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1.
Sci Total Environ ; 802: 149792, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34464790

RESUMO

The eco-sustainability of industrial processes relies on the proper exploitation of by-products and wastes. Recently, brewers' spent grain (BSG), the main by-product of brewing, was successfully recycled through vermicomposting to produce an organic soil conditioner. However, the pre-processing step there applied (oven-drying) resulted in high costs and the suppression of microbial species beneficial for soil fertility. To overcome these limitations, a low-input pre-processing step was here applied to better exploit BSG microbiota and to make BSG suitable for vermicomposting. During 51 days of pre-treatment, the bacterial and fungal communities of BSG were monitored by denaturing gradient gel electrophoresis (DGGE). Chemical (carbon, nitrogen, ammonium, nitrate content, dissolved organic carbon) and biochemical (dehydrogenase activity) parameters were also evaluated. Mature vermicompost obtained from pre-processed BSG was characterized considering its legal requirements (e.g., absence of pathogens and mycotoxins, lack of phytotoxicity on seeds), microbiota composition, and chemical properties. Results obtained showed that throughout the pre-process, the BSG microbiota was enriched in bacterial and fungal species of significant biotechnological and agronomic potential, including lactic acid bacteria (Weissella, Pediococcus), plant growth-promoting bacteria (Bacillus, Pseudomonas, Pseudoxhantomonas), and biostimulant yeasts (Pichia fermentans, Trichoderma reesei, Beauveria bassiana). Pre-processing increased the suitability of BSG for earthworms' activity to produce high-quality mature vermicompost.


Assuntos
Lactobacillales , Oligoquetos , Animais , Grão Comestível , Hypocreales , Pichia
2.
Meat Sci ; 183: 108661, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34467880

RESUMO

The increasing concern of consumers about food quality and safety and their rejection of chemical additives has promoted the breakthrough of the biopreservation field and the development of studies on the use of beneficial bacteria and their metabolites as potential natural antimicrobials for shelf life extension and enhanced food safety. Control of foodborne pathogens in meat and meat products represents a serious challenge for the food industry which can be addressed through the intelligent use of bio-compounds or biopreservatives. This article aims to systematically review the available knowledge about biological strategies based on the use of lactic acid bacteria to control the proliferation of undesirable microorganisms in different meat products. The outcome of the literature search evidenced the potential of several strains of lactic acid bacteria and their purified or semi-purified antimicrobial metabolites as biopreservatives in meat products for achieving longer shelf life or inhibiting spoilage and pathogenic bacteria, especially when combined with other technologies to achieve a synergistic effect.


Assuntos
Conservação de Alimentos/métodos , Lactobacillales/fisiologia , Produtos da Carne/microbiologia , Animais , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bacteriocinas/farmacologia , Microbiologia de Alimentos , Lactobacillales/metabolismo , Produtos da Carne/análise
3.
Meat Sci ; 183: 108658, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34482216

RESUMO

The flavour profiles of beef jerky separately inoculated with different autochthonous lactic acid bacteria (LAB) strains (Lactobacillus sakei BL6, Pediococcus acidilactici BP2, and Lactobacillus fermentum BL11) and a non-inoculated control were analysed using electronic nose (E-nose) and gas chromatography-ion mobility spectrometry (GC-IMS). GC-IMS results revealed a total of 42 volatile compounds in beef jerky. Inoculation of the three LAB strains decreased the levels of lipid autoxidation-derived aldehydes (e.g., hexanal, heptanal, octanal, and nonanal). In addition, inoculation of P. acidilactici BP2 increased the levels of esters. Principal component analysis of the E-nose and GC-IMS results could effectively differentiate non-inoculated beef jerky and beef jerky separately inoculated with different LAB strains. Furthermore, there was a high correlation between the E-nose and GC-IMS results, providing a theoretical basis for the identification of different beef jerky formulations and selection of autochthonous starter cultures for beef jerky fermentation.


