Influence of addition of proteolytic strains of Lactobacillus delbrueckii subsp. bulgaricus to commercial ABT starter cultures on texture of yoghurt, exopolysaccharide production and survival of bacteria

2002 ◽  
Vol 12 (9) ◽  
pp. 765-772 ◽  
Author(s):  
A Shihata ◽  
N.P Shah
Keyword(s):  
Starter Cultures ◽  
Lactobacillus Delbrueckii ◽  
Exopolysaccharide Production ◽  
Lactobacillus Delbrueckii Subsp

scholarly journals Antimicrobial Susceptibility of Lactobacillus delbrueckii subsp. lactis from Milk Products and Other Habitats

Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3145
Author(s):  
Noam Shani ◽  
Simone Oberhaensli ◽  
Hélène Berthoud ◽  
Remo S. Schmidt ◽  
Hans-Peter Bachmann
Keyword(s):  
Antibiotic Resistance ◽  
Antimicrobial Susceptibility ◽  
Antibiotic Resistance Genes ◽  
Starter Cultures ◽  
Lactobacillus Delbrueckii ◽  
Minimal Inhibitory Concentrations ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Positive Results ◽  
Lactobacillus Delbrueckii Subsp

As components of many cheese starter cultures, strains of Lactobacillus delbrueckii subsp. lactis (LDL) must be tested for their antimicrobial susceptibility to avoid the potential horizontal transfer of antibiotic resistance (ABR) determinants in the human body or in the environment. To this end, a phenotypic test, as well as a screening for antibiotic resistance genes (ARGs) in genome sequences, is commonly performed. Historically, microbiological cutoffs (MCs), which are used to classify strains as either ‘sensitive’ or ‘resistant’ based on the minimal inhibitory concentrations (MICs) of a range of clinically-relevant antibiotics, have been defined for the whole group of the obligate homofermentative lactobacilli, which includes LDL among many other species. This often leads to inaccuracies in the appreciation of the ABR status of tested LDL strains and to false positive results. To define more accurate MCs for LDL, we analyzed the MIC profiles of strains originating from various habitats by using the broth microdilution method. These strains’ genomes were sequenced and used to complement our analysis involving a search for ARGs, as well as to assess the phylogenetic proximity between strains. Of LDL strains, 52.1% displayed MICs that were higher than the defined MCs for kanamycin, 9.9% for chloramphenicol, and 5.6% for tetracycline, but no ARG was conclusively detected. On the other hand, all strains displayed MICs below the defined MCs for ampicillin, gentamycin, erythromycin, and clindamycin. Considering our results, we propose the adaptation of the MCs for six of the tested clinically-relevant antibiotics to improve the accuracy of phenotypic antibiotic testing.

Production of natural folates by lactic acid bacteria starter cultures isolated from artisanal Argentinean yogurts

2012 ◽  
Vol 58 (5) ◽  
pp. 581-588 ◽  
Author(s):  
Jonathan Emiliano Laiño ◽  
Jean Guy LeBlanc ◽  
Graciela Savoy de Giori
Keyword(s):  
Lactic Acid ◽  
Folic Acid ◽  
Lactic Acid Bacteria ◽  
Culture Medium ◽  
Streptococcus Thermophilus ◽  
Starter Cultures ◽  
Lactobacillus Delbrueckii ◽  
Nonfat Milk ◽  
Native Strains ◽  
Lactobacillus Delbrueckii Subsp

Folate is a B-group vitamin that cannot be synthesized by humans and must be obtained exogenously. Although some species of lactic acid bacteria (LAB) can produce folates, little is known about the production of this vitamin by yogurt starter cultures. Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus strains were isolated from artisanal Argentinean yogurts and were grown in folate-free culture medium (FACM) and nonfat milk after which intracellular and extracellular folate production were evaluated. From the initial 92 isolated LAB strains, 4 L. delbrueckii subsp. bulgaricus and 32 S. thermophilus were able to grow in the absence of folate. Lactobacillus delbrueckii subsp. bulgaricus CRL 863 and S. thermophilus CRL 415 and CRL 803 produced the highest extracellular folate levels (from 22.3 to 135 µg/L) in FACM. In nonfat milk, these strains were able to increase the initial folate concentrations by almost 190%. This is the first report where native strains of L. delbrueckii subsp. bulgaricus were shown to produce natural folate. The LAB strains identified in this study could be used in developing novel fermented products bio-enriched in natural folates that could in turn be used as an alternative to fortification with the controversial synthetic chemical folic acid.

