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

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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Synthesis of γ-Aminobutyric Acid by Lactic Acid Bacteria Isolated from a Variety of Italian Cheeses

Applied and Environmental Microbiology ◽

10.1128/aem.01064-07 ◽

2007 ◽

Vol 73 (22) ◽

pp. 7283-7290 ◽

Cited By ~ 232

Author(s):

S. Siragusa ◽

M. De Angelis ◽

R. Di Cagno ◽

C. G. Rizzello ◽

R. Coda ◽

...

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Lactobacillus Brevis ◽

Amino Acid Sequences ◽

Lactobacillus Delbrueckii ◽

Aminobutyric Acid ◽

Nucleotide Sequence Analysis ◽

Rrna Gene ◽

Gaba A ◽

Health Promoting

ABSTRACT The concentrations of γ-aminobutyric acid (GABA) in 22 Italian cheese varieties that differ in several technological traits markedly varied from 0.26 to 391 mg kg−1. Presumptive lactic acid bacteria were isolated from each cheese variety (total of 440 isolates) and screened for the capacity to synthesize GABA. Only 61 isolates showed this activity and were identified by partial sequencing of the 16S rRNA gene. Twelve species were found. Lactobacillus paracasei PF6, Lactobacillus delbrueckii subsp. bulgaricus PR1, Lactococcus lactis PU1, Lactobacillus plantarum C48, and Lactobacillus brevis PM17 were the best GABA-producing strains during fermentation of reconstituted skimmed milk. Except for L. plantarum C48, all these strains were isolated from cheeses with the highest concentrations of GABA. A core fragment of glutamate decarboxylase (GAD) DNA was isolated from L. paracasei PF6, L. delbrueckii subsp. bulgaricus PR1, L. lactis PU1, and L. plantarum C48 by using primers based on two highly conserved regions of GAD. A PCR product of ca. 540 bp was found for all the strains. The amino acid sequences deduced from nucleotide sequence analysis showed 98, 99, 90, and 85% identity to GadB of L. plantarum WCFS1 for L. paracasei PF6, L. delbrueckii subsp. bulgaricus PR1, L. lactis PU1, and L. plantarum C48, respectively. Except for L. lactis PU1, the three lactobacillus strains survived and synthesized GABA under simulated gastrointestinal conditions. The findings of this study provide a potential basis for exploiting selected cheese-related lactobacilli to develop health-promoting dairy products enriched in GABA.

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Evaluation of the probiotic and postbiotic potential of lactic acid bacteria from artisanal dairy products against pathogens

The Journal of Infection in Developing Countries ◽

10.3855/jidc.13404 ◽

2021 ◽

Vol 15 (01) ◽

pp. 102-112

Author(s):

Nazar Hussain ◽

Muhammad Tariq ◽

Per Erik Joakim Saris ◽

Arsalan Zaidi

Keyword(s):

Antibacterial Activity ◽

Lactic Acid ◽

Lactic Acid Bacteria ◽

Pathogenic Bacteria ◽

16S Rrna Gene Sequencing ◽

Lactobacillus Delbrueckii ◽

Human Consumption ◽

Rrna Gene ◽

Microdilution Method

Introduction: Probiotic and postbiotic potential of thirty-two strains of lactic acid bacteria (LAB), obtained earlier from artisanal dairy sources in Pakistan, have been investigated against major multi-drug resistant (MDR) and food borne pathogenic bacteria. Methodology: LAB strains were identified by 16S rRNA gene sequencing and their antibacterial activity was assessed by the microdilution method. Four LAB isolates, Weissella confusa PL6, Enterococcus faecium PL7, and Lactobacillus delbrueckii PL11 and PL13 were shortlisted. Their ability to degrade lactose and safety for human consumption in terms of hemolysis and antibiotic susceptibility were assessed in vitro. The antibacterial components in the cell-free supernatants (CFSs) of isolate cultures were characterized biochemically by HPLC. Results: Acid neutralization but not protease treatment abolished the antibacterial activity of CFSs. Lactic, acetic and propionic acids were the main acids in the CFSs, and acid production peaked in the stationary phase of growth. The antibacterial activity of the LAB cultures resulted from secretion of organic acids that lowered the pH. The strains exhibited variable ability to degrade lactose and were non-hemolytic and susceptible to the most common antibiotics. Conclusions: These LAB strains are probiotic candidates for further investigation of their postbiotic role in naturally preserving processed foods and for attenuation of lactose intolerance.

