Selection of lactic acid bacteria for exopolysaccharide production

An important source of natural alternative to commercial additives that are commonly extracted from plants and animals is the exopolysaccharide (EPS) produced by lactic acid bacteria (LAB). A screening for EPS production by Lactobacillus delbrueckii, Lactobacillus rhamnosus NBRC 3425 and Weisella paramesenteroides was conducted to identify which among these three LAB would produce the highest yield of EPS. The test organisms were grown in a Semi-defined Medium (SDM) of Sanchez et al (2006) with some modifications. EPS production was confirmed by the formation of precipitate after mixing the broth medium with 95% absolute ethanol. Results of total sugar analysis by phenol-sulfuric acid assay revealed that estimated EPS yield of L. rhamnosus NBRC 3425 was significantly higher at p<0.05 than those of W. paramesenteroides and L. delbrueckii ssp. lactis with values of 0.1355g/L, 0.0652g/L and 0.0544g/L, respectively even though their viable count did not differ significantly from each other. Correspondingly, the pH of L. rhamnosus NBRC 3425 media was also significantly higher (pH 4.03) than L. delbrueckii (pH 3.60) and W. paramesenteroides (pH 3.83).

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

Food Science and Applied Biotechnology ◽

10.30721/fsab2019.v2.i1.57 ◽

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.

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Influence of ions on growth and production of exopolysaccharides by Lactobacillus delbrueckii subsp. bulgaricus NCFB 2772

Journal of Dairy Research ◽

10.1017/s002202999900391x ◽

2000 ◽

Vol 67 (1) ◽

pp. 131-135 ◽

Cited By ~ 17

Author(s):

GERT J. GROBBEN ◽

INGEBORG C. BOELS ◽

JAN SIKKEMA ◽

MARK R. SMITH ◽

JAN A. M. DE BONT

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Streptococcus Thermophilus ◽

Defined Medium ◽

Lactobacillus Delbrueckii ◽

Sugar Composition ◽

Carbohydrate Source ◽

Medium Components ◽

Number Of Factors ◽

Initial Ph

Several lactic acid bacteria produce exopolysaccharides (EPS), either attached to the cell wall or excreted into the environment as slime material. EPS produced by Lactobacillus delbrueckii subsp. bulgaricus (Lb. bulgaricus) and Streptococcus thermophilus play an important role in improving the texture and stability of yogurt and preventing syneresis (Cerning, 1990; Nakajima et al. 1990). The amount and composition of the EPS produced by lactic acid bacteria are dependent on a number of factors, such as temperature, initial pH, carbon source and the availability of minerals, vitamins and other medium components.In previous work it was shown that the production and sugar composition of the EPS from Lb. bulgaricus NCFB2772 are affected by the carbohydrate source (Grobben et al. 1995, 1996). In a simplified defined medium, from which several vitamins and trace elements were omitted, EPS production by Lb. bulgaricus significantly increased, although growth of the strain was reduced (Grobben et al. 1998).

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

European Journal of Agriculture and Food Sciences ◽

10.24018/ejfood.2020.2.4.65 ◽

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.

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Isolation of a novel strain of Lactic Acid Bacteria from traditionally fermented common lime (Citrus aurantifolia) of Assam, India and analysis of exopolymeric substances produced by the strain

10.1101/643650 ◽

2019 ◽

Author(s):

Nabajyoti Borah ◽

Arindam Barman ◽

Debabrat Baishya

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Citrus Fruit ◽

Defined Medium ◽

Lactobacillus Delbrueckii ◽

Molecular Technique ◽

Rrna Gene ◽

Bacterial Colony ◽

Citrus Aurantifolia ◽

North East

AbstractA gram positive, rod shaped and catalase negative strain of Lactic Acid Bacteria was isolated from traditionally fermented common lime (Citrus aurantifolia) of Assam, North-East India. Bacterial identification was done by using conventional morphological and biochemical methods as well as advanced molecular technique. Traditionally fermented lime juice was serially diluted on selective culture medium and growth of translucent, ropy bacterial colony was observed in the culture plate. Isolated bacteria were identified up to species level by using ribosomal RNA (rRNA) gene sequencing technique. Based on nucleotide homology and phylogenetic analysis the isolate was found to be a strain of Lactobacillus delbrueckii. This is the first report of finding this sub species of Lactic Acid Bacteria in citrus fruit product. The sequence determined in this study has been deposited in the GenBank database with sequential accession number KT198973. The bacterial isolate also produced exopolysaccharide when grown in chemically defined medium. Fourier Transform Infrared Spectroscopy (FTIR) was done for chemical and compositional characterization of partially purified exopolysaccharide.