INVESTIGATION OF THE RHEOLOGICAL CHARACTERISTICS AND LEVEL OF SYNTHESIS OF EXOPOLYSACCHARIDES (EPS) BY THE CONSORTIUM OF STREPTOCOCCUS SALIVARIUS SUBSP. THERMOPHILUS AND LACTOBACILLUS DELBRUECKII SUBSP. BULGARICUS AT DIFFERENT TEMPERATURE IN PROCESS OF MILK FERMENTATION

2020 ◽  
pp. 58-67
Author(s):  
O. Golovach ◽  
M. Babitskaya ◽  
N. Zhabanos ◽  
I. Pyzhik ◽  
M. Korkina ◽  
...  
Keyword(s):  
Raw Materials ◽  
Skim Milk ◽  
Starter Cultures ◽  
Lactobacillus Delbrueckii ◽  
Streptococcus Salivarius ◽  
Temperature Conditions ◽  
Fermentation Temperature ◽  
Organoleptic Characteristics ◽  
Milk Fermentation ◽  
Lactobacillus Delbrueckii Subsp

The article provides the results of studies on the influence of temperature conditions of milk fermentation in the manufacture of yogurt on the characteristics of milk clots and the level of EPS production. The characteristics of the samples of reconstituted skim milk fermented by consortia of lactic acid microorganisms for the manufacture of starter and viscous consistency yoghurt starter cultures under temperature conditions are determined: (43 ± 1)°С, (38 ± 1)°С, (35 ± 1)°С and ( 30 ± 1)°С. It was noted that with a decrease in the fermentation temperature from (43±1)°C to (30±1)°С, the organoleptic characteristics of the formed clot are evaluated differently. At the fermentation temperature of (30±1)°С, the lowest degree of syneresis was noted: 45% for the consortium, during the fermentation of milk raw materials forming clumps of inviscid consistency, 29% for the consortium, during the fermentation of milk raw materials forming clumps of viscous consistency. At the same time, it was found that at fermentation temperatures of (43±1)°С and (30±1)°С, the highest level of EPS synthesis for consortia was noted: (2107 ST-A+2674 TL-AV) – 874.6 and 667.9 μg / ml, (1141 ST-AV+2674 TLAV) – 683.9 and 541.3 μg / ml.

scholarly journals Improvement of the Texture of Yogurt by Use of Exopolysaccharide Producing Lactic Acid Bacteria

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Xue Han ◽  
Zhe Yang ◽  
Xueping Jing ◽  
Peng Yu ◽  
Yingchun Zhang ◽  
...  
Keyword(s):  
Dairy Products ◽  
Starter Culture ◽  
Streptococcus Thermophilus ◽  
Fermented Milk ◽  
Starter Cultures ◽  
Lactobacillus Delbrueckii ◽  
Exopolysaccharide Production ◽  
Fermented Dairy Products ◽  
Fermented Dairy

19Streptococcus thermophiluswith high exopolysaccharide production were isolated from traditional Chinese fermented dairy products. The exopolysaccharide and viscosity of milk fermented by these 19 isolates were assayed. The strains ofStreptococcus thermophiluszlw TM11 were selected because its fermented milk had the highest exopolysaccharide content (380 mg/L) and viscosity (7716 mpa/s). ThenStreptococcus thermophiluszlw TM11 was combined withLactobacillus delbrueckiisubsp.bulgaricus3 4.5 and the combination was named SH-1. The quality of the yogurt fermented by SH-1 and two commercial starter cultures (YO-MIX 465, YF-L711) were compared. It was shown that the exopolysaccharide content of yogurt fermented by SH-1 was similar to that of yogurt fermented by YF-L711 and significantly higher than YO-MIX 465 (p<0.05). In addition, the yogurt fermented by SH-1 had the lowest syneresis (8.5%) and better texture and sensory than the samples fermented by YO-MIX 465 and YF-L711. It manifested that the selected higher exopolysaccharide production starter SH-1 could be used as yogurt starter and reduce the amount of adding stabilizer, which can compare with the imported commercial starter culture.

scholarly journals Biodiversity and Safety Assessment of Half-Century Preserved Natural Starter Cultures for Pecorino Romano PDO Cheese

2021 ◽  
Vol 9 (7) ◽  
pp. 1363
Author(s):  
Luigi Chessa ◽  
Antonio Paba ◽  
Elisabetta Daga ◽  
Ilaria Dupré ◽  
Roberta Comunian
Keyword(s):  
Enterococcus Faecium ◽  
Safety Assessment ◽  
Streptococcus Thermophilus ◽  
Starter Cultures ◽  
Lactobacillus Delbrueckii ◽  
Strain Level ◽  
New Approach ◽  
The 1960S ◽  
Product Specification ◽  
Lactobacillus Delbrueckii Subsp

The use of biodiverse autochthonous natural starter cultures to produce typical and PDO cheeses contributes to establishing a link between products and territory of production, which commercial starters, constituted by few species and strains, are not able to. The purpose of this work was the assessment of biodiversity, at strain level, and safety of natural scotta-innesto cultures whose use is mandatory for the Pecorino Romano PDO cheese manufacturing, according to its product specification. The biodiversity of three scotta-innesto, collected in the 1960s and preserved in lyophilised form, was assessed by molecular biotyping using both PFGE and (GTG)5 rep-PCR profiling on 209 isolates belonging to Streptococcus thermophilus (30), Lactobacillus delbrueckii subsp. lactis (72), Enterococcus faecium (87), and Limosilactobacillus reuteri (20), revealing high biodiversity, at the strain level, in the cultures. The cultures’ safety was proved through a new approach assessing phenotypic and molecular antibiotic resistance of the cultures in toto, instead of single strains, while the safety of Enterococcus faecium isolates was investigated according to EFSA guidelines. The use of natural biodiverse cultures for the production of microbial starters for typical and PDO cheeses, such as Pecorino Romano, could be an opportunity for recovering the cheese microbiota biodiversity lost during years of commercial starters use.

Sign in / Sign up

Export Citation Format

Share Document