RESUMEN
The aim of this study was to obtain drinking yogurts enriched with ACTICOA cocoa powder (ACTICOA), its extract (EACTICOA) and pure phenolics, as well as their inclusion complexes with cyclodextrins and alginate-chitosan (A-Ch) capsules, and to evaluate the effects of these additives on the viability of lactic acid bacteria (LAB) and antioxidant properties of fresh yogurts and yogurts stored for 14 days at 4 °C. The application of cocoa phenolic compounds in free form and in the form of EACTICOA to yogurts resulted in the greatest increase in the concentration of phenolic compounds and a significant improvement in the antioxidant properties of the fortified products. The highest TPC was found in yogurts enriched with free quercetin (107.98 mg CE/g). Yogurt fortified with free gallic acid showed the highest ability to neutralize free radicals (EC50 = 2.74 mg/mg DPPH, EC50 = 5.40 mg/mg ABTS) and reduce ferric ions (183.48 µM Trolox/g). The enrichment of yogurts with the tested phenolic compounds preparations, especially in the form of encapsulates, did not affect the viability of LAB during storage.
Asunto(s)
Antioxidantes , Cacao , Lactobacillales , Fenoles , Yogur , Yogur/microbiología , Yogur/análisis , Antioxidantes/farmacología , Antioxidantes/química , Fenoles/análisis , Fenoles/farmacología , Fenoles/química , Cacao/química , Lactobacillales/crecimiento & desarrollo , Alimentos Fortificados/análisis , Quitosano/química , Quitosano/farmacología , Alginatos/química , Alginatos/farmacología , Extractos Vegetales/farmacología , Extractos Vegetales/química , CápsulasRESUMEN
The aim of this study was to develop a novel and healthier fermented meat product by replacing pork fat with avocado pulp (AVP) during salami production. Experimental salamis were produced under laboratory conditions by substituting pork fat with AVP partially (10-AVP) and totally (20-AVP), while control salamis (CTR) remained AVP-free. The microbial composition of control and experimental salamis was assessed using a combined culture-dependent and -independent approach. Over a 20-days ripening period, lactic acid bacteria, coagulase-negative staphylococci, and yeasts dominated the microbial community, with approximate levels of 9.0, 7.0 and 6.0 log CFU/g, respectively. Illumina technology identified 26 taxonomic groups, with leuconostocs being the predominant group across all trials [constituting 31.26-59.12 % of relative abundance (RA)]. Gas Chromatography-Mass Spectrometry (GC-MS) analysis revealed changes in fatty acid composition and volatile organic compounds due to the substitution of pork fat with AVP. Specifically, monounsaturated fatty acids and terpene compounds increased, while saturated fatty acids and lipid oxidation products decreased. Although AVP influenced the sensory characteristics of the salamis, the highest overall satisfaction ratings were observed for the 10-AVP salamis. Consequently, substituting pork fat with AVP emerges as a viable strategy for producing healthier salamis and diversifying the meat product portfolio.