Assuntos
Lactobacillales/fisiologia , Produtos da Carne/análise , Compostos Orgânicos Voláteis/análise , Animais , Bovinos , Cromatografia Gasosa , Nariz Eletrônico , Espectrometria de Mobilidade Iônica , Produtos da Carne/microbiologia , Análise de Componente Principal
4.
Int J Food Microbiol ; 361: 109444, 2022 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-34749186

RESUMO

"Torta del Casar" is a Spanish soft-ripened cheese made with sheep's raw milk and subjected to a short ripening process, which favors the growth of pathogenic microorganisms including Listeria monocytogenes. The development of strategies to control pathogens and minimize health risks associated with the presence of L. monocytogenes in these products is of great interest. In this regard, the anti-Listeria activity of a whey protein hydrolysate (ProH) alone or combined with six lactic acid bacteria strains isolated from cheese was evaluated in this study as a biocontrol strategy using a "Torta del Casar" cheese-based medium. The most active combinations of lactic acid bacteria assayed induced a reduction higher than two logarithmic units in the growth of L. monocytogenes (serotype 4b) compared to their respective control when they were co-inoculated in "Torta del Casar" cheese-based medium at 7 °C for 7 days. In addition, the observed downregulation of some key virulence genes of L. monocytogenes suggests that the strain Lactiplantibacillus plantarum B2 alone and combined with the strain Lactiplantibacillus spp. B4 are good candidates to be used as biocontrol agents against L. monocytogenes growth in traditional soft cheeses based on raw milk during their storage at refrigeration temperatures.


Assuntos
Anti-Infecciosos , Queijo , Lactobacillales , Listeria monocytogenes , Animais , Queijo/análise , Microbiologia de Alimentos , Hidrolisados de Proteína , Ovinos , Virulência , Soro do Leite
5.
Bioresour Technol ; 343: 126076, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34601026

RESUMO

Numerous attempts have been made to upscale biohydrogen production via dark fermentation (DF); however, the Achilles' heel of DF, i.e., lactic acid bacteria (LAB) contamination and overgrowth, hinders such upscaling. Key microbes are needed to develop a lactate-driven DF system that can serve as a lactate fermentation platform. In this study, the utility of Megasphaera elsdenii and LAB co-culturing in lactate-driven DF was evaluated. When inoculated simultaneously with LAB or after LAB culture, M. elsdenii achieved a stable hydrogen yield of 0.95-1.49 H2-mol/mol-glucose, approximately half that obtained in pure M. elsdenii cultures. Hydrogen production was maintained even at an initial M. elsdenii-to-LAB cell ratio of one-millionth or less. Moreover, M. elsdenii produced hydrogen via lactate-driven DF from unusable sugars such as xylose or cellobiose. Thus, M. elsdenii could be a Game changer instrumental in unlocking the full potential of DF.


Assuntos
Lactobacillales , Megasphaera elsdenii , Animais , Fermentação , Hidrogênio/metabolismo , Ácido Láctico/metabolismo , Rúmen/metabolismo
6.
Shokuhin Eiseigaku Zasshi ; 62(5): 148-156, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34732640

RESUMO

Aflatoxins (AFs) are known to be oncogenic mycotoxins. This study investigated the mitigation effects of lactic acid bacteria (LAB) isolated from four types of vegetable, cucumber, Chinese cabbage, Japanese radish and eggplant, which are used to make Japanese traditional fermented pickles, on AFs. Using aflatoxin M1 (AFM1) binding assay for screening, four representative strains were selected (one from each vegetable) from total 94 LAB strains, based on the highest binding ratio. The ranges of the binding ratio of these representative strains to aflatoxin B1 (AFB1), aflatoxin B2, aflatoxin G1, aflatoxin G2 and AFM1 were 57.5%-87.9% for the LAB strain derived from cucumber, 18.9%-43.9% for the LAB strain derived from Chinese cabbage, 26.4%-41.7% for the LAB strain derived from Japanese radish, and 15.0%-42.6% for the LAB strain derived from eggplant. The strains isolated from cucumber, Chinese cabbage, Japanese radish and eggplant were identified as Lactococcus lactis subsp. lactis, Weissella cibaria, Leuconostoc mesenteroides and Leu. mesenteroides, respectively. An in vitro binding assay of the four strains under acidic conditions showed that the number of living bacteria decreased, while the binding ratio increased in some strains, suggesting that the LAB maintained their capacity to bind aflatoxins even in an environment that imitated the stomach. An in vivo experiment using L. lactis subsp. lactis derived from cucumber revealed that the bacteria significantly inhibited the absorption of AFB1 into blood. These results showed that the LAB used for Japanese vegetable pickles was an effective binding agent of AFs and suggested that they might play a role in mitigating AF absorption.