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Could Modifications of Processing Parameters Enhance the Growth and Selection of Lactic Acid Bacteria in Cold-Smoked Salmon To Improve Preservation by Natural Means?

Journal of Food Protection ◽

10.4315/0362-028x-70.7.1607 ◽

2007 ◽

Vol 70 (7) ◽

pp. 1607-1614 ◽

Cited By ~ 8

Author(s):

ELISABETTA TOMÉ ◽

PAUL A. GIBBS ◽

PAULA C. TEIXEIRA

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Salt Content ◽

Storage Period ◽

Processing Parameters ◽

Viable Count ◽

Smoked Salmon ◽

Microbiological Analyses ◽

Natural Means ◽

Selection Of

Several smoking conditions were examined with the objective of enhancing the numbers of lactic acid bacteria (LAB) by natural means in vacuum-packaged cold-smoked salmon during 21 days of storage at 5°C. Three combinations of salting, drying, and smoking were used: (i) dry salting × time of salting (2 or 6 h); (ii) wet salting (6 h) × dry salting (6 h) × with or without sugar; and (iii) wet salting (6 h) × dry salting (6 h) × different times of smoking (2 or 6 h of drying and 2 or 6 h of smoking). Two batches were processed for each set of conditions. Determinations of pH and salt content in the water phase were carried out for products in each treatment. Microbiological analyses (total viable count, total LAB, Lactobacillus spp., and Enterobacteriaceae) also were conducted at the beginning of storage (t0) and after 21 days of refrigerated storage (t1). There were differential increases in total LAB and lactobacilli during the storage period according to the treatment performed. The most effective treatment to enhance LAB growth was6hof dry salting with sugar, 6 h of drying, and 2 h of smoking. These salting-drying-smoking conditions also selected the LAB as the dominant flora at the end of the storage period. The LAB promoted by these processing parameters seem to be potentially useful protective cultures because of their anti-Listeria activity. From the results of this research, we conclude that it is possible to enhance the growth of LAB in general and that of inhibitory strains in particular by suitable choices of processing parameters.

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

FEMS Microbiology Letters ◽

10.1093/femsle/fnaa059 ◽

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.

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Isolation and Characterization of Lactic Acid Bacteria and Yeasts from Typical Bulgarian Sourdoughs

Microorganisms ◽

10.3390/microorganisms9071346 ◽

2021 ◽

Vol 9 (7) ◽

pp. 1346

Author(s):

Mariana Petkova ◽

Petya Stefanova ◽

Velitchka Gotcheva ◽

Angel Angelov

Keyword(s):

Lactic Acid ◽

Sequence Analysis ◽

Lactic Acid Bacteria ◽

Antimicrobial Properties ◽

Matter Content ◽

Starter Cultures ◽

Rrna Gene ◽

Dry Matter Content ◽

Isolation And Characterization ◽

Selection Of

Traditional sourdoughs in Bulgaria were almost extinct during the centralized food production system. However, a rapidly developing trend of sourdough revival in the country is setting the demand for increased production and use of commercial starter cultures. The selection of strains for such cultures is based on geographical specificity and beneficial technological properties. In this connection, the aim of this study was to isolate, identify and characterize lactic acid bacteria (LAB) and yeasts from typical Bulgarian sourdoughs for the selection of strains for commercial sourdough starter cultures. Twelve samples of typical Bulgarian sourdoughs were collected from different geographical locations. All samples were analyzed for pH, total titratable acidity and dry matter content. Enumeration of LAB and yeast was also carried out. Molecular identification by 16S rDNA sequence analysis was performed for 167 LAB isolates, and 106 yeast strains were identified by ITS1-5.8S-ITS2 rRNA gene partial sequence analysis. The LAB strains were characterized according to their amylolytic and proteolytic activity and acidification capacity, and 11 strains were selected for further testing of their antimicrobial properties. The strains with the most pronounced antibacterial and antifungal activity are listed as recommended candidates for the development of starter cultures for sourdoughs or other food products.

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