scholarly journals Evaluation of the Efficiency of Ethanol Precipitation and Ultrafiltration on the Purification and Characteristics of Exopolysaccharides Produced by Three Lactic Acid Bacteria

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Manel Ziadi ◽  
Taroub Bouzaiene ◽  
Sana M’Hir ◽  
Kaouther Zaafouri ◽  
Ferid Mokhtar ◽  
...  

Exopolysaccharides (EPS) produced by three Lactic Acid Bacteria strains,Lactococcus lactisSLT10,Lactobacillus plantarumC7, andLeuconostoc mesenteroidesB3, were isolated using two methods: ethanol precipitation (EPS-ETOH) and ultrafiltration (EPS-UF) through a 10 KDa cut-off membrane. EPS recovery by ultrafiltration was higher than ethanol precipitation forLactococcus lactisSLT10 andLactobacillus plantarumC7. However, it was similar with both methods forLeuconostoc mesenteroidesB3. The monomer composition of the EPS fractions revealed differences in structures and molar ratios between the two studied methods. EPS isolated fromLactococcus lactisSLT10 are composed of glucose and mannose for EPS-ETOH against glucose, mannose, and rhamnose for EPS-UF. EPS extracted fromLactobacillus plantarumC7 andLeuconostoc mesenteroidesB3 showed similar composition (glucose and mannose) but different molar ratios. The molecular weights of the different EPS fractions ranged from 11.6±1.83 to 62.4±2.94 kDa. Molecular weights of EPS-ETOH fractions were higher than those of EPS-UF fractions. Fourier transform infrared (FTIR) analysis revealed a similarity in the distribution of the functional groups (O-H, C-H, C=O, -COO, and C-O-C) between the EPS isolated from the three strains.

Genetika ◽  
2015 ◽  
Vol 47 (3) ◽  
pp. 819-832 ◽  
Author(s):  
Josip Colo ◽  
Sanja Mihajlovic ◽  
Maja Tolinacki ◽  
Mersiha Alkic ◽  
Dusanka Popovic ◽  
...  

Bosnian sudzuk is a dry fermented sausage produced in a rural household near the town of Visoko in central Bosnia and Herzegovina. This kind of sausage was manufactured only from beef and spices in a traditional way without the addition of a starter cultures. To identify lactic acid bacteria (LAB), a total number of 160 Lstrains were isolated from five samples of Bosnian sudzuk collected over 28 days of fermentation. Preliminary identification by phenotypic tests and 16S rDNA sequencing were performed for all 160 of the Lisolates. Identification of Lstrains from traditionally produced Bosnian sausage at the species level revealed the presence of six genera: Lactococcus sp., Enterococcus sp., Leuconostoc sp., Lactobacillus sp., Pediococcus sp. and Weissella sp.. Among the 15 distinct species identified, the species Lactobacillus plantarum, Leuconostoc mesenteroides, Lactococcus lactis, Enterococcus faecalis and Enterococcus durans were present throughout the entire process of fermentation. Leuconostoc mesenteroides, Lactobacillus plantarum and Lactococcus lactis prevailed, with 21.8%, 19.3% and 13.1%, respectively, of total Lstrains during the entire fermentation process. Significant negative correlations (r = 0.892 and r = 0.829, respectively) between the presence of Weissella sp. and Lactobacillus sp., and between the presence of Weissella sp. and Lactococcus sp. were recorded. Lactobacillus plantarum, Enterococcus durans and Leuconostoc mesenteroides were the best producers of aromogenic compounds while 32.3% of Lactobacillus plantarum and 28.6% of Leuconostoc mesenteroides were produced exopolysaccharides.


