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 Exopolysaccharides Produced by Lactic Acid Bacteria: From Biosynthesis to Health-Promoting Properties

Foods ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 156
Author(s):  
Dominika Jurášková ◽  
Susana C. Ribeiro ◽  
Celia C. G. Silva
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Meat Products ◽  
Fermented Foods ◽  
Cholesterol Lowering ◽  
Beneficial Effects ◽  
Composition And Structure ◽  
Health Promoting

The production of exopolysaccharides (EPS) by lactic acid bacteria (LAB) has attracted particular interest in the food industry. EPS can be considered as natural biothickeners as they are produced in situ by LAB and improve the rheological properties of fermented foods. Moreover, much research has been conducted on the beneficial effects of EPS produced by LAB on modulating the gut microbiome and promoting health. The EPS, which varies widely in composition and structure, may have diverse health effects, such as glycemic control, calcium and magnesium absorption, cholesterol-lowering, anticarcinogenic, immunomodulatory, and antioxidant effects. In this article, the latest advances on structure, biosynthesis, and physicochemical properties of LAB-derived EPS are described in detail. This is followed by a summary of up-to-date methods used to detect, characterize and elucidate the structure of EPS produced by LAB. In addition, current strategies on the use of LAB-produced EPS in food products have been discussed, focusing on beneficial applications in dairy products, gluten-free bakery products, and low-fat meat products, as they positively influence the consistency, stability, and quality of the final product. Highlighting is also placed on reports of health-promoting effects, with particular emphasis on prebiotic, immunomodulatory, antioxidant, cholesterol-lowering, anti-biofilm, antimicrobial, anticancer, and drug-delivery activities.

scholarly journals Polyphasic Study of the Spatial Distribution of Microorganisms in Mexican Pozol, a Fermented Maize Dough, Demonstrates the Need for Cultivation-Independent Methods To Investigate Traditional Fermentations

1999 ◽  
Vol 65 (12) ◽  
pp. 5464-5473 ◽  
Author(s):  
Frédéric Ampe ◽  
Nabil ben Omar ◽  
Claire Moizan ◽  
Carmen Wacher ◽  
Jean-Pierre Guyot
Keyword(s):  
Lactic Acid ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Fermented Food ◽  
Fermented Foods ◽  
Product Analysis ◽  
Culture Independent ◽  
Gradient Gel Electrophoresis ◽  
Traditional Fermented Foods

ABSTRACT The distribution of microorganisms in pozol balls, a fermented maize dough, was investigated by a polyphasic approach in which we used both culture-dependent and culture-independent methods, including microbial enumeration, fermentation product analysis, quantification of microbial taxa with 16S rRNA-targeted oligonucleotide probes, determination of microbial fingerprints by denaturing gradient gel electrophoresis (DGGE), and 16S ribosomal DNA gene sequencing. Our results demonstrate that DGGE fingerprinting and rRNA quantification should allow workers to precisely and rapidly characterize the microbial assemblage in a spontaneous lactic acid fermented food. Lactic acid bacteria (LAB) accounted for 90 to 97% of the total active microflora; no streptococci were isolated, although members of the genus Streptococcus accounted for 25 to 50% of the microflora. Lactobacillus plantarum and Lactobacillus fermentum, together with members of the generaLeuconostoc and Weissella, were the other dominant organisms. The overall activity was more important at the periphery of a ball, where eucaryotes, enterobacteria, and bacterial exopolysacharide producers developed. Our results also showed that the metabolism of heterofermentative LAB was influenced in situ by the distribution of the LAB in the pozol ball, whereas homolactic fermentation was controlled primarily by sugar limitation. We propose that starch is first degraded by amylases from LAB and that the resulting sugars, together with the lactate produced, allow a secondary flora to develop in the presence of oxygen. Our results strongly suggest that cultivation-independent methods should be used to study traditional fermented foods.