Asunto(s)
Fermentación , Productos de la Carne , Persea , Persea/microbiología , Persea/química , Animales , Porcinos , Productos de la Carne/microbiología , Productos de la Carne/análisis , Ácidos Grasos/análisis , Ácidos Grasos/metabolismo , Humanos , Bacterias/clasificación , Bacterias/aislamiento & purificación , Bacterias/metabolismo , Bacterias/genética , Compuestos Orgánicos Volátiles/análisis , Compuestos Orgánicos Volátiles/metabolismo , Frutas/microbiología , Frutas/química , Microbiología de Alimentos , Gusto , Lactobacillales/metabolismo , Lactobacillales/clasificación , Lactobacillales/crecimiento & desarrolloRESUMEN
Fermentation contributes to the taste and odor of plant cheeses. The selection of functional cultures for the fermentation of plant cheeses, however, is in its infancy. This study aimed to select lactic acid bacteria for ripening of soy and lupin cheese analogues. Bacillus velezensis and B. amyloliquefaciens were used for germination of seeds to produce proteolytic enzymes; Lactococcus lactis and Lactiplantibacillus plantarum served as primary acidifying cultures. Levilactobacillus hammesii, Furfurilactobacillus milii, or Lentilactobacillus buchneri were assessed as adjunct cultures for the ripening of plant cheese. Growth of bacilli was inhibited at low pH. Both Lc. lactis and Lp. plantarum were inactived during plant cheese ripening. Cell counts of Lv. hammesii remained stable over 45 d of ripening while Ff. milii and Lt. buchneri grew slowly. Sequencing of full length 16S rRNA genes confirmed that the inocula the plant cheeses accounted for more than 98% of the bacterial communities. HPLC analysis revealed that Lt. buchneri metabolized lactate to acetate and 1,2-propanediol during ripening. Bacilli enhanced proteolysis as measured by quantification of free amino nitrogen, and the release of glutamate. LC-MS/MS analysis quantified kokumi-active dipeptides. The concentrations of γ-Glu-Leu, γ-Glu-Ile, and γ-Glu-Ala, γ-Glu-Cys in unripened cheeses were increased by seed germination but γ-Glu-Phe was degraded. Lt. buchneri but not Lv. hammesii or Ff. milii accumulated γ-Glu-Val, γ-Glu-Ile or γ-Glu-Leu during ripening, indicating strain-specific differences. In conclusion, a consortium of bacilli, acidification cultures and adjunct cultures accumulates taste- and kokumi-active compounds during ripening of plant cheeses.
Asunto(s)
Queso , Fermentación , Microbiología de Alimentos , Queso/microbiología , Queso/análisis , Lupinus/microbiología , Lupinus/crecimiento & desarrollo , Glycine max/microbiología , Glycine max/crecimiento & desarrollo , Gusto , Bacillus/metabolismo , Bacillus/genética , Bacillus/crecimiento & desarrollo , Concentración de Iones de Hidrógeno , Lactobacillales/metabolismo , Lactobacillales/genética , Lactobacillales/crecimiento & desarrollo , Lactococcus lactis/metabolismo , Lactococcus lactis/crecimiento & desarrollo , Lactococcus lactis/genética , ARN Ribosómico 16S/genéticaRESUMEN
AIMS: To develop antifungal lactic acid bacteria (LAB) and investigate their antifungal mechanisms against Aspergillus flavus in aflatoxin (AF) production. METHODS AND RESULTS: We isolated 179 LABs from cereal-based fermentation starters and investigated their antifungal mechanism against A. flavus through liquid chromatography-mass spectrometry and co-culture analysis techniques. Of the 179 isolates, antifungal activity was identified in Pediococcus pentosaceus, Lactobacillus crustorum, and Weissella paramesenteroides. These LABs reduced AF concentration by (i) inhibiting mycelial growth, (ii) binding AF to the cell wall, and (iii) producing antifungal compounds. Species-specific activities were also observed, with P. pentosaceus inhibiting AF production and W. paramesenteroides showing AF B1 binding activity. In addition, crucial extracellular metabolites for selecting antifungal LAB were involved in the 2',3'-cAMP-adenosine and nucleoside pathways. CONCLUSIONS: This study demonstrates that P. pentosaceus, L. crustorum, and W. paramesenteroides are key LAB strains with distinct antifungal mechanisms against A. flavus, suggesting their potential as biological agents to reduce AF in food materials.
Asunto(s)
Antifúngicos , Aspergillus flavus , Técnicas de Cocultivo , Lactobacillales , Metabolómica , Aspergillus flavus/metabolismo , Aspergillus flavus/crecimiento & desarrollo , Aspergillus flavus/efectos de los fármacos , Antifúngicos/farmacología , Antifúngicos/metabolismo , Lactobacillales/metabolismo , Lactobacillales/crecimiento & desarrollo , Fermentación , Aflatoxinas/biosíntesis , Grano Comestible/microbiología , Pediococcus pentosaceus/metabolismo , Antibiosis , Microbiología de AlimentosRESUMEN
The exopolysaccharide production from blueberry juice fermented were investigated. The highest exopolysaccharide yield of 2.2 ± 0.1 g/L (increase by 32.5 %) was reached under the conditions of temperature 26.5 °C, pH 5.5, inoculated quantity 5.4 %, and glucose addition 9.1 % using the artificial neural network and genetic algorithm. Under the optimal conditions, the viable cell counts and total acids were increased by 2.0 log CFU/mL and 1.6 times, respectively, while the content of phenolics and anthocyanin was decreased by 9.26 % and 7.86 %, respectively. The changes of these components affected the exopolysaccharide biosynthesis. The absorption bands of -OH and -CH associated with the main functional groups of exopolysaccharide were detected by Visible near-infrared spectroscopy. The prediction model based on spectrum results was constructed. Competitive adaptive reweighted sampling and the random forest were used to enhance the model's prediction performance with the value of RC = 0.936 and RP = 0.835, indicating a good predictability of exopolysaccharides content during fermentation.