2019 ◽  
Vol 7 (1-2) ◽  
pp. 127-132
Author(s):  
Judit Peter Szucs ◽  
Agnes Suli ◽  
Timea Suli Zakar ◽  
Elizabet Berecz ◽  
Mate Pek

The object of the trial was to study the effect of some lactic acid bacteria strains on the fermentation and aerobic stability of whole plant maize silages.The whole plant maize raw material was 32% DM, in soft cheddar stage of grain ripeness. It was ensiled in 4.2 litre capacity glass micro-size silos in 5 replicates /each treatment and stored on constant air conditioned room temperature (22 oC) during 95 days. The average packing density of raw material was 211 kg DM/m3.The applied treatments: 1. Untreated control maize, 2. Enterococcus faecium 100,000 CFU/g fresh maize (FM), 3. Lactobacillus plantarum 50,000 CFU/g FM + Enterococcus faecium 50,000 CFU/g FM, 4. Lactococcus lactis 100,000 CFU/g FM, 5. Lactobacillus plantarum 50,000 CFU/g FM + Lactococcus lactis 50,000 CFU/g FM, 6. Lactobacillus plantarum 100,000 CFU/g FM.Aerobic stability study:  Applied Honig (1990 system).The main experiences are the following: Applied lactic acid bacteria strains improved the quality of fermentation of maize in general compare to untreated control one.Lactic acid bacteria strains significantly stimulated lactic acid production and decreased propionic and butyric acid production. The origin of ammonia decreased also under influence of lactic acid bacteria strains in unaerobic conditions.Enterococcus faecium and.Lactococcus lactis are not able to protect the maize silages against the aerobic deterioration with the applied dosage.  Lactobacillus plantarum itself produced the most favourable fermentation characteristics and protected the aerobic stability of silage the most effectively (during 4 day) compare to all other treated maize silages.


Toxins ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 288 ◽  
Author(s):  
Nguyen Tu ◽  
Nghe Dat ◽  
Le Canh ◽  
Doan Vinh

Screening for compounds that can neutralize the toxicity of tetrodotoxin (TTX) or reduce its negative effects is necessary. Our study tested the TTX detoxification capacity of exopolysaccharide (EPS) extracted from lactic acid bacteria. EPS of Leuconostoc mesenteroides N3 isolated from the Vung Tau sea (Vietnam), Lactobacillus plantarum PN05, and Lactobacillus rhamnosus PN04 were used in the study. To more completely evaluate the importance of EPS in detoxification, EPS samples of Leuconostoc mesenteroides N3, Lactobacillus plantarum PN05 and Lactobacillus rhamnosus PN04 were also tested. The majority of EPS of these bacteria contained glucose; this was observed using thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC) analysis. As observed with FTIR analysis, only EPS of Lactobacillus plantarum PN05 contained methyl groups. The results indicated that detoxification of TTX in mice could be obtained at an optimal dose of 248 µg EPS from Leuconostoc mesenteroides incubated with 54 µg cuprous oxide for 40 min or 148 µg EPS Lactobacillus rhamnosus incubated with 55 µg cuprous oxide for 40 min, while EPS from Lactobacillus plantarum showed TTX detoxification capacity without cuprous oxide combination. Consequently, EPS from Lactobacillus plantarum PN05 can be used in TTX prevention. This is the first report on the importance of lactic acid bacteria in TTX detoxification.


2011 ◽  
Vol 63 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Natasa Jokovic ◽  
Maja Vukasinovic ◽  
Katarina Veljovic ◽  
Maja Tolinacki ◽  
L. Topisirovic

Two hundred thirteen non-starter lactic acid bacteria isolated from Radan cheese during ripening were identified with both a classical biochemical test and rep-PCR with (GTG)5 primer. For most isolates, which belong to the Lactococcus lactis subsp. lactis, Leuconostoc mesenteroides, Lactobacillus plantarum, Lactobacillus paraplantarum and Enterococcus faecium, a phenotypic identification was in good agreement with rep-PCR identification. Lactococeus lactis subsp. lactis, Enterococcus faecium and subspecies from the Lenconostoc mesenteroides group were the dominant population of lactic acid bacteria in cheese until 10 days of ripening and only one Streptococcus thermophilus strain was isolated from the 5-day-old cheese sample. As ripening progressed, Lactobacillus plantarum became the predominant species together with the group of heterofermentative species of lactobacilli that could not be precisely identified with rep-PCR.