Antimycotic and Antiaflatoxigenic Effect of Lactic Acid Bacteria: A Review†

1995 ◽  
Vol 58 (11) ◽  
pp. 1275-1280 ◽  
Author(s):  
HASSAN GOURAMA ◽  
LLOYD B. BULLERMAN
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactococcus Lactis ◽  
Health Hazard ◽  
Aflatoxin Production ◽  
Fermented Foods ◽  
Therapeutic Effects ◽  
Potential Health ◽  
Heat Stable ◽  
Potential Health Hazard

Lactic acid bacteria are extensively used in the fermentation of a wide variety of food products and are known for their preservative and therapeutic effects. Many lactic acid bacteria species have been reported to inactivate bacterial pathogens, and numerous antibacterial substances have been isolated. However, the antimycotic and antimycotoxigenic potential of lactic acid bacteria has still not been fully investigated. Fermented foods such as cheese can be contaminated by molds and mycotoxins. Mold causes spoilage and renders the product unusable for consumption, and the presence of mycotoxins presents a potential health hazard. A limited number of reports have shown that lactic acid bacteria affect mold growth and aflatoxin production. Although numerous lactic acid bacteria such as Lactobacillus spp. were found to inhibit aflatoxin biosynthesis, other lactic bacteria such as Lactococcus lactis were found to stimulate aflatoxin production. The morphology of lactic acid bacteria cells has also been found to be affected by the presence of fungal mycelia and aflatoxin. Lactococcus lactis cells became larger and formed long chains in the presence of Aspergillus flavus and aflatoxins. Numerous investigations reported that low pH, depletion of nutrients, and microbial competition do not explain the reason for aflatoxin inhibition. Some investigators suggested that the inhibition of aflatoxin is due to lactic acid and/or lactic acid bacteria metabolites. These metabolites have been reported to be heat-stable low-molecular-weight compounds.

Sequencing of the Tyrosine Decarboxylase Cluster of Lactococcus lactis IPLA 655 and the Development of a PCR Method for Detecting Tyrosine Decarboxylating Lactic Acid Bacteria

2004 ◽  
Vol 67 (11) ◽  
pp. 2521-2529 ◽  
Author(s):  
MARÍA FERNÁNDEZ ◽  
DANIEL M. LINARES ◽  
MIGUEL A. ALVAREZ
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactococcus Lactis ◽  
Trna Synthetase ◽  
Fermented Foods ◽  
Tyrosine Decarboxylase ◽  
Molecular Tools ◽  
Genes Encoding ◽  
Pcr Method ◽  
Lactis Strain

The enzymatic decarboxylation of tyrosine produces tyramine, the most abundant biogenic amine in dairy products—especially in cheeses. The screening of lactic acid bacteria isolated from different artisanal cheeses and a number of microbial collections identified 22 tyramine-producing strains belonging to different genera. The Lactococcus lactis strain IPLA 655 was selected, and the genes encoding a putative tyrosyl tRNA synthetase, a tyrosine decarboxylase (tdcA), and a tyrosine-tyramine antiporter, found together as a cluster, were sequenced. The disruption of tdcA yielded a strain unable to produce tyramine. Comparison of the L. lactis IPLA 655 tdcA gene with database tdcA sequences led to the design of two primers for use in a PCR method that identified potential tyramine-producing strains. The proposed method can use purified DNA, isolated colonies, milk, curd, and even cheese as a template. Molecular tools for the rapid detection of tyramine-producing bacteria at any time during the fermentation process could help prevent tyramine accumulation in fermented foods. The proposed technique could be of great use to the food industry.

scholarly journals Heterologous Expression of the Lactococcus lactis Bacteriocin, Nisin, in a Dairy Enterococcus Strain

2002 ◽  
Vol 68 (7) ◽  
pp. 3392-3400 ◽  
Author(s):  
Haiping Li ◽  
Daniel J. O'Sullivan
Keyword(s):  
Signal Transduction ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Heterologous Expression ◽  
Lactococcus Lactis ◽  
Pcr Amplification ◽  
Northern Hybridization ◽  
Dose Dependent Fashion ◽  
Dose Dependent ◽  
Enterococcus Strain

