scholarly journals Presence of additional peptidases in Streptococcus thermophilus CNRZ 302 compared to Lactococcus lactis

1997 ◽  
Vol 82 (6) ◽  
pp. 695-704 ◽  
Author(s):  
F. Rul ◽  
V. Monnet
Keyword(s):  
Lactococcus Lactis ◽  
Streptococcus Thermophilus

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 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 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.

scholarly journals Unleashing natural competence inLactococcus lactisby induction of the competence regulator ComX

2017 ◽  
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 ◽  
Competence Gene ◽  
Gene Sets ◽  
Novel Traits ◽  
Derivatives Of

AbstractIn biotechnological work horses likeStreptococcus thermophilusandBacillus subtilisnatural competence can be induced, which facilitates genetic manipulation of these microbes. However, in strains of the important dairy starterLactococcus lactisnatural competence has not been established to date. However,in silicoanalysis of complete genome sequences of 43L. lactisstrains revealed complete late-competence gene-sets in 2L. lactissubspeciescremorisstrains (KW2 and KW10) and 8L. lactissubspecieslactisstrains, 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 regulatorcomXinL. lactissubsp.lactisKF147 resulted in the induction of expression of the canonical competence regulon, and elicited a state of natural competence in this strain. By contrast,comXexpression inL. lactisNZ9000, predicted to encode an incomplete competence gene-set, failed to induce natural competence. Moreover, mutagenesis of thecomEA-ECoperon in strain KF147, abolished thecomXdriven natural competence, underpinning the involvement of the competence machinery. Finally, introduction of nisin-induciblecomXexpression intonisRK-harboring derivatives of strains IL1403 and KW2 allowed the induction of natural competence also in these strains, expanding this phenotype to otherL. lactisstrains of both subspecies.Significance statementSpecific 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 speciesLactococcus lactisare 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.

scholarly journals ЕФЕКТИВНІСТЬ ПРЕПАРАТУ «СЕНОСІЛ» ДЛЯ КОНСЕРВУВАННЯ силосу

2016 ◽  
Vol 63 (3) ◽  
Author(s):  
Николай СЫЧЕВСЬКИЙ
Keyword(s):  
Lactococcus Lactis ◽  
Lactobacillus Acidophilus ◽  
Streptococcus Thermophilus ◽  
Propionibacterium Shermanii

Рішення національної програми підняття продуктивності і ефективності тваринництва неможливо без створення надійної кормової бази, яка багато в чому визначає якість і ціну виробленої продукції. У статті дана оцінка ефективності силосування кукурудзи гомо- і гетероферментативних молочнокислими і пропіоновокислі бактеріями Lactococcus lactis ssp. lactis biovar diacetilactis, Streptococcus thermophilus, Lactobacillus acidophilus, L. plantarum, L. brevis, L. rhamnosus, L. paracasei ssp. paracasei, Propionibacterium shermanii subsp. shermanii. Експериментально підтверджено високу біологічну активність виробничих штамів. Випробування бактеріальної закваски «Сеносіл» в умовах тваринницьких господарств показали, що її застосування гарантує зниження втрат сухих речовин і азоту; одержуваний силос багатий на вітаміни і органічними кислотами. Внесення закваски активно впливає на перебіг мікробіологічних і біохімічних процесів, пригнічуючи розвиток небажаної мікрофлори, сприяючи молочно-кислого бродіння і пригнічуючи маслянокислое. Змінилося співвідношення органічних кислот в силосі, в більш якісну сторону. Вміст молочної кислоти в кормі з закваскою було вище на 6,4%, і оцтової кислоти - на 26,5% в порівнянні з традиційно заготовленим силосом. Наявність масляної кислоти як в першому, так і другому зразках, не виявлено. В результаті більш швидкого підкислення в дослідному силосі пригнічується життєдіяльність небажаної мікрофлори, а саме дріжджів, цвілі і маслянокисле бактерій. Активна кислотність обробленого силосу перебувала на рівні 3,9 і забезпечувала кислотність, необхідну для придушення розвитку гнильної мікрофлори в кормі. Висока біологічна цінність корму забезпечується пробиотическими мікроорганізмами, що входять до складу закваски, і продуктами трансформації ними рослинної сировини. Чисельність молочнокислих мікроорганізмів на три порядки вище, ніж гнильних. Маслянокислі мікроорганізми в силосі з закваскою не виявлені. Силос, консервований з допомогою закваски, більшою мірою забезпечує кормові потреби тварин, сприяє нормалізації травлення тварин, підвищує засвоюваність корму, так рівень засвоюваності крохмалю в дослідному зразку був вище 12%, і показник вживання силосу на 6,5%, що, в кінцевому підсумку, впливає на ефективність роботи тваринницьких господарств. Біологічна і господарська оцінка силосів з кукурудзи з застосуванням розробленого препарату «Сеносіл», а також економічне обґрунтування доцільності використання даної закваски для силосування кормів у виробничих умовах показали її ефективність і затребуваність виробництвом. Технологія силосування кукурудзи з використанням бактеріальної закваски «Сеносіл» широко застосовується в ряді господарств України.

scholarly journals Film coatings based on exopolysaccharides of lactic acid bacteria and their use

2020 ◽  
Author(s):  
G. T. Uryadova ◽  
N. A. Fokina ◽  
L. V. Karpunina
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactococcus Lactis ◽  
Streptococcus Thermophilus ◽  
Film Coatings

It is shown that film coatings based on the exopolysaccharides of lactic acid bacteria Lactococcus lactis B-1662 and Streptococcus thermophilus contribute to the healing of burns in rats.

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