- Klíčová slova
- Lactiplantibacillus plantarum 299v,
- MeSH
- elektroforéza v agarovém gelu MeSH
- kokultivační techniky MeSH
- kultivační média MeSH
- kultivační techniky MeSH
- kysané mléčné výrobky MeSH
- Lactobacillus plantarum * fyziologie metabolismus růst a vývoj MeSH
- mléko MeSH
- probiotika terapeutické užití MeSH
- sójové mléko MeSH
Lactobacillus plantarum NMD-17 separated from koumiss could produce a bacteriocin named plantaricin MX against Gram-positive bacteria and Gram-negative bacteria. The bacteriocin synthesis of L. plantarum NMD-17 was remarkably induced in co-cultivation with Lactobacillus reuteri NMD-86 as the increase of cell numbers and AI-2 activity, and the expressions of luxS encoding signal AI-2 synthetase, plnB encoding histidine protein kinase, plnD encoding response regulator, and plnE and plnF encoding structural genes of bacteriocin were significantly upregulated in co-cultivation, showing that the bacteriocin synthesis of L. plantarum NMD-17 in co-cultivation may be regulated by LuxS/AI-2-mediated quorum sensing system. In order to further demonstrate the role of LuxS/AI-2-mediated quorum sensing system in the bacteriocin synthesis of L. plantarum NMD-17, plasmids pUC18 and pMD18-T simple were used as the skeleton to construct the suicide plasmids pUC18-UF-tet-DF and pMD18-T simple-plnB-tet-plnD for luxS and plnB-plnD gene deletion, respectively. luxS and plnB-plnD gene knockout mutants were successfully obtained by homologous recombination. luxS gene knockout mutant lost its AI-2 synthesis ability, suggesting that LuxS protein encoded by luxS gene is key enzyme for AI-2 synthesis. plnB-plnD gene knockout mutant lost the ability to synthesize bacteriocin against Salmonella typhimurium ATCC14028, indicating that plnB-plnD gene was a necessary gene for bacteriocin synthesis of L. plantarum NMD-17. Bacteriocin synthesis, cell numbers, and AI-2 activity of luxS or plnB-plnD gene knockout mutants in co-cultivation with L. reuteri NMD-86 were obviously lower than those of wild-type strain in co-cultivation at 6-9 h (P < 0.01). The results showed that LuxS/AI-2-mediated quorum sensing system played an important role in the bacteriocin synthesis of L. plantarum NMD-17 in co-cultivation.
Výskum probiotík pre akvakultúru je v ranom štádiu a pre ich implementáciu je potrebné vykonať ešte množstvo experimentov. Laktiplantibacily patria medzi mikroorganizmy, ktoré sa najčastejšie používajú na prípravu probiotických preparátov. Doterajšie výsledky nie sú postačujúce, práve preto sú potrebné ďalšie štúdie. Výber probiotík pre akvakultúru a ich vývoj pre komerčné využitie v akvakultúre je mnohostupňový a multidisciplinárny proces vyžadujúci si v prvej etape základný a neskôr aj aplikovaný výskum a posúdenie jeho použitia v praxi. Cieľom štúdie bolo pripraviť probiotické krmivo pre ryby s využitím pomocných látok a následne sledovať prežívateľnosť probiotických bakteriálnych buniek v krmive počas 9-mesačného skladovania pri chladničkovej (4 °C) a izbovej teplote (22 °C). Na prípravu krmiva bol použitý kmeň Lactobacillus plantarum R2 Biocenol™ (CCM 8674) (podľa novej taxonómie Lactiplantibacillus plantarum), potenciálne využiteľný pre probiotické účely v akvakultúre. Lepšia prežívateľnosť probiotických bakteriálnych buniek bola zaznamenaná vo vzorkách krmiva A (Aquatex 41 HMD) v porovnaní so vzorkami probiotických peliet B (Inicio 918-2). Keďže oxidácia mastných kyselín v krmive ovplyvňuje nutričnú kvalitu jednotlivých komponentov krmiva, predpokladáme, že vyššie množstvo oleja v krmive B negatívne ovplyvnilo prežívateľnosť probiotických bakteriálnych buniek. Najvyššie počty životaschopných probiotických baktérií boli zaznamenané pri 4 °C skladovania krmiva. Po 9 mesiacoch skladovania pri chladničkovej teplote počty laktiplantibacilov vo vzorkách krmiva A klesli z hodnoty 7,30 log10KTJ/g na počet 5,57 log10KTJ/g. Teplota je považovaná za rozhodujúci faktor ovplyvňujúci životaschopnosť a prežívateľnosť probiotických baktérií počas doby skladovania.
