirm ornithine decarboxylase activity in L. helveticus CNRZ 32 by the use of several methods were unsuccessful, which indicated that this bacterium likely does not contribute to putrescine production in cheese.

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