Asunto(s)
Arándanos Azules (Planta) , Fermentación , Jugos de Frutas y Vegetales , Lactobacillales , Espectroscopía Infrarroja Corta , Arándanos Azules (Planta)/química , Arándanos Azules (Planta)/metabolismo , Arándanos Azules (Planta)/microbiología , Jugos de Frutas y Vegetales/análisis , Jugos de Frutas y Vegetales/microbiología , Lactobacillales/metabolismo , Lactobacillales/crecimiento & desarrollo , Polisacáridos Bacterianos/metabolismo , Polisacáridos Bacterianos/químicaRESUMEN
Single starter can hardly elevate the gel property of fermented freshwater fish sausage. In this work, in order to improve the physical properties of tilapia sausage, two newly isolated strains of lactic acid bacteria (LAB), Latilactobacillus sakei and Pediococcus acidilactici were used for cooperative fermentation of tilapia sausage, followed by the revelation of their formation mechanisms during cooperative fermentation and their improvement mechanisms after comparison with natural fermentation. Both strains, especially L. sakei possessed good growth, acidification ability, and salt tolerance. The gel strength, hardness, springiness, chewiness, whiteness, acidification, and total plate count significantly elevated during cooperative fermentation with starters. Pediococcus, Acinetobacter, and Macrococcus were abundant before fermentation, while Latilactobacillus quickly occupied the dominant position after fermentation for 18-45 h with the relative abundance over 51.5 %. The influence of each genus on the physical properties was calculated through the time-dimension and group-dimension correlation networks. The results suggested that the increase of Latilactobacillus due to the good growth and metabolism of L. sakei contributed the most to the formation and improvement of gel strength, texture properties, color, acidification, and food safety of tilapia sausage after cooperative fermentation. This study provides a novel analysis method to quantitatively evaluate the microbial contribution on the changes of various properties. The cooperative fermentation of LAB can be used for tilapia sausage fermentation to improve its physical properties.
Asunto(s)
Fermentación , Productos Pesqueros , Microbiología de Alimentos , Tilapia , Animales , Tilapia/microbiología , Productos Pesqueros/microbiología , Concentración de Iones de Hidrógeno , Latilactobacillus sakei/metabolismo , Lactobacillales/metabolismo , Lactobacillales/aislamiento & purificación , Lactobacillales/crecimiento & desarrollo , Pediococcus acidilactici/metabolismo , Alimentos Fermentados/microbiología , Productos de la Carne/microbiologíaRESUMEN
This study aimed to investigate the interaction between L.casei and L.bulgaricus with Polygonatum sibiricum saponins (PSS) and to explore the co-microencapsulation to reduce their loss rate during storage and consumption. 1% PSS was added to the culture broth, and it was found that the growth and metabolism of the strains were accelerated, especially in the compound probiotic group, indicating that PSS has potential for prebiotics. LC-MS observed significant differences in the composition and content of saponins in PSS. The metabolomics results suggest that the addition of PSS resulted in significant changes in the metabolites of probiotics. In addition, it was found that the combination of probiotics and PSS may have stronger hypoglycemic ability (É-glucosidase, HepG2). Finally, a co-microencapsulated delivery system was constructed using zein and isomaltooligosaccharide. This system can achieve more excellent resistance of probiotics and PSS in gastrointestinal fluids, effectively transporting both to the small intestine.
