Interactions between Lactococcus lactis and Streptococcus thermophilus strains in Cheddar cheese processing conditions

2009 ◽  
Vol 19 (11) ◽  
pp. 669-674 ◽  
Author(s):  
C.P. Champagne ◽  
D. Gagnon ◽  
D. St-Gelais ◽  
J.C. Vuillemard
Keyword(s):  
Lactococcus Lactis ◽  
Cheddar Cheese ◽  
Streptococcus Thermophilus ◽  
Processing Conditions

scholarly journals Impact of Nisin and Nisin-Producing Lactococcus lactis ssp. lactis on Clostridium tyrobutyricum and Bacterial Ecosystem of Cheese Matrices

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 898
Author(s):  
Hebatoallah Hassan ◽  
Daniel St-Gelais ◽  
Ahmed Gomaa ◽  
Ismail Fliss
Keyword(s):  
Lactococcus Lactis ◽  
Cheddar Cheese ◽  
Economic Loss ◽  
Gas Production ◽  
Clostridium Tyrobutyricum ◽  
Nisin Production ◽  
Genus Clostridium ◽  
Milk Pasteurization ◽  
Cheese Slurry ◽  
Significant Economic Loss

Clostridium tyrobutyricum spores survive milk pasteurization and cause late blowing of cheeses and significant economic loss. The effectiveness of nisin-producing Lactococcus lactis ssp. lactis 32 as a protective strain for control the C. tyrobutyricum growth in Cheddar cheese slurry was compared to that of encapsulated nisin-A. The encapsulated nisin was more effective, with 1.0 log10 reductions of viable spores after one week at 30 °C and 4 °C. Spores were not detected for three weeks at 4 °C in cheese slurry made with 1.3% salt, or during week 2 with 2% salt. Gas production was observed after one week at 30 °C only in the control slurry made with 1.3% salt. In slurry made with the protective strain, the reduction in C. tyrobutyricum count was 0.6 log10 in the second week at 4 °C with both salt concentration. At 4 °C, nisin production started in week 2 and reached 97 µg/g after four weeks. Metabarcoding analysis targeting the sequencing of 16S rRNA revealed that the genus Lactococcus dominated for four weeks at 4 °C. In cheese slurry made with 2% salt, the relative abundance of the genus Clostridium decreased significantly in the presence of nisin or the protective strain. The results indicated that both strategies are able to control the growth of Clostridium development in Cheddar cheese slurries.

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.

Fate of Aflatoxin M1 in Cheddar Cheese and in Process Cheese Spread

1982 ◽  
Vol 45 (6) ◽  
pp. 549-552 ◽  
Author(s):  
ROBERT E. BRACKETT ◽  
ELMER H. MARTH
Keyword(s):  
Analytical Method ◽  
Cheddar Cheese ◽  
Aflatoxin M1 ◽  
Processing Conditions ◽  
Ripening Period ◽  
Process Cheese

Four batches of stirred-curd Cheddar cheese were prepared, using milk which was naturally contaminated with aflatoxin M1. This cheese was analyzed for aflatoxin M1 content at intervals while the cheese ripened for about 1 year. Levels of aflatoxin M1 detected in cheese started low, increased and then leveled off for the remainder of the ripening period. This cheese was used to make process cheese spread. The spread appeared to contain as much or more aflatoxin M1 as the cheese from which it was made. The aflatoxin M1 content of cheese spread appeared to increase, and then return to near original levels during storage at 7°C. Contaminated Cheddar cheese was treated with heat (90°C for 20 min), emulsifying salt (5% Na2HPO4) or both to determine the influence of processing conditions on aflatoxin M1. Samples treated with emulsifying salt or heat showed an increase in aflatoxin M1 content but not as much as when samples were treated with both. The apparent increased in aflatoxin M1 content in natural cheese and in process cheese spread may be associated with greater recovery of toxin by the analytical method as cheese ripens or is treated to make the process cheese spread.

scholarly journals Unleashing Natural Competence in Lactococcus lactis by Induction of the Competence Regulator ComX

2017 ◽  
Vol 83 (20) ◽  
Author(s):  
Joyce Mulder ◽  
Michiel Wels ◽  
Oscar P. Kuipers ◽  
Michiel Kleerebezem ◽  
Peter A. Bron
Keyword(s):  
Lactococcus Lactis ◽  
Genetic Manipulation ◽  
Bacterial Species ◽  
Streptococcus Thermophilus ◽  
Starter Cultures ◽  
Natural Competence ◽  
Content Type ◽  
Competence Gene ◽  
Gene Sets ◽  
Novel Traits