Assuntos
Aflatoxinas , Lactobacillales , Weissella , Verduras
7.
J Nutr Sci Vitaminol (Tokyo) ; 67(5): 351-357, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34719621

RESUMO

Atrogin-1, which is an important regulator of ubiquitin-mediated protein degradation in skeletal muscle, is a major marker of muscle loss and disuse muscle atrophy. To investigate which components of lactic acid bacteria (LAB) suppress dexamethasone (DEX)-induced atrogin-1 expression, mouse skeletal muscle C2C12 myotubes were treated with DEX in the presence or absence of components of LAB. Heat-killed cells and lipoteichoic acid (LTA) derived from five LAB strains significantly suppressed DEX-induced atrogin-1 expression. The glycerophosphate (GroP) fraction prepared from chemically-degraded LTA and sn-glycerol-1-phosphate suppressed DEX-induced atrogin-1 expression, whereas the glycolipid anchor fraction of LTA did not. Heat-killed cells obtained by culturing under low-Mn2+ conditions, which generated fewer poly-GroP polymers in LTA, displayed significantly lower inhibitory activity compared to heat-killed cells grown under normal conditions. These results suggested that LTA of LAB contributed to suppressing atrogin-1 expression and that the GroP moiety of LTA was responsible for its inhibitory activity.


Assuntos
Lactobacillales , Atrofia Muscular , Animais , Dexametasona/farmacologia , Glicerofosfatos , Lipopolissacarídeos , Camundongos , Fibras Musculares Esqueléticas , Proteínas Musculares , Músculo Esquelético/patologia , Atrofia Muscular/patologia , Proteínas Ligases SKP Culina F-Box , Ácidos Teicoicos , Ubiquitina-Proteína Ligases
8.
Molecules ; 26(19)2021 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-34641607

RESUMO

The application of bacterial cultures in food fermentation is a novel strategy to increase the "natural" levels of bioactive compounds. The unique ability of lactic acid bacteria (LAB) to produce folate, B vitamins, and conjugated linolenic acid cis9trans11 C18:2 (CLA) during cold storage up to 21 days was studied. Although some species of LAB can produce folates and other important nutrients, little is known about the production ability of yogurt starter cultures. Pasteurized milk samples were inoculated with four different combinations of commercially available yogurt vaccines, including starter cultures of Bifidobacterium bifidum. Both the type of vaccine and the time of storage at 8 °C had a significant effect on the folate and CLA contents in the tested fermented milks. The highest folate content (105.4 µg/kg) was found in fresh fermented milk inoculated with Lactobacillus delbrueckii, Streptococcus thermophilus, and Bifidobacterium bifidum. Only the mix of Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus thermophilus, and Bifidobacterium bifidum showed potential (59% increase) to synthesize folate during seven days of storage. A significant increase in the content of CLA, when compared to fresh fermented milk, was observed during cold storage for up to 21 days in products enriched with Bifidobacterium bifidum.


Assuntos
Produtos Fermentados do Leite/microbiologia , Ácido Fólico/metabolismo , Lactobacillales/metabolismo , Ácidos Linoleicos Conjugados/metabolismo , Leite/metabolismo , Leite/microbiologia , Complexo Vitamínico B/metabolismo , Animais , Bifidobacterium bifidum/metabolismo , Biofortificação/métodos , Fermentação , Microbiologia de Alimentos , Lactobacillus delbrueckii/metabolismo , Probióticos , Streptococcus thermophilus/metabolismo , Fatores de Tempo
9.
Molecules ; 26(19)2021 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-34641608