Asunto(s)
Composición de Medicamentos , Polygonatum , Probióticos , Saponinas , Saponinas/química , Saponinas/metabolismo , Saponinas/farmacología , Humanos , Probióticos/metabolismo , Probióticos/química , Polygonatum/química , Polygonatum/metabolismo , Prebióticos/análisis , Lactobacillus/metabolismo , Lactobacillus/química , Lactobacillus/crecimiento & desarrollo , Lactobacillales/metabolismo , Lactobacillales/crecimiento & desarrollo , Lactobacillales/químicaRESUMEN
Since the late nineteenth century, the agricultural sector has experienced a tremendous increase in chemical use in response to the growing population. Consequently, the intensive and indiscriminate use of these substances caused serious damage on several levels, including threatening human health, disrupting soil microbiota, affecting wildlife ecosystems, and causing groundwater pollution. As a solution, the application of microbial-based products presents an interesting and ecological restoration tool. The use of Plant Growth-Promoting Microbes (PGPM) affected positive production, by increasing its efficiency, reducing production costs, environmental pollution, and chemical use. Among these microbial communities, lactic acid bacteria (LAB) are considered an interesting candidate to be formulated and applied as effective microbes. Indeed, these bacteria are approved by the European Food Safety Authority (EFSA) and Food and Drug Administration (FDA) as Qualified Presumption of Safety statute and Generally Recognized as Safe for various applications. To do so, this review comes as a road map for future research, which addresses the different steps included in LAB formulation as biocontrol, bioremediation, or plant growth promoting agents from the isolation process to their field application passing by the different identification methods and their various uses. The plant application methods as well as challenges limiting their use in agriculture are also discussed.
Asunto(s)
Lactobacillales , Desarrollo de la Planta , Lactobacillales/metabolismo , Lactobacillales/crecimiento & desarrollo , Plantas/microbiología , Biodegradación Ambiental , Agricultura/métodos , Microbiología del SueloRESUMEN
The aim of this research was to determine the effect of pectin coating made with essential oils and/or extracts of Thymus vulgaris (thyme) and Thymbra spicata (thymbra) on the preservation of aerobically packaged sliced bolognas during cold storage. The treatment made with essential oils resulted in a reduction of 1.73 log CFU/g of Salmonella typhimurium ATCC 14028. Also, pectin coating made with essential oil-treated sliced bolognas had the lowest total mesophilic bacteria (6.27 log CFU/g), and total lactic acid bacteria (1.72 CFU/g), in comparison to non-treated bolognas, with 7.65 log CFU/g for total mesophilic bacteria and 4.99 log CFU/g for lactic acid bacteria. Application of an emulsion significantly (P < 0.05) affected L*(lightness), a*(redness), and b*(yellowness) values. The essential oil treatment had the highest TBARS values at the end of the storage period. The pH was not affected by the treatment (P > 0.05), but storage had a significant (P < 0.05) effect on the pH values.
Asunto(s)
Películas Comestibles , Productos de la Carne/microbiología , Aceites Volátiles , Pectinas , Color , Microbiología de Alimentos , Embalaje de Alimentos/métodos , Conservación de Alimentos/métodos , Lactobacillales/crecimiento & desarrollo , Lamiaceae/química , Salmonella typhimurium/crecimiento & desarrollo , Thymus (Planta)/químicaRESUMEN
The contribution of sustainably food processing to healthy intestinal microbial functions is of recent acquisition. The sourdough fermentation fits well with the most sustainable bread making. We manufactured baker's yeast (BYB) and sourdough (t-SB30) breads, which first underwent to an in-depth characterization. According to nutritional questionnaires, we selected 40 volunteers adhering to the Mediterranean diet. Data on their fecal microbiota and metabolome allowed the selection of two highly representative fecal donors to separately run the Twin Mucosal-SHIME (Twin M-SHIME) under 2-week feeding with BYB and t-SB30. Bread feeding did not affect the microbial composition at phylum and family levels of both donors, in all Twin M-SHIME colon tracts, and lumen and mucosal compartments. The genus core microbiota showed few significant fluctuations, which regarded the relative abundances of Lactobacillus and Leuconostoc according to feeding with BYB and t-SB30, respectively. Compared with BYB, the content of all short chain fatty acids (SCFA), and isovaleric and 2-methylbutyric acids significantly increased with t-SB30 feeding. This was evident for all Twin M-SHIME colon