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Animal Rennets as Sources of Dairy Lactic Acid Bacteria

Applied and Environmental Microbiology ◽

10.1128/aem.03837-13 ◽

2014 ◽

Vol 80 (7) ◽

pp. 2050-2061 ◽

Cited By ~ 25

Author(s):

Margherita Cruciata ◽

Ciro Sannino ◽

Danilo Ercolini ◽

Maria L. Scatassa ◽

Francesca De Filippis ◽

...

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

16S Rrna ◽

16S Rrna Gene ◽

Streptococcus Thermophilus ◽

Species Level ◽

Lactobacillus Delbrueckii ◽

Rrna Gene ◽

Microbial Composition ◽

Content Type

ABSTRACTThe microbial composition of artisan and industrial animal rennet pastes was studied by using both culture-dependent and -independent approaches. Pyrosequencing targeting the 16S rRNA gene allowed to identify 361 operational taxonomic units (OTUs) to the genus/species level. Among lactic acid bacteria (LAB),Streptococcus thermophilusand some lactobacilli, mainlyLactobacillus crispatusandLactobacillus reuteri, were the most abundant species, with differences among the samples. Twelve groups of microorganisms were targeted by viable plate counts revealing a dominance of mesophilic cocci. All rennets were able to acidify ultrahigh-temperature-processed (UHT) milk as shown by pH and total titratable acidity (TTA). Presumptive LAB isolated at the highest dilutions of acidified milks were phenotypically characterized, grouped, differentiated at the strain level by randomly amplified polymorphic DNA (RAPD)-PCR analysis, and subjected to 16S rRNA gene sequencing. Only 18 strains were clearly identified at the species level, asEnterococcus casseliflavus,Enterococcus faecium,Enterococcus faecalis,Enterococcus lactis,Lactobacillus delbrueckii, andStreptococcus thermophilus, while the other strains, all belonging to the genusEnterococcus, could not be allotted into any previously described species. The phylogenetic analysis showed that these strains might represent different unknown species. All strains were evaluated for their dairy technological performances. All isolates produced diacetyl, and 10 of them produced a rapid pH drop in milk, but only 3 isolates were also autolytic. This work showed that animal rennet pastes can be sources of LAB, mainly enterococci, that might contribute to the microbial diversity associated with dairy productions.

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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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Selection of Amine-Oxidizing Dairy Lactic Acid Bacteria and Identification of the Enzyme and Gene Involved in the Decrease of Biogenic Amines

Applied and Environmental Microbiology ◽

10.1128/aem.01051-16 ◽

2016 ◽

Vol 82 (23) ◽

pp. 6870-6880 ◽

Cited By ~ 23

Author(s):

Rosa Guarcello ◽

Maria De Angelis ◽

Luca Settanni ◽

Sabino Formiglio ◽

Raimondo Gaglio ◽

...

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Biogenic Amines ◽

Multicopper Oxidase ◽

Defined Medium ◽

Health Concern ◽

Rrna Gene ◽

Gene Encoding ◽

Content Type ◽

High Concentrations

ABSTRACTAccumulation of biogenic amines (BAs) in cheese and other foods is a matter of public health concern. The aim of this study was to identify the enzyme activities responsible for BA degradation in lactic acid bacteria which were previously isolated from traditional Sicilian and Apulian cheeses. The selected strains would control the concentration of BAs during cheese manufacture. First, 431 isolates not showing genes encoding the decarboxylases responsible for BA formation were selected using PCR-based methods. Ninety-four out of the 431 isolates degraded BAs (2-phenylethylamine, cadaverine, histamine, putrescine, spermine, spermidine, tyramine, or tryptamine) during cultivation on chemically defined medium. As shown by random amplification of polymorphic DNA-PCR and partial sequencing of the 16S rRNA gene, 78 of the 94 strains wereLactobacillusspecies (Lactobacillus casei,Lb. fermentum,Lb. parabuchneri,Lb. paracasei,Lb. paraplantarum, andLb. rhamnosus),Leuconostocspecies (Leuconostoc lactisandLn. mesenteroides),Pediococcus pentosaceus,Lactococcus lactis,Streptococcusspecies (StreptococcusgallolyticusandS. thermophilus),Enterococcus lactis, andWeissella paramesenteroides. A multicopper oxidase-hydrolyzing BA was purified from the most active strain,Lb. paracaseisubsp.paracaseiCB9CT. The gene encoding the multicopper oxidase was sequenced and was also detected in other amine-degrading strains ofLb. fermentum,Lb. paraplantarum, andP. pentosaceus.Lb. paracaseisubsp.paracaseiCB9CT and another strain (CACIO6CT) of the same species that was able to degrade all the BAs were singly used as adjunct starters for decreasing the concentration of histamine and tyramine in industrial Caciocavallo cheese. The results of this study disclose a feasible strategy for increasing the safety of traditional cheeses while maintaining their typical sensorial traits.IMPORTANCEBecause high concentrations of the potentially toxic biogenic amines may be found in traditional/typical cheeses, the safety of these food items should be improved. Lactic acid bacteria selected for the ability to degrade biogenic amines may be used during cheese making to control the concentrations of biogenic amines.