RESUMO

The effect of spontaneous fermentation by lactic acid bacteria on the extraction yield of bioactive compounds and antioxidant activity from rosemary leaf extracts was investigated using high-performance thin-layer chromatography (HPTLC). Brining and spontaneous fermentation with lactic acid bacteria more than doubled extraction of polyphenolics and antioxidants from the rosemary leaves. The results show that lactic acid fermentation enhances antioxidant activity in extracts by increasing the total phenolic content but does not increase extraction of phytosterols. Increased extraction of phenolic oxidants during fermentation assisted extraction, results from the in situ generated natural eutectic solvent from the plant sample. ATR-FTIR spectra from the bioactive bands suggests that this increased antioxidant activity is associated with increased extraction of rosmarinic acid, depolymerised lignin, abietane diterpenoids and 15-hydroxy-7-oxodehydroabietic acid.


Assuntos
Antioxidantes/química , Antioxidantes/metabolismo , Lactobacillales/metabolismo , Extratos Vegetais/química , Extratos Vegetais/metabolismo , Rosmarinus/química , Rosmarinus/metabolismo , Abietanos/química , Abietanos/metabolismo , Cromatografia em Camada Delgada , Cinamatos/química , Cinamatos/metabolismo , Depsídeos/química , Depsídeos/metabolismo , Fermentação , Humanos , Lignina/química , Lignina/metabolismo , Fenóis/química , Fenóis/metabolismo , Folhas de Planta/química , Folhas de Planta/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier
10.
J Biosci Bioeng ; 132(6): 575-584, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34600807

RESUMO

Emerging concern about the emergence of antimicrobial resistance has limited the use of antibiotics in calves. Hence, there is a need to find suitable alternatives to antibiotics to manage gastrointestinal infections in neonatal calves. The objective of the present study was to develop a probiotic of calf-origin for its potential application in calf nutrition. Accordingly, 69 lactic acid bacteria (LAB) strains were isolated from faeces of newborn calves, out of which 10 strains were short-listed for further in vitro testing based on the aggregation time and cell surface hydrophobicity. The results of acid-, bile- and phenol-tolerance tests indicated that out of the ten strains, the isolate CPN60 had better resistance to these adverse conditions likely to be encountered in the gastrointestinal tract. The isolate also showed an optimal ability to produce biofilm. Further assessments reiterated its superiority in terms of co-aggregation and antagonistic activity against pathogenic strains of Escherichia coli. Subsequently, the isolate was identified through 16S rRNA sequencing and sequence homology and designated as Ligilactobacillus salivarius CPN60. The candidate probiotic was evaluated in vivo using 48 male (5 weeks old) Wistar rats, divided into two equal groups viz. control (CON) and probiotic (PRO). During the 4-weeks feeding trial, the PRO group rats were gavaged with one mL culture of L. salivarius CPN60 equivalent to 108 CFU/rat. The in vivo trial results indicated better nutrient utilization efficiency and growth performance (p < 0.001) of the PRO group of rats. The probiotic supplementation improved the faecal concentration of lactate (p < 0.001) and individual as well as total short-chain fatty acids (p < 0.001) production. The cell-mediated immune response, assessed as a delayed-type hypersensitivity reaction to phytohaemagglutinin-P, was improved (p < 0.001) in PRO compared to the CON rats. It is concluded that the calf-origin probiotic L. salivarius CPN60, in addition to possessing all the in vitro functional attributes of a candidate probiotic, also has desirable potential for its future use in young calves to promote gut health and immunity.


Assuntos
Lactobacillales , Probióticos , Animais , Bovinos , Fezes , Lactobacillales/genética , Masculino , RNA Ribossômico 16S/genética , Ratos , Ratos Wistar
11.
Food Res Int ; 149: 110674, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34600676

RESUMO

The aim of this paper was to evaluate the influence of different indigenous lactic acid bacteria isolates - as a single culture or bacterial consortium - on the functional and physicochemical properties of fermented curly kale juice. All tested variants exhibited good growth parameters, manifested by efficient pH lowering, increases in acidity, and fructose and glucose metabolism, as well as a significant inhibition of pathogens. A slight increase in total phenolic content was observed, while antioxidant activity remained unchanged. L. sakei and MIX A were associated with an increase in riboflavin and pyridoxine content, while L. plantarum only contributed to an increase in vitamin B6 content. Bioconversion of individual phenolic compounds, carotenoids, and glucosinolates strongly depended on the strain-specific metabolism. In the process, the levels of ferulic acid and other hydroxycinnamic acids were maintained, while the content of 9-cis lutein increased. Considering presented results and our previous research regarding probiotic features of LAB strains, among tested starter cultures - L. plantarum seemed to possess the best characteristics as a potential starter culture for controlled fermentation of curly kale juice.