tracts and both donors. The same was found for the content of Asp, Thr, Glu, GABA, and Orn. The bread characterization made possible to identify the main features responsible for this metabolic response. Compared with BYB, t-SB30 had much higher contents of resistant starch, peptides, and free amino acids, and an inhomogeneous microstructure. We used the most efficient approach to investigate a staple food component, excluding interferences from other dietary factors and attenuating human physiology overlaps. The daily consumption of sourdough bread may promote the healthy microbiota metabolism at colon level. IMPORTANCE Knowledge on environmental factors, which may compose the gut microbiota, and drive the host physiology and health is of paramount importance. Human dietary habits and food compositions are pivotal drivers to assemble the human gut microbiota, but, inevitably, unmapped for many diet components, which are poorly investigated individually. Approximately 30% of the human diet consists of fermented foods and beverages. Bread, a fermented/leavened food, is a basic component of the human diet. Its potential effect on gut microbiota composition and functionality is challenging. In this study, we industrially made baker's yeast and sourdough breads, which were used to feed the Twin Mucosal-SHIME, a worldwide scientifically validated gastrointestinal simulator. Only the consumption of sourdough bread has the potential to enhance the synthesis of short chain fatty acids and free amino acids at the colon level.
Asunto(s)
Pan/análisis , Colon/microbiología , Microbioma Gastrointestinal , Lactobacillales/metabolismo , Adulto , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Bacterias/metabolismo , Pan/microbiología , Estudios de Cohortes , Colon/metabolismo , Heces/microbiología , Femenino , Fermentación , Tracto Gastrointestinal/metabolismo , Tracto Gastrointestinal/microbiología , Humanos , Lactobacillales/crecimiento & desarrollo , Masculino , Persona de Mediana Edad , Saccharomyces cerevisiae/metabolismo , Adulto JovenRESUMEN
Lactic acid can synthesize high value-added chemicals such as poly lactic acid. In order to further minimize the cost of lactic acid production, some effective strategies (e.g., effective mutagenesis and metabolic engineering) have been applied to increase productive capacity of lactic acid bacteria. In addition, low-cost cheap raw materials (e.g., cheap carbon source and cheap nitrogen source) are also used to reduce the cost of lactic acid production. In this review, we summarized the recent developments in lactic acid production, including efficient strain modification technology (high-efficiency mutagenesis means, adaptive laboratory evolution, and metabolic engineering), the use of low-cost cheap raw materials, and also discussed the future prospects of this field, which could promote the development of lactic acid industry.
Asunto(s)
Microbiología Industrial , Ácido Láctico/biosíntesis , Lactobacillales/crecimiento & desarrollo , Ingeniería Metabólica , Lactobacillales/genéticaRESUMEN
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.
Asunto(s)
Antibacterianos/farmacología , Queso/microbiología , Farmacorresistencia Microbiana , Eritromicina/farmacología , Lactobacillales/crecimiento & desarrollo , Plásmidos/genética , Animales , Lactobacillales/efectos de los fármacos , Lactobacillales/aislamiento & purificaciónRESUMEN
Nutritional dependencies, especially those regarding nitrogen sources, govern numerous microbial positive interactions. As for lactic acid bacteria (LAB), responsible for the sanitary, organoleptic, and health properties of most fermented products, such positive interactions have previously been studied between yogurt bacteria. However, they have never been exploited to create artificial cocultures of LAB that would not necessarily coexist naturally, i.e., from different origins. The objective of this study was to promote LAB positive interactions, based on nitrogen dependencies in cocultures, and to investigate how these interactions affect some functional outputs, e.g., acidification rates, carbohydrate consumption, and volatile-compound production. The strategy was to exploit both proteolytic activities and amino acid auxotrophies of LAB. A chemically defined medium was thus developed to specifically allow the growth of six strains used, three proteolytic and three nonproteolytic. Each of the proteolytic strains, Enterococcus faecalis CIRM-BIA2412, Lactococcus lactis NCDO2125, and CIRM-BIA244, was cocultured with each one of the nonproteolytic LAB strains, L. lactis NCDO2111 and Lactiplantibacillus plantarum CIRM-BIA465 and CIRM-BIA1524. Bacterial growth was monitored using