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Identification and probiotic properties of lactobacilli isolated from two different fermented beverages

Annals of Microbiology ◽

10.1007/s13213-019-01540-0 ◽

2019 ◽

Vol 69 (13) ◽

pp. 1557-1565 ◽

Cited By ~ 2

Author(s):

Iulia-Roxana Angelescu ◽

Medana Zamfir ◽

Mihaela-Marilena Stancu ◽

Silvia-Simona Grosu-Tudor

Keyword(s):

Antibacterial Activity ◽

Lactic Acid ◽

Lactic Acid Bacteria ◽

Pathogenic Bacteria ◽

Scientific Information ◽

Lactobacillus Delbrueckii ◽

Rrna Gene ◽

Probiotic Properties ◽

Fermented Beverages ◽

Water Kefir

Abstract Purpose Scientific information regarding the microbial content and functional aspects of fermented beverages traditionally produced in certain parts of Europe are scarce. However, such products are believed to have some health benefits and might contain functional bacterial strains, such as probiotics. The aim of the study was to identify such lactic acid bacteria strains isolated from water kefir and, for the first time, from braga, a Romanian fermented beverage made of cereals. Methods Lactic acid bacteria (LAB) were identified to species level based on (GTG)5-PCR fingerprinting and 16S rRNA gene sequencing. Selected strains were screened for their antibacterial activity and probiotic potential. Results Eight isolates belonging to seven Lactobacillus species were recovered from the two drinks. The identification of LAB involved in the fermentation of braga (Lactobacillus plantarum, Lactobacillus fermentum, and Lactobacillus delbrueckii) is firstly reported here. Five of the Lactobacillus isolates showed antibacterial activity against pathogenic bacteria, including Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, and Salmonella enterica. Moreover, most of them showed a good resistance to pH 2.5 and some survived at high concentrations of bile salts (up to 2%). Two L. plantarum isolates were able to inhibit all the indicator strains, and showed the best viability (about 70%) after a sequential treatment simulating the passage through the gastrointestinal tract. Conclusion Based on the results, the most promising candidates for designing new probiotic products are: L. plantarum BR9 from braga and L. plantarum CR1 from water kefir.

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Isolation and Screening of Salt-Tolerance Lactic Acid Bacteria Strain and Study on its Characteristic Producing Lactic Acid

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.881-883.746 ◽

2014 ◽

Vol 881-883 ◽

pp. 746-750 ◽

Cited By ~ 1

Author(s):

Dan Huang ◽

You Qing Liu ◽

Yuan Liang ◽

Xiang Mao

Keyword(s):

Lactic Acid ◽

Salt Tolerance ◽

Lactic Acid Bacteria ◽

Lactobacillus Delbrueckii ◽

Soy Sauce ◽

Alkaline Condition ◽

Rrna Gene ◽

Acid Yield ◽

Fermentation Temperature ◽

Nacl Concentration

The salt-tolerance lactic acid bacteria strain was isolationed and identified from soy sauce mash. The ability producing lactic acid was studied in different culture conditions. The salt-tolerance lactic acid bacteria strain was isolationed and screened by MRS medium with CaCO3and NaCl gradient plate from soy sauce mash. They were identified according to morphorlogy characters and 16S ribosomal RNA (rRNA) gene sequencing methods. The ability producing lactic acid was studied at different fermentation temperature, NaCl concentration and pH value. The results showed: the strain with superior salt-tolerant was identified asLactobacillus delbrueckii subsp. bulgaricus. Its optimum fermentation temperature was 38°C. When NaCl concentration was 18%, its lactic acid yield could reach 22.68 g/L. It had a better absorbing ability of lactic acid in neutral or slight alkaline condition.

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Selection of lactic acid bacteria for exopolysaccharide production

Annals of Tropical Research ◽

10.32945/atr4025.2018 ◽

2018 ◽

pp. 61-68

Author(s):

Ivy Emnace ◽

Erlinda Dizon

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Lactobacillus Rhamnosus ◽

Defined Medium ◽

Viable Count ◽

Total Sugar ◽

Lactobacillus Delbrueckii ◽

Test Organisms ◽

Phenol Sulfuric Acid ◽

Selection Of

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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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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