Assuntos
Brassica , Lactobacillales , Probióticos , Fermentação , Microbiologia de Alimentos
12.
Appl Microbiol Biotechnol ; 105(21-22): 8427-8440, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34625821

RESUMO

Aging is associated with gut microbiota alterations, characterized by changes in intestinal microbial diversity and composition. However, no study has yet focused on investigating age-related changes in the low-abundant but potentially beneficial subpopulations of gut lactic acid bacteria (LAB) and Bifidobacterium. Our study found that the subjects' age correlated negatively with the alpha diversity of the gut bifidobacterial microbiota, and such correlation was not observed in the gut LAB subpopulation. Principal coordinate analysis (PCoA) and analysis of distribution of operational taxonomic units (OTUs) revealed that the structure and composition of the gut bifidobacterial subpopulation of the longevous elderly group were rather different from that of the other three age groups. The same analyses were applied to identify age-dependent characteristics of the gut LAB subpopulation, and the results revealed that the gut LAB subpopulation of young adults was significantly different from that of all three elderly groups. Our study identified several potentially beneficial bacteria (e.g., Bifidobacterium breve and Bifidobacterium longum) that were enriched in the longevous elderly group (P < 0.05), and the relative abundance of Bifidobacterium adolescentis decreased significantly with the increase in age (P < 0.05). Although both bifidobacteria and LAB are generally considered as health-promoting taxa, their age-dependent distribution varied from each other, suggesting their different life stage changes and potentially different functional roles. This study provided novel species-level gut bifidobacterial and LAB microbiota profiles of a large cohort of subjects and identified several age-or longevity-associated features and biomarkers. KEY POINTS: • The alpha diversity of the gut bifidobacterial microbiota decreased with age, while LAB did not change. • The structure and composition of the gut bifidobacterial subpopulation of the longevous elderly group were rather different from that of the other three age groups. • Several potentially beneficial bacteria (e.g., Bifidobacterium breve and Bifidobacterium longum) that were enriched in the longevous elderly group.


Assuntos
Bifidobacterium longum , Microbioma Gastrointestinal , Lactobacillales , Idoso , Envelhecimento , Bifidobacterium , Fezes , Humanos
13.
Appl Microbiol Biotechnol ; 105(19): 7367-7378, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34536099

RESUMO

Fluorescent proteins are widely used for cell and protein tracking. Most of these proteins show a high signal and need the presence of oxygen to emit fluorescence. Among them, the fluorescent protein mCherry stands up because of its bright signal and fast maturation. Furthermore, the anaerobic cyan-green fluorescent protein Evoglow-Pp1 allows fluorescent detection under anaerobic conditions. In this work, we modified the pNZ:TuR.aFP plasmid, which harbors the gene encoding Evoglow-Pp1 and the promoter of elongation factor Tu from Limosilactobacillus reuteri CECT925, to obtain a plasmid containing the mrfp gene encoding the monomeric mCherry (pNZ:TuR.mCherry). Moreover, both genes were cloned together (pNZ:TuR.aFP.mCherry) developing a chimeric protein; and with a stop codon between them (pNZ:TuR.aFP.STOP.mCherry) resulting in the expression of both Evoglow-Pp1 and mCherry proteins separately under the influence of the same promoter. Lactococcus lactis, Lacticaseibacillus casei, Lactiplantibacillus plantarum, Limosilactobacillus fermentum, Lacticaseibacillus rhamnosus, and L. reuteri strains were transformed with the previously mentioned plasmids, showing an excellent red (pNZ:TuR.mCherry), green (pNZ:TuR.aFP), and red combined with green (pNZ:TuR.aFP.mCherry and pNZ:TuR.aFP.STOP.mCherry) fluorescence signal. Both fluorescence emissions were stable in strains transformed with pNZ:TuR.aFP.STOP.mCherry, while differences in the red or green fluorescence emission were observed in some of the strains harboring pNZ:TuR.aFP.mCherry. Moreover, these plasmids allowed strains differentiation in a complex environment, such as fecal microbiota. Hence, we present the plasmid pNZ:TuR.aFP.STOP.mCherry as a useful tool for the labeling of lactobacilli strains, which would be functional under anoxic conditions, thanks to Evoglow-Pp1, while having the high brightness and good photostability of mCherry. KEY POINTS: • LAB transformed with pNZ:TuR.mCherry expressed the red fluorescent protein mCherry. • LAB transformed with pNZ:TuR.aFP.mCherry developed a fusion of both proteins Evoglow-Pp1 and mCherry. • LAB with pNZ:TuR.aFP.STOP.mCherry expressed both fluorescent proteins separately.


