scholarly journals Investigation of antimicrobial activity of polyphenol-enriched extracts against probiotic lactic acid bacteria

2019 ◽  
Vol 2 (1) ◽  
pp. 67
Author(s):  
Milena Dimitrova ◽  
Galin Ivanov ◽  
Kiril Mihalev ◽  
Alexander Slavchev ◽  
Ivelina Ivanova ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Food Industry ◽  
Lactobacillus Rhamnosus ◽  
Streptococcus Thermophilus ◽  
Starter Cultures ◽  
Lactobacillus Delbrueckii ◽  
Industrial Plant ◽  
Probiotic Lactic Acid Bacteria ◽  
By Products

The antimicrobial activity of polyphenol-enriched extracts from industrial plant by-products (strawberry and bilberry press residues and distilled rose petals) against probiotic lactic acid bacteria (Lactobacillus delbrueckii subsp. bulgaricus – S10 and S19; Lactobacillus rhamnosus – YW and S25; Lactobacillus gasseri – S20; Streptococcus thermophilus – S13 and S32) was investigated. The minimum inhibitory concentration (MIC) in most strains tested was found to be relatively high (from 6.25 mg.mL-1 to 12.50 mg.mL-1). The maximum concentration of polyphenols without inhibitory effect (MCWI) ranges from 0.390mg.mL-1 to 0.781mg.mL-1. The results obtained in the present study showed that among the tested lactic acid bacteria Lactobacillus delbrueckii subsp. bulgaricus – S19, Lactobacillus rhamnosus – YW and Streptococcus thermophilus – S13 had the best growth characteristics in polyphenol-enriched culture medium. These strains had the highest MIC and MCWI values and could be used as starter cultures for polyphenol-fortified fermented milks. Practical applications: The use of polyphenol-enriched extracts from industrial plant by-products (waste) – distilled rose petals (by-products of rose oil production) and strawberry and bilberry press residues (by-products of fruit juice production) contribute for improving the economic effect and for solving environmental problems in food industry. Development of functional fermented milks with combination of probiotic starter cultures and polyphenol extracts is current and perspective direction of food industry.

scholarly journals Proximate, Microbial and Sensory Characteristics of Cowpea Milk Fermented with Probiotic Starter Cultures

2020 ◽  
Vol 2 (4) ◽  
Author(s):  
Kevin Omondi Aduol ◽  
Arnold N. Onyango ◽  
Samuel M. Imathiu
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactobacillus Rhamnosus ◽  
Streptococcus Thermophilus ◽  
Sensory Attributes ◽  
Starter Cultures ◽  
Lactobacillus Delbrueckii ◽  
In Vivo Studies ◽  
Potential Health

Fermentation of cowpea milk was carried out using three mixed starter cultures containing (i) Lactobacillus acidophilus, Bifidobacterium spp, and Streptococcus thermophilus (ABT) (ii) Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus (DT) or (iii) Lactobacillus rhamnosus GR-1 and Streptococcus thermophilus (GT). Proximate composition of raw and fermented cowpea milk was determined using the AOAC methods. Lactic acid bacteria survival and sensory attributes of the fermented cowpea milk was also determined. Crude fat decreased significantly (P<0.05) after fermentation except for GT culture which led to 33.2% increase. Crude fiber was not detected in all the samples. Fermentation with GT also led to increase in protein content, although this was not significant. A decrease was observed for carbohydrate content, after fermentation, with DT culture leading to the highest decrease of 7.1%. There was a general increase in microbial growth during the first two weeks of storage (refrigeration at 4˚C). Thereafter the number reduced to Log10 4.11 cfu/ml on the 28th day of storage. No significant differences were observed for sensory attributes of taste, texture and overall acceptability. However, aroma and appearance had significant differences among the samples (P<0.05). The study demonstrated that nutritional quality of cowpea milk can be achieved through fermentation. Also, cowpea milk fermented with lactic acid bacteria produce a yoghurt-like product that can be sweetened to taste and be acceptable to consumers. The study therefore recommends that more work should be done to improve the sensory acceptability of the products and that their potential health benefits should be determined through in vivo studies.

