β-glucooligosaccharides derived from barley β-glucan promote growth of lactic acid bacteria and enhance nisin Z secretion by Lactococcus lactis

LWT ◽  
2020 ◽  
Vol 122 ◽  
pp. 109014 ◽  
Author(s):  
Jong Min Lee ◽  
Won Je Jang ◽  
Eun-Woo Lee ◽  
In-Soo Kong
2021 ◽  
Vol 10 (1) ◽  
pp. 47
Author(s):  
Wanjin Qiao ◽  
Fulu Liu ◽  
Xing Wan ◽  
Yu Qiao ◽  
Ran Li ◽  
...  

Lactococcus lactis is a commonly used fermenting bacteria in cheese, beverages and meat products. Due to the lack of simplified chassis strains, it has not been widely used in the fields of synthetic biology. Thus, the construction of lactic acid bacteria chassis strains becomes more and more important. In this study, we performed whole genome sequencing, annotation and analysis of L. lactis N8. Based on the genome analysis, we found that L. lactis N8 contains two large plasmids, and the function prediction of the plasmids shows that some regions are related to carbohydrate transport/metabolism, multi-stress resistance and amino acid uptake. L. lactis N8 contains a total of seven prophage-related fragments and twelve genomic islands. A gene cluster encoding a hybrid NRPS–PKS system that was found in L. lactis N8 reveals that the strain has the potential to synthesize novel secondary metabolites. Furthermore, we have constructed a simplified genome chassis of L. lactis N8 and achieved the largest amount of deletion of L. lactis so far. Taken together, the present study offers further insights into the function and potential role of L. lactis N8 as a model strain of lactic acid bacteria and lays the foundation for its application in the field of synthetic biology.


2020 ◽  
Vol 9 (1) ◽  
pp. 65
Author(s):  
Stefano Nebbia ◽  
Cristina Lamberti ◽  
Giuliana Lo Bianco ◽  
Simona Cirrincione ◽  
Valerie Laroute ◽  
...  

Lactic acid bacteria (LAB) potential in the food industry and in the biotechnological sector is a well-established interest. LAB potential in counteracting especially food-borne infections has received growing attention, but despite being a road full of promises is yet poorly explored. Furthermore, the ability of LAB to produce antimicrobial compounds, both by ribosomal synthesis and by decrypting them from proteins, is of high value when considering the growing impact of multidrug resistant strains. The antimicrobial potential of 14 food-derived lactic acid bacteria strains has been investigated in this study. Among them, four strains were able to counteract Listeria monocytogenes growth: Lactococcus lactis SN12 and L. lactis SN17 by high lactic acid production, whereas L. lactis 41FLL3 and Lactobacillus sakei I151 by Nisin Z and Sakacin P production, respectively. Strains Lactococcus lactis MG1363, Lactobacillus rhamnosus 17D10 and Lactobacillus helveticus 4D5 were tested and selected for their potential attitude to hydrolyze caseins. All the strains were able to release bioactive peptides with already known antimicrobial, antihypertensive and opioid activities. These features render these strains or their bioactive molecules suitable for use in food as biocontrol agents, or as nutraceutical supplements to treat mild disorders such as moderate hypertension and children insomnia. These results highlight once again that LAB potential in ensuring food safety, food nutraceutical value and ultimately in favoring human health is still underexplored and underexploited.


2008 ◽  
Vol 71 (10) ◽  
pp. 2024-2029 ◽  
Author(s):  
PONGSAK RATTANACHAIKUNSOPON ◽  
PARICHAT PHUMKHACHORN

Lactic acid bacteria isolated from various Thai fermented foods were screened for the presence of nisin gene by using PCR with primers specific to nisin A structural gene. Only one strain, Lactococcus lactis subsp. lactis TFF 221, isolated from kung jom, a traditional shrimp paste, was found to carry a nisin gene. The TFF 221 nisin had antimicrobial activity against not only closely related lactic acid bacteria but also some foodborne pathogens. It was heat stable and inactivated by α-chymotrypsin and proteinase K. Some characteristics of TFF 221 nisin were found to be very similar to those of nisin A produced by Lactococcus lactis subsp. lactis NCDO 2111. Both of them had the same antimicrobial spectrum and MICs against all indicator bacteria. However, when assayed with indicator organisms, in all cases the TFF 221 nisin produced larger zones of inhibition in agar diffusion assays than the nisin A did. Sequencing of the TFF 221 nisin gene showed that it was the natural nisin variant, nisin Z, as indicated by the substitution of asparagine residue instead of histidine at position 27. The nisin determinant in strain TFF 221 was found to be located on a conjugative transposon residing in the chromosome. The ability of the nisin produced by L. lactis subsp. lactis TFF 221 to inhibit a wide range of foodborne pathogens may be useful in improving the food safety of the fermented product, especially in the Thai environment, which suffers from perennial problems of poor food hygiene.


