scholarly journals Autolysis of Lactobacillus helveticus and Propionibacterium freudenreichii in Swiss cheeses: first evidence by using species-specific lysis markers

1998 ◽  
Vol 65 (4) ◽  
pp. 609-620 ◽  
Author(s):  
FLORENCE VALENCE ◽  
ROMAIN RICHOUX ◽  
ANNE THIERRY ◽  
AIRI PALVA ◽  
SYLVIE LORTAL
Keyword(s):  
Coenzyme A ◽  
Streptococcus Thermophilus ◽  
Lactobacillus Helveticus ◽  
Propionibacterium Freudenreichii ◽  
Swiss Cheese ◽  
Specific Lysis ◽  
Cold Room ◽  
Sds Page ◽  
Intracellular Proteins ◽  
Species Specific

Lactobacillus helveticus and Propionibacterium freudenreichii are essential starters in Swiss cheesemaking and the release of their intracellular enzymes through autolysis could significantly influence ripening. To provide evidence of this lysis, cheese made from microfiltered thermized milk inoculated with Lb. helveticus ITGLH77, Prop. freudenreichii ITGP23 and a commercial Streptococcus thermophilus was assayed. Starter viability was determined and lysis was monitored during ripening by protein analysis with SDS-PAGE of aqueous cheese extracts and by immunoblot detection of intracellular proteins: dipeptidase (PepD) for Lb. helveticus and methylmalonyl coenzyme A mutase for Prop. freudenreichii. We verified that the species specificity of these lysis markers was towards the cytoplasms of all the species currently used in Swiss cheese. Lb. helveticus exhibited an almost complete loss of viability (99·9%) from the beginning of ripening in the cold room; concomitantly PepD appeared in the cheese extracts and was detected until the end of ripening. Damaged Lb. helveticus cells were also visualized by scanning electron microscopy. In addition, free PepD was also successfully detected in commercial Swiss-related cheeses. All these results clearly demonstrated the autolysis of Lb. helveticus in Swiss cheese. Prop. freudenreichii ITGP23 grew during warm room ripening and no loss of viability was detected after maximal growth (109 cfu/g cheese). Free methylmalonyl-coenzyme A mutase was detected at the end of ripening during cold storage, when the cheese extracts were concentrated 20-fold, demonstrating that the autolysis of Prop. freudenreichii was tardy and limited.

scholarly journals Autolysis and related proteolysis in Swiss cheese for two Lactobacillus helveticus strains

2000 ◽  
Vol 67 (2) ◽  
pp. 261-271 ◽  
Author(s):  
FLORENCE VALENCE ◽  
STÉPHANIE-MARIE DEUTSCH ◽  
ROMAIN RICHOUX ◽  
VALÉRIE GAGNAIRE ◽  
SYLVIE LORTAL
Keyword(s):  
Streptococcus Thermophilus ◽  
Reversed Phase ◽  
Lactobacillus Helveticus ◽  
Small Scale ◽  
Propionibacterium Freudenreichii ◽  
Reversed Phase Hplc ◽  
Peptide Hydrolysis ◽  
Similar Extent ◽  
Cold Room

Intracellular peptidases of Lactobacillus helveticus may play a major role in the proteolysis of Swiss cheeses, provided that they are released through bacterial lysis. Experimental Swiss cheeses were manufactured on a small scale from thermized and microfiltered milk using as starters (in addition to Streptococcus thermophilus and Propionibacterium freudenreichii) one of two Lb. helveticus strains, ITGLH1 and ITGLH77, which undergo lysis to different extents in vitro. All the cheeses were biochemically identical after pressing. The viability of Lb. helveticus ITGLH1 and ITGLH77 decreased to a similar extent (96–98%) while in the cold room, but the concomitant release of intracellular lactate dehydrogenase in cheeses made with strain ITGLH1 was 5–7-fold that in cheeses made with ITGLH77. Protein profiles and immunoblot detection of the dipeptidase PepD confirmed a greater degree of lysis of the ITGLH1 strain. Free active peptidases were detected in aqueous extracts of cheese for both strains, and proteolysis occurred principally in the warm room. Reversed-phase HPLC revealed a more extensive peptide hydrolysis for ITGLH1, which was confirmed by the greater release of free NH2 groups (+33%) and free amino acids (+75%) compared with ITGLH77. As the intracellular peptidase activities of ITGLH1 and ITGLH77 have previously been shown to be similar, our results indicated that the extent of lysis of Lb. helveticus could have a direct impact on the degree of proteolysis in Swiss cheeses.

scholarly journals Extracellular and intracellular DNA for bacterial profiling of long-ripened cheeses