Assuntos
Lactobacillales , Proteínas Luminescentes , Lactobacillales/isolamento & purificação
14.
Food Res Int ; 148: 110605, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34507749

RESUMO

Effects of mixed cultures composed of any two of four autochthonous lactic acid bacteria on fermentation of Chinese northeast sauerkraut were investigated in this study. Results indicated that different mixed cultures inoculation generated diversified physicochemical, microbiological and flavor quality of sauerkraut. Compared to spontaneous fermentation, mix-culture fermentation showed significant higher population of lactic acid bacteria and lower amounts of undesirable microorganisms. Free amino acids increased by 2- to 5-fold from initial level in spontaneous and mix-culture fermentation, with the lowest production by spontaneous fermentation. Moreover, mix-culture fermentation promoted the flavor formation based on the analysis of HS-SPME/GC-MS, E-nose, E-tongue and sensory evaluation, especially for the mixed culture of Leu. mesenteroides and L. plantarum. These results highlighted that using a mixed culture made up with Leu. mesenteroides and L. plantarum could be a potential way to improve the quality of sauerkraut, which could provide an alternative way to meet consumers' requirement.


Assuntos
Brassica , Lactobacillales , China , Fermentação , Microbiologia de Alimentos , Metaboloma
15.
Food Res Int ; 148: 110622, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34507766

RESUMO

Fermented vegetable flavors are closely associated with microbial metabolism. Here, shifts in flavor metabolites and their correlations to the structure and function of fermentative microbial communities were explored during the spontaneous fermentation process of potherb mustard (Brassica juncea var. multiceps), a traditionally fermented vegetable from China. Halophilic bacteria (HAB, i.e., Halomonas, Salinivibrio, and Vibrio) and lactic acid bacteria (LAB, i.e., Lactobacillus-related genera and Weissella) became highly abundant after potherb mustard fermentation. Further, HAB and LAB abundances exhibited significant, positive correlations with metabolites important in fermented potherb mustard flavoring (e.g., organic acids, amino acids, alcohols, aldehydes, and nitriles). Metagenomic analysis indicated that Halomonas, Salinivibrio, Weissella, and Lactobacillus-related genera were likely actively engaged in pyruvate metabolism (ko00620) and citrate cycle (TCA cycle, ko00020), leading to higher lactic and acetic acid concentrations, along with lower pH, which would affect levels of volatile isothiocyanates and nitriles that contribute to flavoring of fermented potherb mustard. Further, HAB and LAB were the primary populations inferred to be responsible for amino acid and fatty acid metabolism in addition to the biosynthesis of numerous volatile flavor compounds. This study highlights the predominance and importance of LAB and HAB during spontaneous fermentation of potherb mustard and provides new insights into their roles in this process.