compartmented chambers to compare growth in mono- and cocultures. Acidification, carbohydrate consumption, and volatile-compound production were evaluated in direct cocultures. Each proteolytic strain induced different types of interactions: strongly positive interactions, weakly positive interactions, and no interactions were seen with E. faecalis CIRM-BIA2412, L. lactis NCDO2125, and L. lactis CIRM-BIA244, respectively. Strong interactions were associated with higher concentrations of tryptophan, valine, phenylalanine, leucine, isoleucine, and peptides. They led to higher acidification rates, lower pH, higher raffinose utilization, and higher concentrations of five volatile compounds. IMPORTANCE Interactions of lactic acid bacteria (LAB) are often studied in association with yeasts or propionibacteria in various fermented food products, and the mechanisms underlying their interactions are being quite well characterized. Concerning interactions between LAB, they have mainly been investigated to test antagonistic interactions. Understanding how they can positively interact could be useful in multiple food-related fields: production of fermented food products with enhanced functional properties or fermentation of new food matrices. This study investigated the exploitation of the proteolytic activity of LAB strains to promote positive interactions between proteolytic and nonproteolytic strains. The results suggest that proteolytic LAB do not equally stimulate nonproteolytic LAB and that the stronger the interactions between LAB are, the more functional outputs we can expect. Thus, this study gives insight into how to create new associations of LAB strains and to guarantee their positive interactions.
Asunto(s)
Lactobacillales/metabolismo , Interacciones Microbianas , Nitrógeno/metabolismo , Aminoácidos/metabolismo , Animales , Técnicas de Cocultivo , Microbiología de Alimentos , Lactobacillales/crecimiento & desarrollo , Lactosa/metabolismo , Lupinus , Leche , Péptidos , Proteolisis , Rafinosa/metabolismo , Sacarosa/metabolismo , Compuestos Orgánicos Volátiles/metabolismoRESUMEN
Inoculation of sourdough allows the fermentation medium to be dominated by desired microorganisms, which enables determining the kinetics of the conversion of chemical compounds by individual microorganisms. This knowledge may allow the design of functional food products with health features dedicated to consumers with special needs. The aim of the study was to assess the dynamics of transformations of fermentable oligosaccharide, disaccharide, monosaccharide and polyol (FODMAP) compounds from wheat flour as well as their antioxidant activity during inoculated and spontaneous sourdough fermentation. The FODMAP content in grain products was determined by the fructan content with negligible amounts of sugars and polyols. To produce a low-FODMAP cereal product, the fermentation time is essential. The 72 h fermentation time of L. plantarum-inoculated sourdough reduced the FODMAP content by 91%. The sourdough fermentation time of at least 72 h also positively influenced the content of polyphenols and antioxidant activity, regardless of the type of fermentation. The inoculation of both L. plantarum and L. casei contributed to a similar degree to the reduction in FODMAP in sourdough compared to spontaneous fermentation.
Asunto(s)
Antioxidantes/metabolismo , Harina/análisis , Ácido Láctico/metabolismo , Lactobacillales/metabolismo , Polímeros/metabolismo , Polifenoles/metabolismo , Triticum/metabolismo , Carbohidratos/química , Fermentación , Lactobacillales/crecimiento & desarrollo , Triticum/microbiologíaRESUMEN
Artisanal products support the conservation of the indigenous biodiversity of food microbiomes, although they do not always comply to quality and hygienic requirements for the dairy industry. This study describes the development of an autochthonous starter culture to produce Matsoni, a traditional Georgian fermented milk. To this end, strains of lactic acid bacteria isolated from artisanal Matsoni samples were used to design a starter formulation reproducing the dominant microbial diversity, also preserving quality characteristics and ensuring the safety of the product. As a result, strains that represent the acidifying portion of the starter (Lactobacillus delbrueckii subsp. lactis, L. delbrueckii subsp. bulgaricus and Streptococcus thermophilus) were combined in different ratios and strain combinations, together with cultures of Lactobacillus rhamnosus that were chosen for their potential beneficial traits. The strain association acting better in milk cultures at laboratory scale was selected as starter culture for the production of Matsoni in pilot-scale industrial trials.