1992 ◽  
Vol 55 (6) ◽  
pp. 444-448 ◽  
Author(s):  
THOMAS J. MONTVILLE ◽  
ANN M. ROGERS ◽  
AMECHI OKEREKE

The sensitivities of proteolytic and nonproteolytic Clostridium botulinum strains to nisin and other bacteriocins were investigated. Although there were statistically different nisin sensitivities among vegetative cells from 18 C. botulinum strains, these differences were not biotype-associated. When inoculated into tryptose peptone yeast extract glucose broth containing nisin at various levels, spores from strain 56 A were not inhibited at all by 100 IU/ml of nisin. About 2,500 IU/ml was required to inhibit growth for 30 d. In contrast, only 10 IU/ml was required to inhibit strain 169 for 30 d. Both strains were completely inhibited at the 10,000 IU/ml limit allowed in processed cheeses. Spores from strains having limited (strain 56A), moderate (strain 25675), or extreme (strain 169) nisin sensitivity were examined for bacteriocin-mediated inhibition by Lactococcus lactis 11454, Pediococcus pentosaceus 43200, P. pentosaceus 43201, and Lactobacillus plantarum BN using the spot-on-the-lawn method. While the differences in nisin sensitivity were confirmed, there was no statistically significant difference in their sensitivities to the bacteriocins produced by other lactic acid bacteria.


1999 ◽  
Vol 4 (2) ◽  
pp. 61
Author(s):  
N. Guizani ◽  
K. Al-Ramadani

Fifteen samples of Laban made at home in three Omani regions were subjected to physical-chemical and microbiological analysis. Laban had an average titratable acidity, pH, fat, protein and total solids of 1.12%, 3.98, 1.I2%, 2. 11% and 6.29%, respectively. The microbial flora of traditional Omani laban was found to be predominantly mesophilic lactococci. and homofemenentative lactobacili. The mean Lactococci and lactobacilli counts were 1.3 x 10 8 and 2.4 x 10 6/ml respectively. The main microbial types involved in the manufacture of Omani laban were Lactoeoccus lactis ssp lactis. Lacrococcus locus ssp locus biov. Diacetylactis, Lactococcus lactis ssp, Cremoris. and Lactobacillus plantarum. Leuconostoc species were present in low proportion compared to other lactic acid bacteria. All Laban samples contained high yeast numbers and were highly contaminated with coliforms, and fecal coliforms.


2018 ◽  
Vol 6 (1-2) ◽  
pp. 50-56
Author(s):  
Judit Péter Szűcs ◽  
Ágnes Süli ◽  
Tímea Süli-Zakar ◽  
Elizabet Berecz ◽  
Máté Pék

The object of the trial was to study the effect of some lactic acid bacteria strains on the chemical composition, energy- and metabolisable protein (MP) content, microbiological characteristics and in-silo weight and dry matter losses of whole crop maize silages. The whole plant maize raw material was 32% DM, in soft cheddar stage of grain ripeness. It was ensiled in 4.2 litre capacity glass micro-size silos in 5 replicates /each treatment and stored on constant 25 °C room temperature on day 95. The average packing desity was 211kg DM/m3 The applied treatments: 1. Untreated control, 2. Enterococcus faecium 100.000 CFU/g FM, 3. Lactobacillus plantarum 50.000 CFU/g + Enterococcus faecium 50.000 CFU/g, 4. Lactococcus lactis 100.000 CFU/g, Lactobacillus plantarum 50.000 CFU + Lactococcus lactis 50.000 CFU/g, 6. Lactobacillus plantarum 100.000 CFU The main experiences are the following: Chemical composition of whole crop maize silages treated by lactic acid bacteria strains are significantly differed from the control in some cases on P 5% level but the nutritive value (energy and MP content) of silages did not change significantly compare to the control untreated silage. Number of yeast and mould CFU of control silage was the highest (4.5 x 104 CFU/g FM) among all kind of treated ones, which was significant on P 1% level. Weight loss and DM loss were lower in all of the lactic acid bacteria treated silages in general than it was measured in the control silage. Least weight loss and one-third of DM loss was detected in Lactobacillus plantarum 000 CFU/g treated silage among all kind of silages.  