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.

scholarly journals Screening of lactic acid bacteria producing folate and their potential use as adjunct cultures for cheese bio-enrichment

2020 ◽  
Vol 367 (9) ◽  
Author(s):  
Clara Albano ◽  
Tiziana Silvetti ◽  
Milena Brasca
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Enterococcus Faecium ◽  
Lactobacillus Rhamnosus ◽  
Streptococcus Thermophilus ◽  
Lactobacillus Delbrueckii ◽  
Folate Intake ◽  
Cultural Medium ◽  
De Man

ABSTRACT Lactic acid bacteria (LAB) can be used to increase the folate in foods by in situ fortification. Seventy LAB were screened for their ability to produce folate during growth in de Man, Rogosa and Sharpe/M17 broth. Lactobacillus casei, Lactobacillus plantarum, Lactobacillus paracasei subsp. paracasei, Lactobacillus rhamnosus, Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus thermophilus, Lactococcus lactis subsp. lactis, Enterococcus faecium and Enterococcus lactis were able to synthetize folates in the medium, even if to a different extent. The 47 folate-producing strains were further analyzed by microbiological assay, for total, extra and intracellular folate. Enterococcus faecium VC223 and E. lactis BT161 were able to produce in cultural medium 123,625.74 ± 8.00 ng/ml and 384.22 ± 5.00 ng/ml of folate, respectively. Five strains were further examined for their ability to synthesize folate in cheese. The folate content increased with ripening up to by 54% after 30 d when L. casei VC199 was used and up to 108% and 113% after 60 d, with L. paracasei SE160 and E. lactis BT161 respectively exceeding 100 ng/100g. Results encourage the use of specific LAB to obtain natural folate bio-enriched dairy products improving folate intake.

scholarly journals Suitability of the probiotic lactic acid bacteria strains as the starter cultures in unripe cornelian cherry (Cornus mas L.) fermentation

2017 ◽  
Vol 54 (9) ◽  
pp. 2936-2946 ◽  
Author(s):  
Agata Czyżowska ◽  
Alicja Z. Kucharska ◽  
Agnieszka Nowak ◽  
Anna Sokół-Łętowska ◽  
Ilona Motyl ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Starter Cultures ◽  
Cornelian Cherry ◽  
Cornus Mas ◽  
Probiotic Lactic Acid Bacteria

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.

scholarly journals Dynamic Changes of Intracellular pH in Individual Lactic Acid Bacterium Cells in Response to a Rapid Drop in Extracellular pH

2000 ◽  
Vol 66 (6) ◽  
pp. 2330-2335 ◽  
Author(s):  
Henrik Siegumfeldt ◽  
K. Björn Rechinger ◽  
Mogens Jakobsen
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactic Acid Bacterium ◽  
Intracellular Ph ◽  
Membrane Filter ◽  
Single Cells ◽  
Streptococcus Thermophilus ◽  
Extracellular Ph ◽  
Lactobacillus Delbrueckii ◽  
Rapid Drop

ABSTRACT We describe the dynamics of changes in the intracellular pH (pHi) values of a number of lactic acid bacteria in response to a rapid drop in the extracellular pH (pHex). Strains of Lactobacillus delbrueckii subsp.bulgaricus, Streptococcus thermophilus, andLactococcus lactis were investigated. Listeria innocua, a gram-positive, non-lactic acid bacterium, was included for comparison. The method which we used was based on fluorescence ratio imaging of single cells, and it was therefore possible to describe variations in pHi within a population. The bacteria were immobilized on a membrane filter, placed in a closed perfusion chamber, and analyzed during a rapid decrease in the pHex from 7.0 to 5.0. Under these conditions, the pHi of L. innocua remained neutral (between 7 and 8). In contrast, the pHi values of all of the strains of lactic acid bacteria investigated decreased to approximately 5.5 as the pHex was decreased. No pronounced differences were observed between cells of the same strain harvested from the exponential and stationary phases. Small differences between species were observed with regard to the initial pHi at pHex 7.0, while different kinetics of pHiregulation were observed in different species and also in different strains of S. thermophilus.

