scholarly journals Caracterização físico-química do leite fermentado por Lactobacillus helveticus adicionado de extrato de hibisco durante a estocagem

2022 ◽  
Vol 11 (1) ◽  
pp. e18211124475
Author(s):  
Marina Levorato de Moraes ◽  
Thaysa Fernandes Moya Moreira ◽  
Vanessa Carvalho Rodrigues ◽  
Fernanda Vitória Leimann ◽  
Marly Sayuri Katsuda
Keyword(s):  
Tween 80 ◽  
Streptococcus Thermophilus ◽  
Lactobacillus Helveticus

Este trabalho propôs desenvolver um leite fermentado por Lactobacillus helveticus (LH) ou associada com cultura de Streptococcus thermophilus (LHST) adicionado de extrato de hibisco e avaliar a atividade antioxidante e evolução do crescimento das culturas láticas durante a estocagem sob refrigeração a 4 ± 1ºC. O leite fermentado recebeu extrato de hibisco na forma livre (LHExL e LHSTExL) ou encapsulado com PVP e Tween 80 (LHExE e LHSTExE). Avaliou-se a atividade antioxidante (DPPH e FRAP) nos tempos de 1, 15 e 30 dias. Os resultados demonstraram que o teor de acidez titulável foi inferior após a fermentação. A viabilidade das bactérias láticas foi satisfatória, as quais atenderam os requisitos legais e mantiveram estáveis até 30 dias de estocagem para ambas as caldas do leite fermentado (LH e LHST). A atividade antioxidante frente ao radical DPPH foi superior a 80%, porém não apresentou resultados conclusivos relativos à interação das culturas láticas e das diferentes formas de aplicação do extrato de hibisco. Porém, o LH apresentou maior atividade antioxidante pelo método FRAP quando associado ao extrato de hibisco encapsulado no tempo inicial. Esta análise permitiu observar que a associação do extrato de hibisco independente da forma veiculada ao leite fermentado aumentou a atividade antioxidante pelo método de FRAP e este manteve estável ao longo do tempo de estocagem. Portanto, o estudo permitiu concluir que o leite fermentado associado ao extrato de hibisco contribuiu com o aumento da atividade antioxidante e manteve estável ao longo do tempo de estocagem.

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.

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.

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.

I. GROWTH AND ACID PRODUCTION1

1971 ◽  
Vol 34 (1) ◽  
pp. 30-36 ◽  
Author(s):  
Antonieta Gaddi Angeles ◽  
E. H. Marth
Keyword(s):  
Growth Rates ◽  
Acid Production ◽  
Streptococcus Thermophilus ◽  
Dry Weight ◽  
Lactobacillus Helveticus ◽  
Lactobacillus Delbrueckii ◽  
Cow’S Milk ◽  
Available Nitrogen ◽  
Lactobacillus Pentosus ◽  
Cow's Milk

Soymilk with a protein content similar to that of cow's milk was prepared from soybeans (variety Chippewa 64). Soybeans were washed, soaked until 1 ml of water per gram of beans was absorbed, comminuted with water equivalent to 7.6 times their dry weight, and the mixture filtered through cheese cloth to obtain an aqueous extract free of large particles. Growth rates of 13 species of lactic-acid bacteria in sterile soymilk were generally greater than or comparable to those in cow's milk or Elliker's broth. Acid production in soymilk was not always directly related to growth rates of the organisms. Substantial formation of acid was limited to those bacteria able to utilize the sugars in soymilk, e.g., Streptococcus thermophilus, Lactobacillus delbrueckii, Lactobacillus pentosus, and Leuconostoc mesenteroides. Sources of readily available nitrogen (e.g., protein digests), when added to soymilk, enhanced acid production by S. thermophilus, the Leuconostoc species, and L. pentosus; appeared inhibitory to L. delbrueckii; and had no apparent effect on the other test cultures. Addition of whey powder, glucose, or lactose to soymilk enhanced acid production by Streptococcus lactis, Streptococcus cremoris, Streptococcus diacetilactis, Lactobacillus casei, and Lactobacillus helveticus; whereas addition of sucrose was without benefit. The presence of 0.23–0.25% titratable acid, corresponding to a pH of 5.7, caused coagulation of the sterilized soymilk.

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 Bacterial Community of Grana Padano PDO Cheese and Generical Hard Cheeses: DNA Metabarcoding and DNA Metafingerprinting Analysis to Assess Similarities and Differences

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1826
Author(s):  
Miriam Zago ◽  
Lia Rossetti ◽  
Tommaso Bardelli ◽  
Domenico Carminati ◽  
Nelson Nazzicari ◽  
...  
Keyword(s):  
Species Abundance ◽  
Streptococcus Thermophilus ◽  
Shannon Index ◽  
Lactobacillus Helveticus ◽  
Lactobacillus Delbrueckii ◽  
Predictive Capacity ◽  
Multivariate Statistical ◽  
Protected Designation Of Origin ◽  
Dna Metabarcoding ◽  
Grana Padano

The microbiota of Protected Designation of Origin (PDO) cheeses plays an essential role in defining their quality and typicity and could be applied to protect these products from counterfeiting. To study the possible role of cheese microbiota in distinguishing Grana Padano (GP) cheese from generical hard cheeses (HC), the microbial structure of 119 GP cheese samples was studied by DNA metabarcoding and DNA metafingerprinting and compared with 49 samples of generical hard cheeses taken from retail. DNA metabarcoding highlighted the presence, as dominant taxa, of Lacticaseibacillus rhamnosus, Lactobacillus helveticus, Streptococcus thermophilus, Limosilactobacillus fermentum, Lactobacillus delbrueckii, Lactobacillus spp., and Lactococcus spp. in both GP cheese and HC. Differential multivariate statistical analysis of metataxonomic and metafingerprinting data highlighted significant differences in the Shannon index, bacterial composition, and species abundance within both dominant and subdominant taxa between the two cheese groups. A supervised Neural Network (NN) classification tool, trained by metagenotypic data, was implemented, allowing to correctly classify GP cheese and HC samples. Further implementation and validation to increase the robustness and improve the predictive capacity of the NN classifier will be needed. Nonetheless, the proposed tool opens interesting perspectives in helping protection and valorization of GP and other PDO cheeses.

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