scholarly journals A Food-Grade Approach for Functional Analysis and Modification of Native Plasmids in Lactococcus lactis

2003 ◽  
Vol 69 (1) ◽  
pp. 702-706 ◽  
Author(s):  
Paul D. Cotter ◽  
Colin Hill ◽  
R. Paul Ross
Keyword(s):  
Functional Analysis ◽  
Lactic Acid ◽  
Lactococcus Lactis ◽  
Structural Proteins ◽  
Temperature Sensitive ◽  
Helper Plasmid ◽  
Food Grade ◽  
Lacticin 3147 ◽  
Grade Approach ◽  
Native Plasmid

ABSTRACT While plasmids from lactic acid bacteria possess many traits that are of industrial value, their exploitation is often frustrated by an inability to conduct food-grade engineering of native plasmids or to readily screen for their transfer. Here we describe a system that uses a RepA+ temperature-sensitive helper plasmid and a RepA− cloning vector to overcome these problems while maintaining the food-grade status of the native plasmid. This strategy was used to precisely delete ltnA1 alone, or in conjunction with ltnA2 (encoding the structural proteins of the lantibiotic lacticin 3147), from the native 60.2-kb plasmid pMRC01 and to select for the transfer of pMRC01 between Lactococcus lactis strains.

scholarly journals Riboflavin Production in Lactococcus lactis: Potential for In Situ Production of Vitamin-Enriched Foods

2004 ◽  
Vol 70 (10) ◽  
pp. 5769-5777 ◽  
Author(s):  
Catherine Burgess ◽  
Mary O'Connell-Motherway ◽  
Wilbert Sybesma ◽  
Jeroen Hugenholtz ◽  
Douwe van Sinderen
Keyword(s):  
Functional Analysis ◽  
Lactic Acid ◽  
Lactococcus Lactis ◽  
Regulatory Region ◽  
Northern Hybridization ◽  
Vitamin B ◽  
Fermented Foods ◽  
Riboflavin Production ◽  
In Situ Production

ABSTRACT This study describes the genetic analysis of the riboflavin (vitamin B2) biosynthetic (rib) operon in the lactic acid bacterium Lactococcus lactis subsp. cremoris strain NZ9000. Functional analysis of the genes of the L. lactis rib operon was performed by using complementation studies, as well as by deletion analysis. In addition, gene-specific genetic engineering was used to examine which genes of the rib operon need to be overexpressed in order to effect riboflavin overproduction. Transcriptional regulation of the L. lactis riboflavin biosynthetic process was investigated by using Northern hybridization and primer extension, as well as the analysis of roseoflavin-induced riboflavin-overproducing L. lactis isolates. The latter analysis revealed the presence of both nucleotide replacements and deletions in the regulatory region of the rib operon. The results presented here are an important step toward the development of fermented foods containing increased levels of riboflavin, produced in situ, thus negating the need for vitamin fortification.

scholarly journals Lactococcus lactis: LAB model organism for bacteria-mediated therapeutic strategies

2018 ◽  
pp. 1-10 ◽  
Author(s):  
Hanis Faudzi ◽  
Habibah Faroque ◽  
Suet-Lin Chia ◽  
Raha Abdul Rahim ◽  
Sarah Othman
Keyword(s):  
Lactic Acid ◽  
Lactococcus Lactis ◽  
Molecular Level ◽  
Model Organism ◽  
Therapeutic Strategies ◽  
Heterologous Proteins ◽  
Expression Systems ◽  
Food Grade ◽  
Vaccination Strategies ◽  
Disease Therapy

Lactococcus lactis is a well-characterized, food-grade lactic acid bacterium (LAB) with generally recognized as safe (GRAS) status. Better understanding of this bacterium at a molecular level has led to the development of unprecedented genetic tools that enable the expression of heterologous proteins. Subsequently, the ability of L. lactis to express and deliver these proteins to eukaryotic hosts presents a promising approach to achieve potent treatments for various diseases. Here, we have reviewed the characteristics of L. lactis and the expression systems established for this LAB model organism. We also described the experimental applications of L. lactis in disease therapy, especially its role as a vector in vaccination strategies.

Microcellular foaming of poly(lactic acid) branched with food‐grade chain extenders

2021 ◽  
Vol 138 (29) ◽  
pp. 50686
Author(s):  
Krishnaa B. Venkatesan ◽  
Sonal S. Karkhanis ◽  
Laurent M. Matuana
Keyword(s):  
Lactic Acid ◽  
Poly Lactic Acid ◽  
Food Grade ◽  
Microcellular Foaming ◽  
Chain Extenders

Food-grade lactic acid bacteria and probiotics as a potential protective tool against erythrotoxic dietary xenobiotics

2021 ◽  
Author(s):  
Paúl F. Cuevas-González ◽  
Audry Peredo-Lovillo ◽  
Cecilia Castro-López ◽  
Belinda Vallejo-Cordoba ◽  
Aarón F. González-Córdova ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Food Grade

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.

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