Plant Disease ◽  
2017 ◽  
Vol 101 (1) ◽  
pp. 29-33 ◽  
Author(s):  
Jean M. Bonasera ◽  
Jo Ann E. Asselin ◽  
Steven V. Beer

Several members of the lactic acid bacteria group were isolated from diseased onion plants and bulbs. Based on growth characteristics and sequence analysis of 16S rRNA and rpoA genes, the strains were identified as Lactococcus lactis, Lactobacillus plantarum, and three species of Leuconostoc, i.e., citreum, mesenteroides, and pseudomesenteroides. Pathogenic potential to onion leaves and mature onion bulbs was assessed. L. plantarum and all three Leuconostoc species caused symptoms in both leaves and bulbs. L. lactis caused scale discoloration in bulbs but failed to cause lesions on leaves. Leuconostoc citreum caused bulb decay in 7 days at 18°C as well as 37°C. This is the first report of a group of gram-positive bacteria able to cause disease in onion leaves.


Food Research ◽  
2020 ◽  
Vol 4 (4) ◽  
pp. 1038-1044
Author(s):  
E. Zubaidah ◽  
I. Susanti ◽  
S.S. Yuwono ◽  
A.P. Rahayu ◽  
I. Srianta ◽  
...  

This research was aimed to study the effect of Lactobacillus plantarum and Leuconostoc mesenteroides starter cultures application in lower salt concentration fermentation on sauerkraut quality. Fresh cut cabbage was fermented with different starter cultures (L. plantarum, L. mesenteroides or the combination) at different lower salt concentration (0.5% or 1%) at 28oC for 5 days. The obtained sauerkrauts were subjected to evaluation of the quality i.e. total lactic acid bacteria, pH, total acidity, total phenolic content and DPPH scavenging activity analysis. The sulforaphane content analysis was performed by using LC-MS. The starter cultures increased total lactic acid bacteria, total acidity and decreased pH. L. mesenteroides resulted in the highest total phenolic content and the lowest IC50 value. Sauerkraut with the addition of L. mesenteroides contains sulforaphane higher 848.65 ng/g than that of control 776.47 ng/g. The results analysis of LC-MS also detected another compound, namely 2-phenethyl isothiocyanate, an antimicrobial compound. The sauerkraut is potential in functional food development with antiproliferative, antiinflammatory, antioxidant, and anti-cancer activities.


2004 ◽  
Vol 71 (2) ◽  
pp. 231-244 ◽  
Author(s):  
Cécile Callon ◽  
Liliane Millet ◽  
Marie-Christine Montel

The objective of this work was to describe the diversity of lactic acid bacteria in traditional raw milk Salers cheeses at the species and strain levels. The characterization of 381 strains isolated during ripening and various strain collections was investigated using physiological analysis and molecular techniques: Rep-PCR, species and genus specific amplifications and the sequence analysis of 16S rDNA for strain typing and taxonomic identification. The strains belonged to Lactobacillus plantarum, Lactobacillus paracasei, Lactococcus lactis, Lactococcus garviae, Enterococcus faecalis, Enterococcus faecium, Leuconostoc mesenteroides, Leuconostoc pseudomesenteroides, Streptococcus salivarius, Streptococcus millieri, Streptococcus macedonicus and Pediococcus pentosaceus. A wide phenotypic and genomic heterogeneity was observed within the different species (Lactobacillus plantarum, Lactobacillus paracasei and Leuconostoc mesenteroides) according to the origin and the time of ripening. The natural microflora was different from strain collection and each method must be combined to identify and characterize natural microflora. This study revealed the low selectivity of selective media used for the isolation of different groups of lactic acid bacteria except the Facultatively Heterofermentative lactobacilli medium selecting mesophile lactobacilli and SB medium selective for Enterococcus. The study reveals, for the first time, the microbial lactic acid bacteria community of Salers cheese and its diversity. A better knowledge of microbial flora will be useful to improve understanding of sensory quality of cheeses.


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