Asunto(s)
Productos Lácteos Cultivados/microbiología , Productos Lácteos Cultivados/análisis , Fermentación , Microbiología de Alimentos , Georgia (República) , Concentración de Iones de Hidrógeno , Lactobacillales/clasificación , Lactobacillales/crecimiento & desarrollo , Lactobacillales/aislamiento & purificación , Lactobacillales/metabolismo , Probióticos , GustoRESUMEN
This study investigated the effect of inoculating Lactobacillus (L.) plantarum PS-8 in fermentation of alfalfa silages. We monitored the fermentation characteristics and bacterial population dynamics during the ensiling process. PacBio single molecule real time sequencing was combined with propidium monoazide (PMA) treatment to monitor the viable microbiota dynamics. We found that inoculating L. plantarum PS-8 may improve the silage quality by accelerating acidification, reducing the amounts of clostridia, coliform bacteria, molds and yeasts, elevating the protein and organic acid contents (except butyrate), and enhancing lactic acid bacteria (LAB) while suppressing harmful microorganisms. Some significant differential abundant taxa were found between the PMA-treated and non-treated microbiota. For example, the relative abundances of L. brevis, L. plantarum, and Pediococcus pentosaceus were significantly higher in the PMA-treated group than the non-PMA-treated group, suggesting obvious differences between the viable and non-viable microbiota. It would thus be necessary to distinguish between the viable and non-viable microbial communities to further understand their physiological contribution in silage fermentation. By tracking the dynamics of viable microbiota in relation with changes in the physico-chemical parameters, our study provided novel insights into the beneficial effects of inoculating L. plantarum PS-8 in silage fermentation and the physiological function of the viable bacterial communities.
Asunto(s)
Bacterias/crecimiento & desarrollo , Bacterias/metabolismo , Hongos/crecimiento & desarrollo , Lactobacillus plantarum/crecimiento & desarrollo , Medicago sativa/microbiología , Microbiota , Ensilaje/microbiología , Azidas/análisis , Bacterias/clasificación , Bacterias/genética , Biodiversidad , ADN Bacteriano , Fermentación , Lactobacillales/crecimiento & desarrollo , Medicago sativa/metabolismo , Propidio/análogos & derivados , Propidio/análisisRESUMEN
Co-infections of mammalian hosts with intestinal helminths and bacterial pathogens are common, especially in areas with inadequate sanitation. Interactions between co-infecting species and host microbiota can cause significant changes in host immunity, disease severity, and pathogen transmission, requiring unique treatment for each case. A greater understanding of the influences of parasite-bacteria co-infections will improve diagnosis and therapeutic approaches to control infectious diseases. To study the influence of the trematode parasite Echinostoma caproni on commensal and pathogenic bacteria in the mouse gut, we examined the abundance of intestinal lactic acid bacteria and Salmonella enterica serovar Typhimurium in control mice not exposed to E. caproni (P-) or S. Typhimurium (S-), E. caproni-infected (P+S-), S. Typhimurium-infected (P-S+), and E. caproni-S. Typhimurium co-infected (P+S+) mice, and determined bacterial burdens in the livers and spleens of the P-S+ and P+S+ mice. We also examined a subset of P+S- and P+S+ mice for survival and the relative location of E. caproni in the small intestine. The numbers of presumptive lactic acid bacteria were significantly higher in the P+S+ and P-S+ mice compared to the uninfected mice, and S. Typhimurium colonization in the liver and spleen was significantly reduced in the P+S+ mice compared to the P-S+ mice. Echinostoma caproni were located anteriorly in the intestine of P+S- mice, while in the P+S+ mice, the parasites were distributed more posteriorly. Survival of E. caproni was unaffected in either group. The results of our study suggest that E. caproni facilitates a higher abundance of presumptive lactic acid bacteria in the mouse intestine and reduces colonization of S. Typhimurium in the liver and spleen of the co-infected host.