ABSTRACT The bacteriocin nisin is produced only by some strains of Lactococcus lactis, and to date production in other lactic acid bacteria has not been achieved. Enterococcus sp. strain N12β is a nisin-immune transconjugant obtained from a nisin-producing donor (L. lactis ATCC 11454) and a dairy recipient (Enterococcus sp. strain S12β), but it does not produce nisin. In this study, using PCR amplification, we confirmed that the whole nisin operon is likely present in Enterococcus sp. strain N12β. Northern hybridization of total RNA from strain N12β with a nisA probe and the results of reverse transcriptase PCR showed the lack of nisA transcription in this strain. However, nisA transcription was partially restored in strain N12β upon growth in the presence of exogenous nisin, and the nisA transcription signal was intensified after an increase in the external nisin level. Furthermore, bioassays showed that active nisin was produced in a dose-dependent fashion by strain N12β following induction by exogenous nisin. These results indicated that expression of the nisin genes in Enterococcus sp. strain N12β depended on autoinduction via signal transduction. However, the amount of external inducing signal required was significantly greater than the amount needed for autoinduction in L. lactis.

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 In Situ Production of Exopolysaccharides during Sourdough Fermentation by Cereal and Intestinal Isolates of Lactic Acid Bacteria

2003 ◽  
Vol 69 (2) ◽  
pp. 945-952 ◽  
Author(s):  
Markus Tieking ◽  
Maher Korakli ◽  
Matthias A. Ehrmann ◽  
Michael G. Gänzle ◽  
Rudi F. Vogel
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactobacillus Reuteri ◽  
Pcr Primers ◽  
Sole Source ◽  
Amino Acid Sequences ◽  
Type Ii ◽  
Bread Production ◽  
In Situ Production

ABSTRACT EPS formed by lactobacilli in situ during sourdough fermentation may replace hydrocolloids currently used as texturizing, antistaling, or prebiotic additives in bread production. In this study, a screening of >100 strains of cereal-associated and intestinal lactic acid bacteria was performed for the production of exopolysaccharides (EPS) from sucrose. Fifteen strains produced fructan, and four strains produced glucan. It was remarkable that formation of glucan and fructan was most frequently found in intestinal isolates and strains of the species Lactobacillus reuteri, Lactobacillus pontis, and Lactobacillus frumenti from type II sourdoughs. By the use of PCR primers derived from conserved amino acid sequences of bacterial levansucrase genes, it was shown that 6 of the 15 fructan-producing lactobacilli and none of 20 glucan producers or EPS-negative strains carried a levansucrase gene. In sourdough fermentations, it was determined whether those strains producing EPS in MRS medium modified as described by Stolz et al. (37) and containing 100 g of sucrose liter−1 as the sole source of carbon also produce the same EPS from sucrose during sourdough fermentation in the presence of 12% sucrose. For all six EPS-producing strains evaluated in sourdough fermentations, in situ production of EPS at levels ranging from 0.5 to 2 g/kg of flour was demonstrated. Production of EPS from sucrose is a metabolic activity that is widespread among sourdough lactic acid bacteria. Thus, the use of these organisms in bread production may allow the replacement of additives.

scholarly journals Complete Genome Sequences of 28 Lactococcal Bacteriophages Isolated from Failed Dairy Fermentation Processes

2020 ◽  
Vol 9 (12) ◽  
Author(s):  
Barbara Marcelli ◽  
Anne de Jong ◽  
Thomas Janzen ◽  
Mariela Serrano ◽  
Jan Kok ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacterium ◽  
Lactococcus Lactis ◽  
Complete Genome ◽  
Fermented Foods ◽  
Genome Sequences ◽  
Content Type ◽  
Fermentation Processes ◽  
The World ◽  
Dairy Fermentation

Lactococcus lactis is a Gram-positive lactic acid bacterium commonly used in the dairy industry for the production of fermented foods such as buttermilk and a wide variety of cheeses. Here, we report the complete genome sequences of 28 bacteriophages infecting different L. lactis industrial starter strains isolated from dairy plants throughout the world.

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