scholarly journals Importância das Bactérias Ácido Láticas e não Starter (NSLAB) na Tecnologia de Produção dos Derivados Lácteos

2020 ◽  
Vol 24 (4) ◽  
pp. 348-352
Author(s):  
Maria Tereza Pereira ◽  
Elsa Helena Walter de Santana ◽  
Joice Sifuentes dos Santos
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactococcus Lactis ◽  
Lactobacillus Casei ◽  
Streptococcus Thermophilus ◽  
Raw Milk ◽  
Fermented Milk ◽  
Starter Cultures ◽  
Bacillus Spp ◽  
Lactobacillus Spp

Produtos lácteos fermentados contêm bactérias ácido lácticas (BAL), naturalmente presentes ou adicionadas na matriz láctea como culturas iniciadoras (starters), contribuindo com aroma, textura, valor nutricional e segurança microbiológica. Lactobacillus spp., Streptococcus spp., Lactococcus spp. e Leuconostoc spp. são utilizados como culturas starters em laticínios. As BAL podem ser classificadas em mesofílicas (ex Lactococcus lactis) e termofílicas (ex Streptococcus thermophilus), e de acordo com seus metabólitos de fermentação em homofermentativas (ácido lático) e heterofermentativas (ácido lático, dióxido de carbono, diacetil e outros compostos flavorizantes). Entre as BAL há um grupo de bactérias lácticas que não fazem parte da cultura láctica (non starter lactic acid bacteria - NSLAB), que são oriundas do leite cru, do ambiente de ordenha ou da indústria formando biofilmes. As NSLAB são representadas por espécies heterofermentativas de lactobacilos mesofílicos como Lactobacillus casei spp., L. paracasei spp., L. rhamnosus spp. e L. plantarum spp., e ainda por Pediococcus spp., Leuconostoc spp. e Micrococcus spp. NSLAB termoduricas como Bacillus spp. também são relatadas. As NSLAB em queijos podem ajudar a desenvolver sabor e aroma, porém também são associadas aos defeitos em queijos e leites fermentados. Problemas como odores estranhos, sabor amargo ou muito ácido, perda de viscosidade, perda de coloração, estufamento e formação de gás são associados com a presença e contaminação por NSLAB. Assim, as BAL são importantes micro-organismos na indústria láctea, garantindo sabores e aromas aos derivados. Já a presença de NSLAB podem ser associados com defeitos em queijos e leites fermentados, sendo um problema na indústria beneficiadora.   Palavras-chave: Característica Sensorial. Leites Fermentados. Queijo. Textura.                       Abstract Fermented dairy products contain acid bacteria (BAL) naturally present or added to the dairy matrix as starter cultures (starters), contributing to aroma, texture, nutritional value and microbiological safety. Lactobacillus spp., Streptococcus spp., Lactococcus spp. and Leuconostoc spp. are used as starter dairy crops. As BAL it can be classified as mesophilic (ex: Lactococcus lactis) and thermophilic (ex: Streptococcus thermophilus), and agree with its fermentation metabolites in homofermentative (lactic acid) and heterofermentative (lactic acid, carbon dioxide, diacetyl and other flavorings). Among the BAL, there is a group of lactic bacteria that are not part of the dairy culture (non-initiating lactic acid bacteria - NSLAB) that originate from raw milk, the milking environment or the biofilm-forming industry. NSLAB is represented by heterofermentative species of mesophilic lactobacilli such as Lactobacillus casei spp., L. paracasei spp., L. rhamnosus spp. and L. plantarum spp., and also by Pediococcus spp., Leuconostoc spp. and Micrococcus spp. Termoduric NSLAB such as Bacillus spp. are also related. NSLAB in cheeses may help develop flavor and aroma, and they are also associated with defects in fermented cheeses and milks. Problems such as strange odors, bitter or very acidic taste, loss of viscosity, loss of color, establishment and gas training are associated with the presence and contamination by NSLAB. Thus,  BALs are important microorganisms in the dairy industry, contributing to the dairy flavors and aromas. The presence of NSLAB, on the other hand, can be associated with defects in fermented milk and cheese, being a problem in the processing industry.   Keywords: Cheese. Fermented Milk. Sensory Characteristic. Texture.