ABSTRACT In biotechnological workhorses like Streptococcus thermophilus and Bacillus subtilis, natural competence can be induced, which facilitates genetic manipulation of these microbes. However, in strains of the important dairy starter Lactococcus lactis, natural competence has not been established to date. However, in silico analysis of the complete genome sequences of 43 L. lactis strains revealed complete late competence gene sets in 2 L. lactis subsp. cremoris strains (KW2 and KW10) and at least 10 L. lactis subsp. lactis strains, including the model strain IL1403 and the plant-derived strain KF147. The remainder of the strains, including all dairy isolates, displayed genomic decay in one or more of the late competence genes. Nisin-controlled expression of the competence regulator comX in L. lactis subsp. lactis KF147 resulted in the induction of expression of the canonical competence regulon and elicited a state of natural competence in this strain. In contrast, comX expression in L. lactis NZ9000, which was predicted to encode an incomplete competence gene set, failed to induce natural competence. Moreover, mutagenesis of the comEA-EC operon in strain KF147 abolished the comX-driven natural competence, underlining the involvement of the competence machinery. Finally, introduction of nisin-inducible comX expression into nisRK-harboring derivatives of strains IL1403 and KW2 allowed the induction of natural competence in these strains also, expanding this phenotype to other L. lactis strains of both subspecies. IMPORTANCE Specific bacterial species are able to enter a state of natural competence in which DNA is taken up from the environment, allowing the introduction of novel traits. Strains of the species Lactococcus lactis are very important starter cultures for the fermentation of milk in the cheese production process, where these bacteria contribute to the flavor and texture of the end product. The activation of natural competence in this industrially relevant organism can accelerate research aiming to understand industrially relevant traits of these bacteria and can facilitate engineering strategies to harness the natural biodiversity of the species in optimized starter strains.

Functional Analysis of Glycosyltransferase Genes from Lactococcus lactis and Other Gram-Positive Cocci: Complementation, Expression, and Diversity

1999 ◽  
Vol 181 (20) ◽  
pp. 6347-6353 ◽  
Author(s):  
Richard van Kranenburg ◽  
Harmjan R. Vos ◽  
Iris I. van Swam ◽  
Michiel Kleerebezem ◽  
Willem M. de Vos
Keyword(s):  
Lactococcus Lactis ◽  
Streptococcus Thermophilus ◽  
Gene Clusters ◽  
Second Step ◽  
Chemical Compositions ◽  
Erythromycin Resistance ◽  
Gram Positive ◽  
Group Iii ◽  
Group I ◽  
Gram Positive Cocci

ABSTRACT Sixteen exopolysaccharide (EPS)-producing Lactococcus lactis strains were analyzed for the chemical compositions of their EPSs and the locations, sequences, and organization of theeps genes involved in EPS biosynthesis. This allowed the grouping of these strains into three major groups, representatives of which were studied in detail. Previously, we have characterized theeps gene cluster of strain NIZO B40 (group I) and determined the function of three of its glycosyltransferase (GTF) genes. Fragments of the eps gene clusters of strains NIZO B35 (group II) and NIZO B891 (group III) were cloned, and these encoded the NIZO B35 priming galactosyltransferase, the NIZO B891 priming glucosyltransferase, and the NIZO B891 galactosyltransferase involved in the second step of repeating-unit synthesis. The NIZO B40 priming glucosyltransferase gene epsD was replaced with an erythromycin resistance gene, and this resulted in loss of EPS production. This epsD deletion was complemented with priming GTF genes from gram-positive organisms with known function and substrate specificity. Although no EPS production was found with priming galactosyltransferase genes from L. lactis orStreptococcus thermophilus, complementation with priming glucosyltransferase genes involved in L. lactis EPS andStreptococcus pneumoniae capsule biosynthesis could completely restore or even increase EPS production in L. lactis.

scholarly journals Peptide Accumulation and Bitterness in Cheddar Cheese Made Using Single-Strain Lactococcus lactis Starters with Distinct Proteinase Specificities

1998 ◽  
Vol 81 (2) ◽  
pp. 327-337 ◽  
Author(s):  
Jeffery R. Broadbent ◽  
Marie Strickland ◽  
Bart C. Weimer ◽  
Mark E. Johnson ◽  
James L. Steele
Keyword(s):  
Lactococcus Lactis ◽  
Cheddar Cheese ◽  
Single Strain

scholarly journals Contribution of Lactococcus lactis Cell Envelope Proteinase Specificity to Peptide Accumulation and Bitterness in Reduced-Fat Cheddar Cheese

2002 ◽  
Vol 68 (4) ◽  
pp. 1778-1785 ◽  
Author(s):  
Jeffery R. Broadbent ◽  
Mary Barnes ◽  
Charlotte Brennand ◽  
Marie Strickland ◽  
Kristen Houck ◽  
...  
Keyword(s):  
Lactococcus Lactis ◽  
Cell Envelope ◽  
Cheddar Cheese ◽  
Gene Replacement ◽  
Reversed Phase ◽  
Reduced Fat ◽  
Key Factor ◽  
Industrial Strains ◽  
Group A ◽  
Or Gene

