scholarly journals ISOLATION, CLASSIFICATION AND IDENTIFICATION OF POTENTIAL PROBIOTIC LACTOBACILLUS STRAINS FROM INFANT FAECES

2011 ◽  
Vol 14 (4) ◽  
pp. 62-76
Author(s):  
Khanh Quoc Hoang ◽  
Thanh Thi Lan Pham

Lactobacillus bacteria present in many probiotic products. This paper investigated probiotic Lactobacillus strains isolated from the human gastrointestinal tract. 15 Lactobacillus strains were isolated from breast-fed infant faeces and identified by both traditional methods and genus-specific PCR method. In vitro experiments were designed to investigate some probiotic properties such as resistance to low pH and bile, cell surface hydrophobicity, antimicrobial activity, bacteriocin and other antimicrobials production, antibiotic resistance and cholesterol reduction. As a result, 12 probiotic Lactobacillus strains were selected. Significantly, 11 strains of them reduced 10-33.34 % serum cholesterol level. By 16S rDNA analysis, the probiotic strains were classified at species level as Lactobacillus gasseri, L. fermentum, L. salivarius, L. rhamnosus and L. paracasei/ casei.

1999 ◽  
Vol 62 (3) ◽  
pp. 252-256 ◽  
Author(s):  
C. GUSILS ◽  
A. PÉREZ CHAIA ◽  
S. GONZÁLEZ ◽  
G. OLIVER

Lactobacillus strains were tested for their in vitro probiotic properties. Cell surface hydrophobicity was found to be very high for Lactobacillus fermentum subsp. cellobiosus and Salmonella Gallinarum; high values could indicate a greater ability to adhere to epithelial cells. Studies on Lactobacillus animalis indicated relative cell surface hydrophobicities smaller than those of L. fermentum subsp. cellobiosus and L. fermentum. L. animalis and Enterococcus faecalis were able to coaggregate with L. fermentum subsp. cellobiosus and L. fermentum, respectively, but not with Salmonella Gallinarum. After mixed-culture studies for determining suitable growth behavior, the pair of strains L. animalis plus L. fermentum subsp. cellobiosus was selected for an attempted challenge against Salmonella Gallinarum. Double and triple mixed-culture studies indicated that selected lactobacillus strains were able to retain their beneficial characteristics in the presence of Salmonella Gallinarum such as presence of lectins, production of antimicrobial compounds, and ability to grow and compete. The selected microorganisms can be considered as potential ingredients for a chicken probiotic feed formulation intended to control salmonellosis and also improve poultry sanitation.


2013 ◽  
Vol 109 (S2) ◽  
pp. S51-S62 ◽  
Author(s):  
Sergio Muñoz-Quezada ◽  
Empar Chenoll ◽  
José María Vieites ◽  
Salvador Genovés ◽  
José Maldonado ◽  
...  

The aim of the present study was to isolate, identify and characterise novel strains of lactic acid bacteria and bifidobacteria with probiotic properties from the faeces of exclusively breast-fed infants. Of the 4680 isolated colonies, 758 exhibited resistance to low pH and tolerance to high concentrations of bile salts; of these, only forty-two exhibited a strong ability to adhere to enterocytesin vitro.The identities of the isolates were confirmed by 16S ribosomal RNA (rRNA) sequencing, which permitted the grouping of the forty-two bacteria into three different strains that showed more than 99 % sequence identity withLactobacillus paracasei,Lactobacillus rhamnosusandBifidobacterium breve, respectively. The strain identification was confirmed by sequencing the 16S–23S rRNA intergenic spacer regions. Strains were assayed for enzymatic activity and carbohydrate utilisation, and they were deposited in the Collection Nationale de Cultures de Microorganismes (CNCM) of the Institute Pasteur and namedL. paracaseiCNCM I-4034,B. breveCNCM I-4035 andL. rhamnosusCNCM I-4036. The strains were susceptible to antibiotics and did not produce undesirable metabolites, and their safety was assessed by acute ingestion in immunocompetent and immunosuppressed BALB/c mouse models. The three novel strains inhibitedin vitrothe meningitis aetiological agentListeria monocytogenesand human rotavirus infections.B. breveCNCM I-4035 led to a higher IgA concentration in faeces and plasma of mice. Overall, these results suggest thatL. paracaseiCNCM I-4034,B. breveCNCM I-4035 andL. rhamnosusCNCM I-4036 should be considered as probiotic strains, and their human health benefits should be further evaluated.