1999 ◽  
Vol 62 (12) ◽  
pp. 1416-1429 ◽  
Author(s):  
J. MIGUEL ROCHA ◽  
F. XAVIER MALCATA

Traditional manufacture of bread from maize has been noted to play important roles from both economic and social standpoints; however, enforcement of increasingly strict hygiene standards requires thorough knowledge of the adventitious microbiota of the departing dough. To this goal, sourdough as well as maize and rye flours from several geographic locations and in two different periods within the agricultural year were assayed for their microbiota in sequential steps of quantification and identification. More than 400 strains were isolated and taxonomic differentiation between them was via Biomerieux API galleries (375 of which were successfully identified) following preliminary biochemical and morphological screening. The dominant groups were yeasts and lactic acid bacteria (LAB). The most frequently isolated yeasts were Saccharomyces cerevisiae and Candida pelliculosa. The most frequently isolated LAB were (heterofermentative) Leuconostoc spp. and (homo-fermentative) Lactobacillus spp.; L. brevis, L. curvatus, and L. lactis ssp. lactis were the dominant species for the Lactobacillus genera; Lactococcus lactis ssp. lactis for lactococci; Enterococcus casseliflavus, E. durans, and E. faecium for enterococci; and Streptococcus constellantus and S. equinus for streptococci.


Author(s):  
G. T. Uryadova ◽  
E. A. Gorelnikova ◽  
N. A. Fokina ◽  
A. S. Dolmashkina ◽  
L. V. Karpunina

Aim. Study of the effect of exopolysaccharides (EPS) of lactic acid cocci on cytokine activity of macrophages of mice with phagocytosis in vitro Staphylococcus aureus 209-P. Materials and methods. The EPS of Streptococcus thermophilus and Lactococcus lactis B-1662 was used in the work. At 13, 5 and 7, AMP and PMP were isolated and the phagocytosis process was modeled in vitro. After 30 minutes, 1, 6 and 24 hours, the content of pro-inflammatory cytokines IL-1a and TNF-a was determined. Results. EPSs had an ambiguous effect on the production of cytokines. The greatest effect on the synthesis was provided by EPS of S. thermophilus. Conclusion. The results of the study allow us to talk about the possibility of using EPS of S. thermophilus as a preventive immunomodulator for correction of the cytokine status of animals.


2010 ◽  
Vol 192 (21) ◽  
pp. 5806-5812 ◽  
Author(s):  
Daniel M. Linares ◽  
Jan Kok ◽  
Bert Poolman

ABSTRACT Lactococcus lactis NZ9000 and its parent MG1363 are the most commonly used lactic acid bacteria for expression and physiological studies. We noted unexpected but significant differences in the growth behaviors of both strains. We sequenced the entire genomes of the original NZ9000 and MG1363 strains using an ultradeep sequencing strategy. The analysis of the L. lactis NZ9000 genome yielded 79 differences, mostly point mutations, with the annotated genome sequence of L. lactis MG1363. Resequencing of the MG1363 strain revealed that 73 out of the 79 differences were due to errors in the published sequence. Comparative transcriptomic studies revealed several differences in the regulation of genes involved in sugar fermentation, which can be explained by two specific mutations in a region of the ptcC promoter with a key role in the regulation of cellobiose and glucose uptake.


2013 ◽  
Vol 31 (No. 4) ◽  
pp. 323-331 ◽  
Author(s):  
P. Khemariya ◽  
S. Singh ◽  
G. Nath ◽  
A.K. Gulati

Eight isolates of Lactococcus lactis subsp. lactis were isolated and identified by phenotypic and molecular characterisation out of 23 isolates of lactic acid bacteria (LAB) from different dairy and non-dairy sources. Out of eight strains, four were obtained from dairy and four from non-dairy sources. All eight strains of L. lactis subsp. lactis were able to produce zones of inhibition against the Lactobacillus acidophilus NCDC 015. The antimicrobial agent produced by the isolates inhibited the growth of a range of related lactic acid bacteria and certain Gram positive food-borne microorganisms. The antimicrobial agent, i.e. nisin, produced by the strains was confirmed by PCR amplification of nisin gene sequences of 174 bp size. Antibiotic susceptibility test to 21 different types of antibiotics was evaluated. All the isolates were resistant to fosfomycin, cefepime, amikacin, kanamycin, neomycin, nalidixic acid, pipemidic acid, norfloxacin, sulphadiazine, colistin, polymixin, teicoplanin, nystatin, and amphotericin B but susceptible to ampicillin, erythromycin, spiramycin, spectinomycin, ciprofloxacin, rifampicin, and trimethoprim.  


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.


1995 ◽  
Vol 78 (5) ◽  
pp. 1004-1017 ◽  
Author(s):  
Maysoon S. Salama ◽  
Tamara Musafija-Jeknic ◽  
William E. Sandine ◽  
Stephen J. Giovannoni

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