2020 ◽  
Vol 367 (13) ◽  
Author(s):  
Tommaso Bardelli ◽  
Lia Rossetti ◽  
Miriam Zago ◽  
Domenico Carminati ◽  
Giorgio Giraffa ◽  
...  
Keyword(s):  
Lactobacillus Rhamnosus ◽  
Streptococcus Thermophilus ◽  
Lactobacillus Helveticus ◽  
Extracellular Dna ◽  
Intact Cells ◽  
Additional Information ◽  
Buffer Solutions ◽  
Novel Approach ◽  
Three Samples ◽  
Bacterial Profiling

ABSTRACT A novel approach was developed to extract the extracellular DNA (eDNA), i.e. the free DNA outside the microbial cell, compared to the intracellular DNA (iDNA). The two DNA fractions were investigated in seven long-ripened cheeses. Among different buffer solutions tested, EDTA 0.5 M at pH 8 enabled a mild homogenization of cheese samples and the highest eDNA recovery. The extraction protocol was tested on single strains of lactic acid bacteria characterizing many Italian long-ripened cheeses, such as Streptococcus thermophilus, Lactobacillus helveticus, and Lactobacillus rhamnosus. The method resulted suitable for eDNA extraction because it minimized cell-lysis, avoiding the leakage of iDNA from the cells. The yields of eDNA, ranging from 0.01 to 0.36 µg g−1 cheese, were generally higher than the iDNA, indicating that autolytic phenomena prevailed over intact cells after 8–12 months of ripening. In four of the seven cheeses, the same LAB species were detected in the eDNA and iDNA fractions by length-heterogeneity PCR, while in the remaining three samples, a higher number of species was highlighted in the eDNA compared to the corresponding iDNA. The sequential extraction of eDNA and iDNA can be applied to obtain additional information on the composition of the bacterial community in long-aged cheeses.

Effect of the addition of extracts of thermophilic lactobacilli on acid production byStreptococcus thermophilusin milk

1981 ◽  
Vol 48 (1) ◽  
pp. 139-148 ◽  
Author(s):  
Denis H. Hemme ◽  
Véronique Schmal ◽  
Jean E. Auclair
Keyword(s):  
Acid Production ◽  
Streptococcus Thermophilus ◽  
Lactobacillus Helveticus ◽  
Caseinolytic Activity ◽  
Hard Cheese

SummarySoluble extracts of 20 strains of thermophilic lactobacilli (Lactobacillus helveticus, L.lactisand L.bulgaricus) were prepared and added to milk for the culture of 10 strains ofStreptococcus thermophilus. Acid production was stimulated in 64·5% of cases for 9 of these 10 strains. The L.helveticusextracts were the most stimulatory, but the same extracts did not always strongly stimulate each strain ofStr. thermophilus. The stimulatory effects observed varied with the volume of extract and the strain ofStr. thermophilus. The exception wasStr. thermophilus385, which was never stimulated. The stimulatory effects observed were due to aminopeptidases present in the lactobacillus extracts and were not related to a general caseinolytic activity. The possible addition of such extracts to milk for cooked hard cheese is discussed.

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 Evaluation of biochemical and serological methods to identify and clustering yeast cells of oral Candida species by CHROMagar test, SDS-PAGE and ELISA

2004 ◽  
Vol 64 (2) ◽  
pp. 317-326 ◽  
Author(s):  
J. A. de O. Rodrigues ◽  
J. F. Höfling ◽  
F. C. A. Tavares ◽  
K. M. R. Duarte ◽  
R. B. Gonçalves ◽  
...  
Keyword(s):  
Candida Species ◽  
Profile Analysis ◽  
Protein Profile ◽  
Negative Control ◽  
Yeast Cells ◽  
Sds Page ◽  
Differential Medium ◽  
Oral Yeasts ◽  
Species Specific ◽  
High Level

The purpose of this work was to evaluate biochemical and serological methods to characterize and identify Candida species from the oral cavity. The strains used were five Candida species previously identified: C. albicans, C. guilliermondii, C. parapsilosis, C. krusei, C. tropicalis, and Kluyveromyces marxianus, as a negative control. The analyses were conducted through the SDS-PAGE associated with statistical analysis using software, chromogenic medium, and CHROMagar Candida (CA), as a differential medium for the isolation and presumptive identification of clinically important yeasts and an enzyme-linked immunoabsorbent assay (ELISA), using antisera produced against antigens from two C. albicans strains. This method enabled the screening of the three Candida species: C. albicans, C. tropicalis, and C. Krusei, with 100% of specificity. The ELISA using purified immunoglobulin G showed a high level of cross-reaction against protein extracts of Candida species. The SDS-PAGE method allowed the clustering of species-specific isolates using the Simple Matching coefficient, S SM = 1.0. The protein profile analysis by SDS-PAGE increases what is known about the taxonomic relationships among oral yeasts. This methodology showed good reproducibility and allows collection of useful information for numerical analysis on information relevant to clinical application, and epidemiological and systematical studies.