2016 ◽  
Vol 54 (5) ◽  
pp. 632
Author(s):  
Nguyen Thi My Le ◽  
Nguyen Thi Huong

Lactobacillus strains are a major part of the probiotics, microflora of the intestine and of fermented foods. The aim of this study was to evaluate the potential probiotics of six Lactobacillus strains (L. fermentum 39-183; L. plantarum subsp.plantarum P-8; L. casei ATCC 334; L. rhamnosus ATCC 8530, L. brevis KB 290 and L. fermentum JMC 7776). Probiotic properties such as acid tolerance, bile resistance, bacteriocin-like activity, cell surface hydrophobicity and antibiotic resistance were assessed. In vitro results obtained showed that all Lactobacillus strains tested were able to meet the basic requirements for probiotic functions as they demonstrated probiotic characteristics such as tolerance to pH 2.0 and 2% bile salt. All Lactobacillus strains inhibited the growth of E. coli, Staphylococcus aureus and Salmonella Typhi. Among strains tested, L. plantarum subsp.plantarum P-8 showing inhibitory is very promising with inhibition zone ranging between 6.5 to 12.7 mm. The results for cell surface hydrophobicity and susceptibility against antibiotics also showed that L. fermentum JMC 7776 and L. plantarum subsp.plantarum P-8 had higher cell surface hydrophobicity than the rests.  All Lactobacillus tested were resistant to vancomycin and susceptible to streptomycin. The results obtained in this investigation will be used to select potentially probiotic strains for in vivo study


Author(s):  
Kamni Rajput ◽  
Ramesh Chandra Dubey

In this paper, an investigation on lactic acid bacterial isolates from ethnic goat raw milk samples were examined for their probiotic potential and safety parameters. For this purpose, isolated bacterial cultures were screened based on certain parameters viz., sugar fermentation, tolerance to temperature, salt, low pH, bile salts, and phenol resistance. After that, these bacterial cultures were more estimated in vitro for auto-aggregation, cell surface hydrophobicity, response to simulated stomach duodenum channel, antibiotic resistance, and antimicrobial activity. Besides, probiotic traits show the absence of gelatinase and hemolytic activity supports its safety. The isolate G24 showed good viability at different pH, bile concentration, phenol resistance and response to simulated stomach duodenum passage but it did not show gelatinase and hemolytic activities. Isolate G24 was susceptible to amikacin, carbenicillin, kanamycin, ciprofloxacin, co-trimazine, nitrofurantoin, streptomycin, and tetracycline. Isolate G24 also exhibited antimicrobial action against five common pathogenic bacteria, such as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Listeria monocytogens, and Salmonella typhimurium. It displayed the maximum auto-aggregation, cell surface hydrophobicity to different hydrocarbons. Following molecular characterization the isolate G24 was identified as Enterococcus hirae with 16S rRNA gene sequencing and phylogeny. E. hirae G24 bears the excellent properties of probiotics.


2018 ◽  
Vol 9 (4) ◽  
pp. 613-624 ◽  
Author(s):  
S. Fernández ◽  
M. Fraga ◽  
E. Silveyra ◽  
A.N. Trombert ◽  
A. Rabaza ◽  
...  

The use of native microorganisms with probiotic capacity is an alternative tool for the treatment and prevention of several diseases that affect animals, such as neonatal calf diarrhoea. The selection of probiotic strains within a collection is based on different in vitro and in vivo assays, which predict their potential. The aim of this study was to characterise a group of native Lactobacillus spp. strains isolated from faeces of healthy calves using an in vitro approach and to assess their ability to colonise the gastrointestinal tract (GIT) of calves. Native Lactobacillus spp. strains were evaluated on their capacity to survive low pH conditions and bile salts presence, biofilm formation and adhesion to both mucus and Caco-2 cells. Based on the in vitro characterisation, four strains (Lactobacillus johnsonii TP1.1, Lactobacillus reuteri TP1.3B, L. johnsonii TP1.6 and Lactobacillus amylovorus TP8.7) were selected to evaluate their capacity to colonise and persist in the GIT of calves. The assessment of enteric persistence involved an in vivo assay with oral administration of probiotics and quantification in faeces of the administered bacterial species with real-time quantitative PCR (qPCR). The study was conducted using 15 calves (1-month-old) which were divided into five groups of three animals, four of which were treated with four different selected strains and one was the control group. Strains TP1.3B and TP1.6 managed to persist in treated animals until ten days after the end of the administration period, indicating that they could be promising candidates for the design of probiotics for calves.


