Etude de la nisinase produite parStreptococcus thermophilus

1962 ◽  
Vol 29 (3) ◽  
pp. 233-240 ◽  
Author(s):  
Par R. Alifax ◽  
R. Chevalier

SummaryOf several strains of lactic acid bacteria which produced nisinase,Streptococcus thermophilus, strain TJ, was the most active. The optimum pH for extraction of the nisinase from an acetone preparation of bacterial cells and for incubation of the solution containing nisin and nisinase was in the neighbourhood of 7·0. The proportions of nisin destroyed by the nisinase under various conditions were determined. Also, it has been shown that nisinase has no action on a number of antibiotics, including subtilin.

2009 ◽  
Vol 2009 ◽  
pp. 1-6 ◽  
Author(s):  
Abdelkader Mezaini ◽  
Nour-Eddine Chihib ◽  
Abdelkader Dilmi Bouras ◽  
Naima Nedjar-Arroume ◽  
Jean Pierre Hornez

In the present study, the antibacterial effect of 20 lactic acid bacteria isolates from a traditional cheese was investigated. 6 isolates showed antibacterial effect against Gram positive bacteria.Streptococcus thermophilusT2 strain showed the wide inhibitory spectrum against the Gram positive bacteria. Growth and bacteriocin production profiles showed that the maximal bacteriocin production, byS. thermophilusT2 cells, was measured by the end of the late-log phase (90 AUml−1) with a bacteriocine production rate of 9.3 (AUml−1)h−1. In addition, our findings showed that the bacteriocin, produced byS. thermophilusT2, was stable over a wide pH range (4–8); this indicates that such bacteriocin may be useful in acidic as well as nonacidic food. This preliminarily work shows the potential application of autochthonous lactic acid bacteria to improve safety of traditional fermented food.


Author(s):  
G. T. Uryadova ◽  
E. A. Gorelnikova ◽  
N. A. Fokina ◽  
A. S. Dolmashkina ◽  
L. V. Karpunina

Aim. Study of the effect of exopolysaccharides (EPS) of lactic acid cocci on cytokine activity of macrophages of mice with phagocytosis in vitro Staphylococcus aureus 209-P. Materials and methods. The EPS of Streptococcus thermophilus and Lactococcus lactis B-1662 was used in the work. At 13, 5 and 7, AMP and PMP were isolated and the phagocytosis process was modeled in vitro. After 30 minutes, 1, 6 and 24 hours, the content of pro-inflammatory cytokines IL-1a and TNF-a was determined. Results. EPSs had an ambiguous effect on the production of cytokines. The greatest effect on the synthesis was provided by EPS of S. thermophilus. Conclusion. The results of the study allow us to talk about the possibility of using EPS of S. thermophilus as a preventive immunomodulator for correction of the cytokine status of animals.


2022 ◽  
Vol 8 ◽  
Author(s):  
Jie Yang ◽  
Tengqi Gao ◽  
Feng Ge ◽  
Hao Sun ◽  
Zihang Cui ◽  
...  

The demand for roasted seaweed sandwich (Porphyra yezoensis) product has risen in recent years. The product slicing process has created a huge number of scraps that are not utilized effectively. Three lactic acid bacteria (LAB) strains were used to ferment P. yezoensis sauces in this study, including Lactobacillus fermentum, Lactobacillus casei, Streptococcus thermophilus, and the mixed strains (1:1:1, v/v). The fermentation characteristics, antioxidant capacity in vitro, sensory properties, and flavoring substances of fermented P. yezoensis sauces were analyzed. After 21 days of fermentation, all LAB strains grew well in the P. yezoensis sauces, with protease activity increased to 6.6, 9.24, 5.06, and 5.5 U/mL, respectively. Also, the flavors of P. yezoensis sauces fermented with L. casei and L. fermentum were satisfactory. On this premise, gas chromatography-mass spectrometry (GC-MS) was used to investigate the changes in gustatory compounds in P. yezoensis sauces fermented with L. casei and L. fermentum. In general, 42 and 41 volatile flavor chemicals were identified after the fermentation of L. casei and L. fermentum. Furthermore, the fermented P. yezoensis sauce possessed greater DPPH scavenging activity and ferric-reducing ability power than the unfermented P. yezoensis. Overall, the flavor and taste of P. yezoensis sauce fermented by L. casei was superior.


1999 ◽  
Vol 66 (1) ◽  
pp. 105-113 ◽  
Author(s):  
ANNE THIERRY ◽  
DELPHINE SALVAT-BRUNAUD ◽  
JEAN-LOUIS MAUBOIS

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.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Edoardo Pasolli ◽  
Francesca De Filippis ◽  
Italia E. Mauriello ◽  
Fabio Cumbo ◽  
Aaron M. Walsh ◽  
...  