scholarly journals Isovaleric acid is mainly produced by Propionibacterium freudenreichii in Swiss cheese

2004 ◽  
Vol 14 (9) ◽  
pp. 801-807 ◽  
Author(s):  
Anne Thierry ◽  
Romain Richoux ◽  
Jean-René Kerjean
Keyword(s):  
Isovaleric Acid ◽  
Propionibacterium Freudenreichii ◽  
Swiss Cheese

III. LIPOLYTIC ACTIVITY1

1971 ◽  
Vol 34 (2) ◽  
pp. 69-73 ◽  
Author(s):  
Antonieta Gaddi Angeles ◽  
E. H. Marth
Keyword(s):  
Fatty Acids ◽  
Soybean Oil ◽  
Free Fatty Acids ◽  
Lactobacillus Casei ◽  
Streptococcus Thermophilus ◽  
Lactobacillus Brevis ◽  
Lactobacillus Helveticus ◽  
Lactobacillus Delbrueckii ◽  
Lactobacillus Pentosus ◽  
Streptococcus Lactis

The following lactic acid bacteria, when tested with the agar-well method, were able to hydrolyze tributyrin and triolein, but not soybean oil: Streptococcus lactis, Streptococcus cremoris, Streptococcus diacetilactis, Streptococcus thermophilus, Leuconostoc mesenteroides, Pediococcus cerevisiae, Lactobacillus delbrueckii, Lactobacillus casei, Lactobacillus pentosus, and Lactobacillus brevis. Tributyrin only was hydrolyzed by Lactobacillus helveticus. Some free fatty acids were liberated by L. casei, L. delbrueckii, and S. thermophilus in soymilk (1.9% soybean lipids) and in MRS broth fortified with 2.0% soybean oil during a 14-day period of incubation. Although L. casei and L. delbrueckii were more active in soymilk than was S. thermophilus, they released about 10% of the amount of free fatty acids liberated by Candida lipolytica during a similar incubation period.

Arcobacter cibarius sp. nov., isolated from broiler carcasses

2005 ◽  
Vol 55 (2) ◽  
pp. 713-717 ◽  
Author(s):  
Kurt Houf ◽  
Stephen L. W. On ◽  
Tom Coenye ◽  
Jan Mast ◽  
Jan Van Hoof ◽  
...  
Keyword(s):  
Dna Hybridization ◽  
Type Strain ◽  
Pairwise Comparison ◽  
Rrna Gene ◽  
Biochemical Tests ◽  
Mean Values ◽  
Specific Pcr ◽  
Sds Page ◽  
Arcobacter Butzleri ◽  
Species Specific

Twenty Gram-negative, rod-shaped, slightly curved, non-spore-forming bacteria that gave a negative result in Arcobacter species-specific PCR tests but that yielded an amplicon in an Arcobacter genus-specific PCR test were isolated from 13 unrelated broiler carcasses. Numerical analysis of the profiles obtained by SDS-PAGE of whole-cell proteins clustered all isolates in a single group distinct from the other Arcobacter species. DNA–DNA hybridization among four representative strains exhibited DNA binding values above 91 %. DNA–DNA hybridization with reference strains of the current four Arcobacter species revealed binding levels below 47 %. The G+C contents ranged between 26·8 and 27·3 mol%. Pairwise comparison of 16S rRNA gene sequences revealed the mean values for similarity to the type strain of Arcobacter cryaerophilus (97·5 %), Arcobacter butzleri (96·5 %), Arcobacter skirrowii (96·0 %) and Arcobacter nitrofigilis (95·0 %). The levels of similarity to Campylobacter and Helicobacter species were below 88 and 87 %, respectively. The isolates could be distinguished from other Arcobacter species by the following biochemical tests: catalase, oxidase and urease activities; reduction of nitrate; growth at 25 and 37 °C under aerobic conditions; growth on 2–4 % (w/v) NaCl media; and susceptibility to cephalothin. These data demonstrate that the 20 isolates represent a single novel Arcobacter species, for which the name Arcobacter cibarius sp. nov. is proposed, with LMG 21996T (=CCUG 48482T) as the type strain.

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.

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