Assuntos
Lactobacillales , Microbiota , Fermentação , Lactobacillales/genética , Metagenômica , Mostardeira/genética
16.
Int J Food Microbiol ; 357: 109382, 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34509932

RESUMO

Dairy farm management practices can modify milk microbiota and therefore modulate non-starter lactic acid bacteria (NSLAB) found in cheese. These NSLAB can cause organoleptic defects. This study aimed to investigate the impact of two potential NSLAB in Cheddar cheesemaking: Lactiplantibacillus plantarum RKG 2-212 a strain isolated both in corn silage and raw milk, and Lactobacillus delbrueckii RKG R10, a strain isolated after pasteurisation of milk from a farm using grass and legume silage, and corn silage. The whole genome of these two lactobacilli was first sequenced. Then, the thermoresistance was evaluated after treatment at 60 °C for 5 min and compared to reference strains. Both lactobacilli were highly thermoresistant compared to other three lactic acid bacteria which are Lactococcus lactis subsp. cremoris ATCC 19257 and SK11, and L. plantarum ATCC 14917 (P < 0.0001). They lost less than 1 log cfu/mL (Δlog) and their genome contained a great number of copy number of genes coding for heat shock protein. During a Pearce test activity simulating Cheddar cheesemaking, the two lactobacilli did not show interaction with the starter Lcc. lactis subsp. cremoris SK11, and their population remained stable. During a ripening simulation, L. delbrueckii RKG R10 had a slight loss in viability in cheese slurry samples incubated at 30 °C for 12 d. However, L. plantarum RKG 2-212 had considerable growth, from 6.51 to 8.3 log cfu/g. This growth was associated with the acidification of the slurries (P < 0.0001). The presence of the lactobacilli modified the profile of volatile compounds evaluated by gas chromatography-mass spectrometry, accounting for 10.7% of the variation. The strain L. plantarum RKG 2-212 produced volatile compounds in greater quantity that could be associated with organoleptic defects such as acetic acid and 2-methylbutyraldehyde. Therefore, silage can be a vector of thermoresistant lactic acid bacteria for milk which can lead to flavor defects in cheese.


Assuntos
Queijo , Lactobacillales , Lactococcus lactis , Animais , Lactobacillales/genética , Lactococcus , Lactococcus lactis/genética , Leite
17.
Toxicon ; 202: 115-122, 2021 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-34562499

RESUMO

Fusarium graminearum invasion and Zearalenone (ZEN)-mycotoxin contamination are considered the most global threat to food and feed. This study investigates the effect Lactobacillus plantarum MON03 viable cells (LPVC) and LP free cells supernatant (LPFCS) against Fusarium graminearum growth and ZEN production in vitro and evaluates if treatment with LP viable cells can counteract the negative effect of ZEN on inflammation and oxidative stress in mesenteric lymph nodes and serum biochemical parameters in mice. For the in vitro study, 7 days of LPVC, LPFCS and F. graminearum co-incubation at different concentrations was done in order to determine the antifungal activity and ZEN- production inhibition. Regarding the in vivo study, Balb/c mice were treated as following: Control, ZEN group, LP group and ZEN + LP group for 30 days. In vitro, LPVC showed an excellent antifungal activity after 7 days of co-incubation (103 CFU/ml). LPVC was succeeded also to inhibit ZEN production by the fungi. In vivo, ZEN has shown an important oxidative damage. As a result of the exposure to ZEN, an increase cytokines, as effectors of an inflammatory response, were observed in the mesenteric lymph nodes (MLN) of intoxicated mice. In parallel, a serum biochemical change was also observed. LPVC induced a reduction of ZEN-induced oxidative stress and counteracts also the biochemical parameters damage and the inflammatory markers increased by ZEN. LPVC can be valorized as an anti-cating agent in the vitro and in the gastro-intestinal tract to decrease ZEN-toxic effects.