Abstract Lactic acid bacteria (LAB) are fundamental in the production of fermented foods and several strains are regarded as probiotics. Large quantities of live LAB are consumed within fermented foods, but it is not yet known to what extent the LAB we ingest become members of the gut microbiome. By analysis of 9445 metagenomes from human samples, we demonstrate that the prevalence and abundance of LAB species in stool samples is generally low and linked to age, lifestyle, and geography, with Streptococcus thermophilus and Lactococcus lactis being most prevalent. Moreover, we identify genome-based differences between food and gut microbes by considering 666 metagenome-assembled genomes (MAGs) newly reconstructed from fermented food microbiomes along with 154,723 human MAGs and 193,078 reference genomes. Our large-scale genome-wide analysis demonstrates that closely related LAB strains occur in both food and gut environments and provides unprecedented evidence that fermented foods can be indeed regarded as a possible source of LAB for the gut microbiome.


2012 ◽  
Vol 113 (3) ◽  
pp. 471-478 ◽  
Author(s):  
Min Jung Kim ◽  
Seung Won Jung ◽  
Hye Ri Park ◽  
Seung Ju Lee

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Elena Franciosi ◽  
Ilaria Carafa ◽  
Tiziana Nardin ◽  
Silvia Schiavon ◽  
Elisa Poznanski ◽  
...  

“Nostrano-cheeses” are traditional alpine cheeses made from raw cow’s milk in Trentino-Alto Adige, Italy. This study identified lactic acid bacteria (LAB) developing during maturation of “Nostrano-cheeses” and evaluated their potential to produceγ-aminobutyric acid (GABA), an immunologically active compound and neurotransmitter. Cheese samples were collected on six cheese-making days, in three dairy factories located in different areas of Trentino and at different stages of cheese ripening (24 h, 15 days, and 1, 2, 3, 6, and 8 months). A total of 1,059 LAB isolates were screened using Random Amplified Polymorphic DNA-PCR (RAPD-PCR) and differentiated into 583 clusters. LAB strains from dominant clusters (n=97) were genetically identified to species level by partial 16S rRNA gene sequencing. LAB species most frequently isolated wereLactobacillus paracasei,Streptococcus thermophilus, andLeuconostoc mesenteroides. The 97 dominant clusters were also characterized for their ability in producing GABA by high-performance liquid chromatography (HPLC). About 71% of the dominant bacteria clusters evolving during cheeses ripening were able to produce GABA. Most GABA producers wereLactobacillus paracaseibut other GABA producing species includedLactococcus lactis,Lactobacillus plantarum,Lactobacillus rhamnosus,Pediococcus pentosaceus, andStreptococcus thermophilus. NoEnterococcus faecalisorSc. macedonicusisolates produced GABA. The isolate producing the highest amount of GABA (80.0±2.7 mg/kg) was aSc. thermophilus.


2007 ◽  
Vol 53 (9) ◽  
pp. 1046-1052 ◽  
Author(s):  
R. Michael Lehman ◽  
Kurt A. Rosentrater

Distillers grains are coproduced with ethanol and carbon dioxide during the production of fuel ethanol from the dry milling and fermentation of corn grain, yet there is little basic microbiological information on these materials. We undertook a replicated field study of the microbiology of distillers wet grains (DWG) over a 9 day period following their production at an industrial fuel ethanol plant. Freshly produced DWG had a pH of about 4.4, a moisture content of about 53.5% (wet mass basis), and 4 × 105 total yeast cells/g dry mass, of which about 0.1% were viable. Total bacterial cells were initially below detection limits (ca. 106 cells/g dry mass) and then were estimated to be ∼5 × 107 cells/g dry mass during the first 4 days following production. Culturable aerobic heterotrophic organisms (fungi plus bacteria) ranged between 104 and 105 CFU/g dry mass during the initial 4 day period, and lactic acid bacteria increased from 36 to 103 CFU/g dry mass over this same period. At 9 days, total viable bacteria and yeasts and (or) molds topped 108 CFU/g dry mass and lactic acid bacteria approached 106 CFU/g dry mass. Community phospholipid fatty acid analysis indicated a stable microbial community over the first 4 days of storage. Thirteen morphologically distinct isolates were recovered, of which 10 were yeasts and molds from 6 different genera, 2 were strains of the lactic-acid-producing Pediococcus pentosaceus and only one was an aerobic heterotrophic bacteria, Micrococcus luteus . The microbiology of DWG is fundamental to the assessment of spoilage, deleterious effects (e.g., toxins), or beneficial effects (e.g., probiotics) in its use as feed or in alternative applications.


2014 ◽  
Vol 1040 ◽  
pp. 319-322
Author(s):  
E.V. Bulycheva ◽  
E.I. Korotkova ◽  
O.A. Voronova

In this paper for investigation of the medicine «Lactobacterin» containing lactic acid bacteria was used luminescence method. It is shown, that spectrum of the Lactobacilli has 3 peaks from different substances. It is shown that during 2 hours the bacterial cells are alive.


2011 ◽  
Vol 2 (4) ◽  
pp. 335-339 ◽  
Author(s):  
N. Karapetkov ◽  
R. Georgieva ◽  
N. Rumyan ◽  
E. Karaivanova

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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