Research in probiotics for aquaculture is at an early stage of development and much work is still needed. Lactiplantibacilli belong to the microorganisms most frequently used to prepare the probiotics. The available information is inconclusive, since few experiments with sufficiently robust design have been conducted to permit critical evaluation. The development of probiotics applicable to commercial use in aquaculture is a multistep and multidisciplinary process requiring both empirical and fundamental research, full-scale trials, and an economic assessment of its use. The aim of the study was to prepare a probiotic aquafeed via excipients and subsequently to observe the survival of probiotic bacterial cells in the feed during the nine months storage period at a refrigerator (4 °C) or room temperature (22 °C). The strain Lactobacillus plantarum R2 Biocenol™ (CCM 8674) (according to the new taxonomy Lactiplantibacillus plantarum), potentially usable as a probiotic in aquaculture, was administered to prepare the aquafeed. Better survival of probiotic bacterial cells was recorded in a samples of pellets A (Aquatex 41 HMD) compared to the samples of probiotic pellets B (Inicio 918-2). Since oxidation of fatty acids in feed affects the nutritional quality of individual feed components, we assume that higher amounts of oil in feed B negatively affected the survival of probiotic bacterial cells. The highest numbers of viable probiotic bacteria cells were recorded at 4 °C storage of probiotic feed samples. The number of lactiplantibacilli dropped from 7.30 log10CFU . g–1 to 5.57 log10CFU . g–1 after the nine months storage period of feed samples A at 4 °C. Temperature is considered as a critical factor influencing probiotic viability and survival during storage period.
A bacteriocin termed plantaricin MX with a broad antimicrobial spectrum was produced by Lactobacillus plantarum NMD-17, which was isolated from Inner Mongolia traditional koumiss of china. Among 300 strains of lactic acid bacteria (LAB) belonging to the genera Lactococcus, Lactobacillus, Streptococcus, Leuconostoc, and Enterococcus, five strains including Lactobacillus reuteri NMD-86, Lactobacillus helveticus NMD-137, Lactococcus lactis NMD-152, Enterococcus faecalis NMD-178, and Enterococcus faecium NMD-219 were revealed to significantly induce the bacteriocin synthesis and greatly increase the cell numbers of Lactobacillus plantarum NMD-17 and activity of AI-2 signaling molecule. Bacteriocin synthesis was not increased by cell-free supernatants and autoclaved cultures of inducing strains, demonstrating that intact cells of inducing strains were essential to the induction of bacteriocin synthesis. The existence of bacteriocin structural plnEF genes and the plnD and luxS genes involved in quorum sensing was confirmed by PCR, and the presence of plnB gene encoding histidine protein kinase was determined by single oligonucleotide nested PCR (Son-PCR). Quantitative real-time PCR demonstrated that plnB, plnD, luxS, plnE, and plnF genes of L. plantarum NMD-17 were upregulated significantly (P < 0.01) in co-cultivation with L. reuteri NMD-86. The results showed that the bacteriocin synthesis of L. plantarum NMD-17 in co-cultivation might have a close relationship with LuxS-mediated quorum sensing system.