2019 ◽  
Vol 28 (6) ◽  
pp. 552-558
Author(s):  
Arjuna Nishantha Bandara Ellepola ◽  
Ranil Samantha Dassanayake ◽  
Ziauddin Khan

Objective: Candidal adherence to denture acrylic surfaces (DAS) and oral buccal epithelial cells (BEC), formation of candidal germ tubes (GT), candidal cell surface hydrophobicity (CSH), and hemolysin production are important pathogenic traits of Candida. The antifungal drug-induced post-antifungal effect (PAFE) also impacts the virulence of Candida. Candida dubliniensis isolates are associated with the causation of oral candidiasis which could be managed with posaconazole. Thus far there is no evidence on posaconazole-induced PAFE and its impact on adhesion-related attributes and production of hemolysin by C. dubliniensis isolates. Hence, the PAFE, adhesion to DAS and BEC, formation of GT, CSH, and hemolysin production of 20 oral C. dubliniensis isolates after brief exposure to posaconazole was ascertained. Materials and Methods: The PAFE, adherence to DAS and BEC, formation of GT, candidal CSH, and hemolysin production were investigated by hitherto described in vitro assays. Results: The mean PAFE (h) induced by posaconazole on C. dubliniensis isolates was 1.66. Exposure to posaconazole suppressed the ability of C. dubliniensis to adhere to DAS, BEC, formation of candidal GT, candidal CSH and to produce hemolysin by a reduction of 44, 33, 34, 36, and 15% (p < 0.005 to p < 0.001), respectively. Conclusion: Exposure of C. dubliniensis isolates to posaconazole for a brief period induced an antimycotic impact by subduing its growth in addition to suppressing pathogenic adherence-associated attributes, as well as production of hemolysin.


2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Zineb Benmechernene ◽  
Hanane Fatma Chentouf ◽  
Bellil Yahia ◽  
Ghazi Fatima ◽  
Marcos Quintela-Baluja ◽  
...  

Two strains (B7 and Z8) of theLeuconostoc mesenteroidessubspeciesmesenteroidesthat were isolated from Algerian camel milk from an initial pool of 13 strains and demonstrated a high ability to inhibit the growth ofListeriaspp. were selected and characterised at the phenotypic and genotypic levels. Probiotic profiling and inhibition spectra against food borne pathogens in mixed cultures were also investigated. The bacteriocin produced byL. mesenteroidesstrain B7 was identified as leucocin B by specific PCR.In vitrostudies demonstrated that bothLeuconostoc mesenteroidesstrains exhibited a marked probiotic profile, showing high survival at low pH (2-3 and 4) in the presence of 0.5%, 1%, and 2% of bile salts and at pH 3 in the presence of 3 mg/mL pepsin. Susceptibility testing against antimicrobial agents was also performed for both strains. When tested in a mixed culture withListeria innocua,Listeria ivanovii, orStaphylococcus aureus, strain B7 reduced the numbers of these species by 1.87, 1.78, and 1.38 log units, respectively. Consequently, these two strains were found to possess good probiotic propertiesin vitroand a high capacity forListeriaspp. inhibition in mixed cultures. Therefore, these strains have a favourable technological aptitude and a potential application as novel probiotic starters.


Author(s):  
Debapriya Mohanty ◽  
Manish Ranjan Saini ◽  
Swati Mohapatra

Objective: The antimicrobial activity and Probiotic properties of Lactobacillus species were evaluated. The antimicrobial compound of potent antimicrobial probiotic Lactobacillus was purified by column chromatography and its nature and stability were determined.Methods: This investigation was performed with few Lactobacillus strains of ATCC and MTCC along with certain strains isolated from different dairy sources. They were evaluated for their probiotics properties (acid tolerance, bile tolerance, bile salt hydrolase activity, cell autoaggregation, cell surface hydrophobicity and haemolytic behaviour). Agar well diffusion method was used to screen their potency to release bioactive compound against several pathogens. This potent antimicrobial compound was purified by chromatography as well as its molecular mass was estimated by following SDS-PAGE. Finally, the stability of the compound was determined against various ranges of temperature and pH.Results: Among all Lactobacillus strains, R1 was found to be a potent probiotic strain as well as cell free supernatant (CFS) of R1 showed more strong antagonistic effect against most of the pathogens. Carbohydrate fermentation and physiological characterization of strain R1 matched with Lactobacillus fermentum as per Bergey’s manual of systematic bacteriology. The molecular mass of the purified fraction was estimated at approximately 25 kDa and could be stable after heat treatment of 100 °C for 30 min and pH range of 4.5-7.0Conclusion: R1 showed highest antimicrobial activity while it has been found as Lactobacillus fermentum. It is due to the release of a bioactive compound having a molecular mass of 25 kDa. 