scholarly journals Sensory evaluation as a tool in assessing the quality of new fermented products

2014 ◽  
Vol 17 (3) ◽  
pp. 63-71
Author(s):  
Manhal Yousseef ◽  
Samuel Lubbers ◽  
Florence Housson ◽  
Dominique Valentin
Keyword(s):  
Product Quality ◽  
Lactobacillus Rhamnosus ◽  
Principal Component ◽  
Streptococcus Thermophilus ◽  
Starter Cultures ◽  
Lactobacillus Delbrueckii ◽  
Sensory Profile ◽  
Cow Milk ◽  
Negative Effects ◽  
Pea Protein

Ten starter cultures of lactic acid bacteria were used to ferment five mixtures of milk and pea protein (0%, 10%, 20%, 30% and 40% of pea) to select the cocktail that can lead to products similar to traditional yogurt. Product quality evaluation was performed by comparing the sensory profile of 49 formulated products with the profile of a milk fermented by commercial lactic ferments. The sensory profiles were analyzed by means of three-way ANOVAs and a principal component analysis (PCA). Substitution of cow milk protein with 40% of pea proteins reduce starter cultures effects and decrease product quality. In contrast, until 30% of pea protein, starter cultures show positive and negative effects. For example, products fermented by Streptococcus thermophilus + Lactobacillus acidophilus with 30% pea protein have positive characters like creamy and smooth, but Lactobacillus delbrueckii subsp. Bulgaricus + Lactobacillus rhamnosus caused bad quality and negative characters like bitter and astringent even with 100% cow milk.

scholarly journals Clustering of Streptococcus thermophilus Strains to Establish a Relation between Exopolysaccharide Characteristics and Gel Properties of Acidified Milk

Foods ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 146 ◽  
Author(s):  
Georg Surber ◽  
Susann Mende ◽  
Doris Jaros ◽  
Harald Rohm
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Streptococcus Thermophilus ◽  
Starter Cultures ◽  
Extracellular Polysaccharides ◽  
Gel Properties ◽  
Fermentation Time ◽  
Thread Length ◽  
Acid Gel ◽  
Fermented Dairy

In situ produced extracellular polysaccharides (EPS) from lactic acid bacteria are generally known to affect the texture of fermented dairy products; however, the interplay between EPS and product properties is still poorly understood. The aim of this study was to establish a relationship between concentration and properties of EPS, and gel formation of milk analysed by noninvasive Multispeckle Diffusing Wave Spectroscopy. Twenty Streptococcus thermophilus strains were classified with respect to EPS concentration (8–126 mg GE/kg) and ropiness (thread length: 15–80 mm). Five groups identified by cluster analysis demonstrate the high strain-to-strain variability even within one species of lactic acid bacteria. Results from acidification and gelation experiments averaged per cluster indicate that fermentation time and gel stiffness is higher for strains that produce ropy EPS. A further increase in gel stiffness was detected for strains that also produced cell-bound EPS, which underlines the importance of both ropy and cell-bound EPS for improving acid gel properties. The results may be helpful for a proper selection of EPS-producing starter cultures.

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