ABSTRACT Bitterness is a flavor defect in Cheddar cheese that limits consumer acceptance, and specificity of the Lactococcus lactis extracellular proteinase (lactocepin) is widely believed to be a key factor in the development of bitter cheese. To better define the contribution of this enzyme to bitterness, we investigated peptide accumulation and bitterness in 50% reduced-fat Cheddar cheese manufactured with single isogenic strains of Lactococcus lactis as the only starter. Four isogens were developed for the study; one was lactocepin negative, and the others produced a lactocepin with group a, e, or h specificity. Analysis of cheese aqueous extracts by reversed-phase high-pressure liquid chromatography confirmed that accumulation of αS1-casein (f 1-23)-derived peptides f 1-9, f 1-13, f 1-16, and f 1-17 in cheese was directly influenced by lactocepin specificity. Trained sensory panelists demonstrated that Cheddar cheese made with isogenic starters that produced group a, e, or h lactocepin was significantly more bitter than cheese made with a proteinase-negative isogen and that propensity for bitterness was highest in cells that produced group h lactocepin. These results confirm the role of starter proteinase in bitterness and suggest that the propensity of some industrial strains for production of the bitter flavor defect in cheese could be altered by proteinase gene exchange or gene replacement.

scholarly journals Importância das Bactérias Ácido Láticas e não Starter (NSLAB) na Tecnologia de Produção dos Derivados Lácteos

2020 ◽  
Vol 24 (4) ◽  
pp. 348-352
Author(s):  
Maria Tereza Pereira ◽  
Elsa Helena Walter de Santana ◽  
Joice Sifuentes dos Santos
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactococcus Lactis ◽  
Lactobacillus Casei ◽  
Streptococcus Thermophilus ◽  
Raw Milk ◽  
Fermented Milk ◽  
Starter Cultures ◽  
Bacillus Spp ◽  
Lactobacillus Spp

Produtos lácteos fermentados contêm bactérias ácido lácticas (BAL), naturalmente presentes ou adicionadas na matriz láctea como culturas iniciadoras (starters), contribuindo com aroma, textura, valor nutricional e segurança microbiológica. Lactobacillus spp., Streptococcus spp., Lactococcus spp. e Leuconostoc spp. são utilizados como culturas starters em laticínios. As BAL podem ser classificadas em mesofílicas (ex Lactococcus lactis) e termofílicas (ex Streptococcus thermophilus), e de acordo com seus metabólitos de fermentação em homofermentativas (ácido lático) e heterofermentativas (ácido lático, dióxido de carbono, diacetil e outros compostos flavorizantes). Entre as BAL há um grupo de bactérias lácticas que não fazem parte da cultura láctica (non starter lactic acid bacteria - NSLAB), que são oriundas do leite cru, do ambiente de ordenha ou da indústria formando biofilmes. As NSLAB são representadas por espécies heterofermentativas de lactobacilos mesofílicos como Lactobacillus casei spp., L. paracasei spp., L. rhamnosus spp. e L. plantarum spp., e ainda por Pediococcus spp., Leuconostoc spp. e Micrococcus spp. NSLAB termoduricas como Bacillus spp. também são relatadas. As NSLAB em queijos podem ajudar a desenvolver sabor e aroma, porém também são associadas aos defeitos em queijos e leites fermentados. Problemas como odores estranhos, sabor amargo ou muito ácido, perda de viscosidade, perda de coloração, estufamento e formação de gás são associados com a presença e contaminação por NSLAB. Assim, as BAL são importantes micro-organismos na indústria láctea, garantindo sabores e aromas aos derivados. Já a presença de NSLAB podem ser associados com defeitos em queijos e leites fermentados, sendo um problema na indústria beneficiadora.   Palavras-chave: Característica Sensorial. Leites Fermentados. Queijo. Textura.                       Abstract Fermented dairy products contain acid bacteria (BAL) naturally present or added to the dairy matrix as starter cultures (starters), contributing to aroma, texture, nutritional value and microbiological safety. Lactobacillus spp., Streptococcus spp., Lactococcus spp. and Leuconostoc spp. are used as starter dairy crops. As BAL it can be classified as mesophilic (ex: Lactococcus lactis) and thermophilic (ex: Streptococcus thermophilus), and agree with its fermentation metabolites in homofermentative (lactic acid) and heterofermentative (lactic acid, carbon dioxide, diacetyl and other flavorings). Among the BAL, there is a group of lactic bacteria that are not part of the dairy culture (non-initiating lactic acid bacteria - NSLAB) that originate from raw milk, the milking environment or the biofilm-forming industry. NSLAB is represented by heterofermentative species of mesophilic lactobacilli such as Lactobacillus casei spp., L. paracasei spp., L. rhamnosus spp. and L. plantarum spp., and also by Pediococcus spp., Leuconostoc spp. and Micrococcus spp. Termoduric NSLAB such as Bacillus spp. are also related. NSLAB in cheeses may help develop flavor and aroma, and they are also associated with defects in fermented cheeses and milks. Problems such as strange odors, bitter or very acidic taste, loss of viscosity, loss of color, establishment and gas training are associated with the presence and contamination by NSLAB. Thus,  BALs are important microorganisms in the dairy industry, contributing to the dairy flavors and aromas. The presence of NSLAB, on the other hand, can be associated with defects in fermented milk and cheese, being a problem in the processing industry.   Keywords: Cheese. Fermented Milk. Sensory Characteristic. Texture.

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