Assuntos
Fusarium , Lactobacillales , Zearalenona , Animais , Suplementos Nutricionais , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Camundongos , Estresse Oxidativo , Zearalenona/análise , Zearalenona/toxicidade
18.
Molecules ; 26(18)2021 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-34577129

RESUMO

This study developed a nutritionally valuable product with bioactive activity that improves the quality of bread. Djulis (Chenopodium formosanum), a native plant of Taiwan, was fermented using 23 different lactic acid bacteria strains. Lactobacillus casei BCRC10697 was identified as the ideal strain for fermentation, as it lowered the pH value of samples to 4.6 and demonstrated proteolysis ability 1.88 times higher than controls after 24 h of fermentation. Response surface methodology was adopted to optimize the djulis fermentation conditions for trolox equivalent antioxidant capacity (TEAC). The optimal conditions were a temperature of 33.5 °C, fructose content of 7.7%, and dough yield of 332.8, which yielded a TEAC at 6.82 mmol/kg. A 63% increase in TEAC and 20% increase in DPPH were observed when compared with unfermented djulis. Subsequently, the fermented djulis was used in different proportions as a substitute for wheat flour to make bread. The total phenolic and flavonoid compounds were 4.23 mg GAE/g and 3.46 mg QE/g, marking respective increases of 18% and 40% when the djulis was added. Texture analysis revealed that adding djulis increased the hardness and chewiness of sourdough breads. It also extended their shelf life by approximately 2 days. Thus, adding djulis to sourdough can enhance the functionality of breads and may provide a potential basis for developing djulis-based functional food.


Assuntos
Pão , Fermentação , Farinha , Antioxidantes , Lactobacillales
19.
Int J Mol Sci ; 22(15)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34360567

RESUMO

Resistance to antimicrobials is a growing problem of worldwide concern. Plasmids are thought to be major drivers of antibiotic resistance spread. The present work reports a simple way to recover replicative plasmids conferring antibiotic resistance from the bacteria in cheese. Purified plasmid DNA from colonies grown in the presence of tetracycline and erythromycin was introduced into plasmid-free strains of Lactococcus lactis, Lactiplantibacillus plantarum and Lacticaseibacillus casei. Following antibiotic selection, the plasmids from resistant transformants were isolated, analyzed by restriction enzyme digestion, and sequenced. Seven patterns were obtained for the tetracycline-resistant colonies, five from L. lactis, and one each from the lactobacilli strains, as well as a single digestion profile for the erythromycin-resistant transformants obtained in L. lactis. Sequence analysis respectively identified tet(S) and ermB in the tetracycline- and erythromycin-resistance plasmids from L. lactis. No dedicated resistance genes were detected in plasmids conferring tetracycline resistance to L. casei and L. plantarum. The present results highlight the usefulness of the proposed methodology for isolating functional plasmids that confer antibiotic resistance to LAB species, widen our knowledge of antibiotic resistance in the bacteria that inhabit cheese, and emphasize the leading role of plasmids in the spread of resistance genes via the food chain.


Assuntos
Antibacterianos/farmacologia , Queijo/microbiologia , Resistência Microbiana a Medicamentos , Eritromicina/farmacologia , Lactobacillales/crescimento & desenvolvimento , Plasmídeos/genética , Animais , Lactobacillales/efeitos dos fármacos , Lactobacillales/isolamento & purificação
20.
Food Res Int ; 147: 110460, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34399460

RESUMO

A novel concept of stabilizing multiple-phase food structure such as emulsion using solely the constitutional bacteria enables an all-natural food grade formulation and thus a clean label declaration. In this paper, we propose an efficient approach to hydrophobically modifying the surface of lactic acid bacteria Lactobacillus rhamnosus (LGG) using lauroyl ahloride (LC) in non-aqueous media. Compared to the unmodified bacteria, cell hydrophobicity was dramatically altered upon modification, according to the higher percentages of microbial adhesion to hexadecane (MATH) and water contact angles (WCA) of LC-modified bacteria. No evident changes were found in bacterial surface charge before and after LC modification. By using one-step homogenization, all the modified bacteria were able to generate stabile water-in-oil-in-water (W/O/W) double emulsions where bacteria were observed on oil-water interfaces of the primary and secondary droplets. Modification using high LC concentrations (10 and 20 w/w%) led to rapid autoaggregation of bacteria in aqueous solution. A long-term lethal effect of modification primarily came from lyophilization and no apparent impact was detected on the instantaneous culturability of modified bacteria.


Assuntos
Lactobacillales , Emulsões , Interações Hidrofóbicas e Hidrofílicas
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