2020 ◽  
Vol 86 (6) ◽  
Author(s):  
Marianne Stage ◽  
Anita Wichmann ◽  
Mette Jørgensen ◽  
Natalia Ivonne Vera-Jimenéz ◽  
Malue Wielje ◽  
...  

ABSTRACT Lactobacillus rhamnosus GG is one of the most widely marketed and studied probiotic strains. In L. rhamnosus GG, the spaCBA-srtC1 gene cluster encodes pili, which are important for some of the probiotic properties of the strain. A previous study showed that the DNA sequence of the spaCBA-srtC1 gene cluster was not present in some L. rhamnosus GG variants isolated from liquid dairy products. To examine the stability of the L. rhamnosus GG genome in an industrial production process, we sequenced the genome of samples of L. rhamnosus GG (DSM 33156) collected at specific steps of the industrial production process, including the culture collection stock, intermediate fermentations, and final freeze-dried products. We found that the L. rhamnosus GG genome sequence was unchanged throughout the production process. Consequently, the spaCBA-srtC1 gene locus was intact and fully conserved in all 31 samples examined. In addition, different production batches of L. rhamnosus GG exhibited consistent phenotypes, including the presence of pili in final freeze-dried products, and consistent characteristics in in vitro assays of probiotic properties. Our data show that L. rhamnosus GG is highly stable in this industrial production process. IMPORTANCE Lactobacillus rhamnosus GG is one of the best-studied probiotic strains. One of the well-characterized features of the strain is the pili encoded by the spaCBA-srtC1 gene cluster. These pili are involved in persistence in the gastrointestinal tract and are important for the probiotic properties of L. rhamnosus GG. Previous studies demonstrated that the L. rhamnosus GG genome can be unstable under certain conditions and can lose the spaCBA-srtC1 gene cluster. Since in vitro studies have shown that the loss of the spaCBA-srtC1 gene cluster decreases certain L. rhamnosus GG probiotic properties, we assessed both the genomic stability and phenotypic properties of L. rhamnosus GG throughout an industrial production process. We found that neither genomic nor phenotypic changes occurred in the samples. Therefore, we demonstrate that L. rhamnosus GG retains the spaCBA-srtC1 cluster and exhibits excellent genomic and phenotypic stability in the specific industrial process examined here.


Fermentation ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 91
Author(s):  
Gabriela Krausova ◽  
Antonin Kana ◽  
Ivana Hyrslova ◽  
Iva Mrvikova ◽  
Miloslava Kavkova

Selenized lactic acid bacteria (LAB) represent potentially safe and effective sources of selenium (Se), essential for human health, as lactic acid fermentation improves Se bioavailability and reduces its toxicity. LAB are generally recognized as safe (GRAS) and widely used in fermented dairy products. To facilitate selenized LAB implementation as a functional food, we developed and characterized new Se-enriched strains based on the food industry commercial strains Streptococcus thermophilus CCDM 144 and Enterococcus faecium CCDM 922A as representatives of two LAB genera. We evaluated Se bioaccumulation capacity, Se biotransformation and growth ability in the presence of different sodium selenite concentrations (0–50 mg/L), and antioxidant properties (2, 2-diphenyl-1-picrylhydrazyl (DPPH) method) and cell surface hydrophobicity between Se-enriched and parental strains in vitro. Sodium selenite addition did not negatively influence growth of either strain; thus, 50 mg/L was chosen as the optimal concentration based on strain accumulation capacity. Selenization improved the antioxidant properties of both strains and significantly increased their cell surface hydrophobicity (p < 0.05). To our knowledge, this represents the first report of Se-enriched strain hydrophobicity as well as the first on Se speciation in families Enterococcaceae and Streptococcaceae. Moreover, both tested strains demonstrated good potential for Se-enrichment, providing a foundation for further in vitro and in vivo studies to confirm the suitability of these Se-enriched strains for industrial applications.


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