- MeSH
- bakteriální proteiny * genetika MeSH
- bakteriociny * genetika MeSH
- kumys * mikrobiologie MeSH
- Lactobacillales * fyziologie MeSH
- Lactobacillus plantarum * genetika MeSH
- lyasy štěpící vazby C-S * genetika MeSH
- mikrobiální interakce * fyziologie MeSH
- quorum sensing genetika MeSH
- Publikační typ
- časopisecké články MeSH
Clostridium perfringens forms biofilms and spores that are a source of food contamination. In this study, the antibacterial activities of Lactobacillus plantarum culture supernatants (LP-S), LP-S fractions, and the plant-derived compound epigallocatechin gallate (EG) were evaluated. Specifically, their effects on the viability and biofilm-forming ability of C. perfringens were assessed. Moreover, the expression of quorum sensing-regulated genes associated with the pathogenesis of this microorganism and that of genes involved in biofilm formation was also investigated. The results showed that both EG and the LP-S exerted bactericidal activity against all C. perfringens strains tested. The minimal bactericidal concentration (MBC) of EG was 75 µg/mL for all strains but ranged from 61 to 121 µg of total protein per mL for LP-S. EG exerted only minor effects on biofilm formation, whereas LP-S, particularly its 10 and 30 K fractions, significantly reduced the biofilm-forming ability of all the strains. The antibiofilm activity of LP-S was lost following preincubation with proteases, suggesting that it was mediated by a proteinaceous molecule. The treatment of C. perfringens with either EG or LP-S did not change the transcript levels of two CpAL (C. perfringens quorum-sensing Agr-like system)-related genes, agrB and agrD, which are known to be involved in the regulation of biofilms, suggesting that LP-S exerted its biofilm inhibitory activity downstream of CpAL signaling. In summary, we demonstrated the bactericidal activity of EG and LP-S against C. perfringens and antibiofilm activity of LP-S at a subinhibitory dose. Our results suggested that these compounds can be further explored for food safety applications to control agents such as C. perfringens.
Here, we report on the biochemical characterization of a new glycosylated bacteriocin (glycocin), ASM1, produced by Lactobacillus plantarum A-1 and analysis of the A-1 bacteriocinogenic genes. ASM1 is 43 amino acids in length with Ser18-O- and Cys43-S-linked N-acetylglucosamine moieties that are essential for its inhibitory activity. Its only close homologue, glycocin F (GccF), has five amino acid substitutions all residing in the flexible C-terminal 'tail' and a lower IC50 (0.9 nm) compared to that of ASM1 (1.5 nm). Asm/gcc genes share the same organization (asmH← →asmABCDE→F), and the asm genes reside on an 11 905-bp plasmid dedicated to ASM1 production. The A-1 genome also harbors a gene encoding a 'rare' bactofencin-type bacteriocin. As more examples of prokaryote S-GlcNAcylation are discovered, the functions of this modification may be understood.
- MeSH
- bakteriální geny genetika MeSH
- bakteriociny chemie genetika metabolismus MeSH
- fylogeneze MeSH
- glykosylace MeSH
- Lactobacillus plantarum chemie genetika MeSH
- novobiocin MeSH
- plazmidy genetika MeSH
- sekvence aminokyselin MeSH
- sekvence nukleotidů MeSH
- sekvenční analýza DNA MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The aim of the present study was to develop an ion-selective electrode method for the continuous determination of the intracellular pH in Lactobacillus plantarum using a small-scale bioreactor. This method employed a salicylate-selective electrode basing on the distribution of salicylic acid across the cytoplasmic membrane. This developed electrode responded to salicylate concentrations above 20 μmol/L with a Nernstian sensitivity. The energized and concentrated cells were added into a thermostated small-scale bioreactor that contained the salicylate anions dissolved in a 100 mmol/L potassium phosphate buffer at different pH values. The changes in salicylate concentration that occurred in the medium containing bacterial suspension were measured as a voltage change. The cells of Lactobacillus plantarum showed maintenance of pH homeostasis at the studied pH ranging from 4.0 to 7.0, and they kept a neutral intracellular pH up to 5.8. The simplicity of the measuring preparation and the relatively low cellular concentration, as well as the advantages of the small-scale bioreactor, lead us to believe that the described method can facilitate the study of the physicochemical factors on the intracellular pH of lactic acid bacteria using a single pH probe in one method.
