scholarly journals Genome Sequences of Lactococcus lactis MG1363 (Revised) and NZ9000 and Comparative Physiological Studies

2010 ◽  
Vol 192 (21) ◽  
pp. 5806-5812 ◽  
Author(s):  
Daniel M. Linares ◽  
Jan Kok ◽  
Bert Poolman
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Glucose Uptake ◽  
Lactococcus Lactis ◽  
Point Mutations ◽  
Genome Sequences ◽  
Sugar Fermentation ◽  
Sequencing Strategy ◽  
Physiological Studies ◽  
Transcriptomic Studies

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.

On the Microbiological Profile of Traditional Portuguese Sourdough

1999 ◽  
Vol 62 (12) ◽  
pp. 1416-1429 ◽  
Author(s):  
J. MIGUEL ROCHA ◽  
F. XAVIER MALCATA
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactococcus Lactis ◽  
Dominant Species ◽  
Geographic Locations ◽  
Microbiological Profile ◽  
Enterococcus Casseliflavus ◽  
Lactobacillus Spp

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.

scholarly journals EFFECT OF EXOPOLISACCHARIDES OF LACTIC ACID BACTERIA ON THE SYNTHESIS OF PROINFLAMMATORY CYTOKINES BY MACROPHAGIC MICE IN PHAGOCYTOSIS OF STAPHYLOCOCCUS AUREUS

2018 ◽  
pp. 67-71
Author(s):  
G. T. Uryadova ◽  
E. A. Gorelnikova ◽  
N. A. Fokina ◽  
A. S. Dolmashkina ◽  
L. V. Karpunina
Keyword(s):  
Staphylococcus Aureus ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactococcus Lactis ◽  
Inflammatory Cytokines ◽  
Proinflammatory Cytokines ◽  
Streptococcus Thermophilus ◽  
Ambiguous Effect ◽  
Pro Inflammatory Cytokines

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.

scholarly journals ISLpl1 Is a Functional IS30-Related Insertion Element in Lactobacillus plantarum That Is Also Found in Other Lactic Acid Bacteria

2003 ◽  
Vol 69 (10) ◽  
pp. 6032-6040 ◽  
Author(s):  
Hervé Nicoloff ◽  
Françoise Bringel
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactobacillus Plantarum ◽  
Point Mutations ◽  
Mobile Element ◽  
Distribution Data ◽  
Insertion Element ◽  
Is Element ◽  
Spontaneous Mutants ◽  
Related Element

ABSTRACT We describe the first functional insertion sequence (IS) element in Lactobacillus plantarum. ISLpl1, an IS30-related element, was found on the pLp3 plasmid in strain FB335. By selection of spontaneous mutants able to grow in the presence of uracil, it was demonstrated that the IS had transposed into the uracil phosphoribosyltransferase-encoding gene upp on the FB335 chromosome. The plasmid-carried IS element was also sequenced, and a second potential IS element was found: ISLpl2, an IS150-related element adjacent to ISLpl1. When Southern hybridization was used, the copy number and genome (plasmid versus chromosome) distribution data revealed different numbers and patterns of ISLpl1-related sequences in different L. plantarum strains as well as in Pediococcus strains. The ISLpl1 pattern changed over many generations of the strain L. plantarum NCIMB 1406. This finding strongly supports our hypothesis that ISLpl1 is a mobile element in L. plantarum. Database analysis revealed five quasi-identical ISLpl1 elements in Lactobacillus, Pediococcus, and Oenococcus strains. Three of these elements may be cryptic IS, since point mutations or 1-nucleotide deletions were found in their transposase-encoding genes. In some cases, ISLpl1 was linked to genes involved in cold shock adaptation, bacteriocin production, sugar utilization, or antibiotic resistance. ISLpl1 is transferred among lactic acid bacteria (LAB) and may play a role in LAB genome plasticity and adaptation to their environment.

scholarly journals Isolation, identification and antibiotic susceptibility of nis+ Lactococcus lactis from dairy and non-dairy sources

2013 ◽  
Vol 31 (No. 4) ◽  
pp. 323-331 ◽  
Author(s):  
P. Khemariya ◽  
S. Singh ◽  
G. Nath ◽  
A.K. Gulati
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Antimicrobial Agent ◽  
Lactococcus Lactis ◽  
Antibiotic Susceptibility ◽  
Pcr Amplification ◽  
Food Borne ◽  
Antibiotic Susceptibility Test ◽  
Different Types ◽  
Zones Of Inhibition

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.  

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 ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactobacillus Plantarum ◽  
Lactococcus Lactis ◽  
Leuconostoc Mesenteroides ◽  
Ftir Analysis ◽  
Molecular Weights ◽  
Molar Ratios ◽  
Monomer Composition ◽  
Ethanol Precipitation

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.

scholarly journals An Ecological Study of Lactic Acid Bacteria: Isolation of New Strains of Lactococcus Including Lactococcus lactis subspecies cremoris

1995 ◽  
Vol 78 (5) ◽  
pp. 1004-1017 ◽  
Author(s):  
Maysoon S. Salama ◽  
Tamara Musafija-Jeknic ◽  
William E. Sandine ◽  
Stephen J. Giovannoni
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactococcus Lactis ◽  
Ecological Study

Characterization of the Lactic Acid Bacteria in Ewe's Milk and Cheese from Northwest Argentina

2001 ◽  
Vol 64 (4) ◽  
pp. 559-563 ◽  
Author(s):  
ROXANA MEDINA ◽  
MARTA KATZ ◽  
SILVIA GONZALEZ ◽  
GUILLERMO OLIVER
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactococcus Lactis ◽  
Raw Milk ◽  
Northwest Argentina ◽  
Physiological And Biochemical Characteristics ◽  
Agar Media ◽  
Ewe's Milk ◽  
Physiological And Biochemical

Indigenous lactic acid bacteria in ewe's milk and artisanal cheese were studied in four samples of fresh raw milk and four 1-month-old cheeses from the provinces of northwest Argentina. Mean growth counts on M17, MRS, and MSE agar media did not show significant differences (P < 0.05) in raw milk and cheeses. Isolates of lactic acid bacteria from milk were identified as Enterococcus (48%), lactococci (14%), leuconostocs (8%), and lactobacilli (30%). All lactococci were identified as Lactococcus lactis (subsp. lactis and subsp. cremoris). Lactobacilli were identified as Lactobacillus plantarum (92%) and Lactobacillus acidophilus (8%). Enterococci (59%) and lactobacilli (41%) were isolated from cheeses. L. plantarum (93%), L. acidophilus (5%), and Lactobacillus casei (2%) were most frequently isolated. L. lactis subsp. lactis biovar diacetylactis strains were considered as fast acid producers. L. lactis subsp. cremoris strains were slow acid producers. L. plantarum and L. casei strains identified from the cheeses showed slow acid production. The majority of the lactobacilli and Lactococcus lactis strains utilized citrate and produced diacetyl and acetoin in milk. Enzyme activities (API-ZYM tests) of lactococci were low, but activities of L. plantarum strains were considerably higher. The predominance of L. plantarum in artisanal cheese is probably important in the ripening of these cheeses due to their physiological and biochemical characteristics.

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