BACKGROUND: Chronic undernutrition leads to growth hormone resistance and poor growth in children, which has been shown to be modulated by microbiota. We studied whether Lactobacillus fermentum CECT5716 (Lf CECT5716), isolated from mother's breast milk, could promote juvenile growth through the modulation of lipid absorption in a model of starvation. METHODS: Germ-free (GF) Drosophila melanogaster larvae were inoculated with Lf CECT5716 in conditions of undernutrition with and without infant formula. The impact of Lf CECT5716 on larval growth was assessed 7 days after egg laying (AED) by measuring the larval size and on maturation by measuring the emergence of pupae during 21 days AED. For lipid absorption test, Caco2/TC7 intestinal cells were incubated with Lf CECT5716 and challenged with mixed lipid micelles. RESULTS: The mono-associated larvae with Lf CECT5716 were significantly longer than GF larvae (3.7 vs 2.5 mm; p < 0.0001). The effect was maintained when Lf CECT5716 was added to the infant formula. The maturation time of larvae was accelerated by Lf CECT5716 (12 vs 13.2 days; p = 0.01). Lf CECT5716 did not have significant impact on lipid absorption in Caco2/TC7 cells. CONCLUSIONS: Lf CECT5716 is a growth-promoting strain upon undernutrition in Drosophila, with a maintained effect when added to an infant formula but without effect on lipid absorption in vitro.
- MeSH
- Caco-2 buňky MeSH
- časové faktory MeSH
- chronická nemoc MeSH
- Drosophila melanogaster MeSH
- enterocyty cytologie MeSH
- kokultivační techniky MeSH
- Lactobacillus plantarum * MeSH
- larva mikrobiologie MeSH
- lidé MeSH
- Limosilactobacillus fermentum * MeSH
- lipidy chemie MeSH
- mateřské mléko mikrobiologie MeSH
- micely MeSH
- mikrobiota MeSH
- modely u zvířat MeSH
- náhražky mateřského mléka MeSH
- novorozenec MeSH
- podvýživa dietoterapie patofyziologie MeSH
- probiotika * MeSH
- techniky in vitro MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- novorozenec MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Enteroviruses have been associated with a host of clinical presentations including acute flaccid paralysis (AFP). The site of primary replication for most enteroviruses is the gastrointestinal tract (GIT) and lactic acid bacteria (LAB) may confer protection in the GIT against them. This study therefore investigates the antiviral potential of some selected lactic acid bacteria against enterovirus isolates recovered from AFP cases. The antiviral activities of Lactobacillus plantarum, Lactobacillus amylovorus, and Enterococcus hirae in broth culture, their cell-free supernatant (CFS), and bacterial cell pellets were assayed against Echovirus 7 (E7), E13, and E19 in a pre- and post-treatment approach using cytopathic effect (CPE) and cell viability (MTT) assay. The tested Lactobacillus plantarum, Lactobacillus amylovorus, and Enterococcus hirae strains have good antiviral properties against E7 and E19 but not against E13. Lactobacillus amylovorus AA099 shows the highest activity against E19. The pre-treatment approach displays better antiviral activities compared to post-treatment approach. The LAB in broth suspension have better antiviral activities than their corresponding CFS and bacterial pellet. Lactic acid bacteria used in this study have the potential as antiviral agents.
- MeSH
- antivirové látky farmakologie MeSH
- druhová specificita MeSH
- Enterococcus hirae fyziologie MeSH
- enterovirové infekce prevence a kontrola virologie MeSH
- Enterovirus klasifikace účinky léků MeSH
- Lactobacillales fyziologie MeSH
- Lactobacillus acidophilus fyziologie MeSH
- Lactobacillus plantarum fyziologie MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- probiotika farmakologie MeSH
- viabilita buněk MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