Asunto(s)
Echinostoma/fisiología , Intestino Delgado/microbiología , Intestino Delgado/parasitología , Lactobacillales/crecimiento & desarrollo , Salmonella typhimurium/crecimiento & desarrollo , Animales , Biomphalaria/parasitología , Echinostoma/aislamiento & purificación , Heces/microbiología , Heces/parasitología , Femenino , Lactobacillales/aislamiento & purificación , Hígado/microbiología , Hígado/parasitología , Metacercarias/aislamiento & purificación , Metacercarias/fisiología , Ratones , Ratones Endogámicos ICR , Método de Montecarlo , Salmonella typhimurium/aislamiento & purificación , Bazo/microbiología , Bazo/parasitologíaRESUMEN
Postbiotic RS5, produced by Lactiplantibacillus plantarum RS5, has been identified as a promising alternative feed supplement for various livestock. This study aimed to lower the production cost by enhancing the antimicrobial activity of the postbiotic RS5 by improving the culture density of L. plantarum RS5 and reducing the cost of growth medium. A combination of conventional and statistical-based approaches (Fractional Factorial Design and Central Composite Design of Response Surface Methodology) was employed to develop a refined medium for the enhancement of the antimicrobial activity of postbiotic RS5. A refined medium containing 20 g/L of glucose, 27.84 g/L of yeast extract, 5.75 g/L of sodium acetate, 1.12 g/L of Tween 80 and 0.05 g/L of manganese sulphate enhanced the antimicrobial activity of postbiotic RS5 by 108%. The cost of the production medium was reduced by 85% as compared to the commercially available de Man, Rogosa and Sharpe medium that is typically used for Lactobacillus cultivation. Hence, the refined medium has made the postbiotic RS5 more feasible and cost-effective to be adopted as a feed supplement for various livestock industries.
Asunto(s)
Antiinfecciosos/metabolismo , Medios de Cultivo/química , Lactobacillus plantarum/crecimiento & desarrollo , Medios de Cultivo/análisis , Medios de Cultivo/síntesis química , Fermentación , Lactobacillaceae/crecimiento & desarrollo , Lactobacillaceae/metabolismo , Lactobacillales/crecimiento & desarrollo , Lactobacillales/metabolismo , Lactobacillus plantarum/metabolismoRESUMEN
Riboflavin (vitamin B2) is a vitamin of the B group involved in essential biological pathways, including redox reactions and the electron transport chain. Some lactic acid bacteria (LAB) can synthesize riboflavin and this capability is strain-dependent. In the last years, a growing interest has focused on the selection of riboflavin-overproducing food-grade LAB for the vitamin biofortification of fermented foods, as well as for the formulation of innovative functional products.In this chapter we report fast and inexpensive techniques in order to (1) screen LAB isolates able to produce riboflavin from different matrices, (2) select spontaneous roseoflavin-resistant riboflavin overproducing strains, and (3) quantify vitamin B2 in culture media by fluorescence detection.These protocols could be useful to select new overproducing strains and/or species from different ecological niches, as well as to optimize the conditions for vitamin bioproduction.
Asunto(s)
Lactobacillales/crecimiento & desarrollo , Riboflavina/análogos & derivados , Riboflavina/análisis , Técnicas Bacteriológicas , Medios de Cultivo/química , Farmacorresistencia Bacteriana , Alimentos Fermentados/microbiología , Fluorescencia , Lactobacillales/metabolismo , Riboflavina/farmacologíaRESUMEN
Probiotics often play an important role in improving gut health in chickens through multiple mechanisms, including enhancement of tight junctions, nutrient acquisition, niche colonization, or coaggregation with enteric pathogens. The objective of this study was to characterize lactic acid bacteria (LAB) isolated from the gut of healthy broiler chickens for a number of phenotypes that might be indicative of good probiotic potentials. A total 40 bacterial isolates were isolated from 3-week-old chickens using Man, Rogosa and Sharpe (MRS) agar plates. The bacterial isolates were evaluated in vitro for motility, autoaggregation, pathogen inhibition, pH of overnight culture, growth on different agar plates, and their impact on gut integrity. Selected isolates were genotyped by sequencing the 16S-23S rRNA gene intergenic region. Based on the phenotype and genotype, we identified 20 potential probiotic (PP) isolates that belong to LAB. Multivariate analysis showed that PP isolates were positively correlated with parameters such as growth on MRS agar plate (pH 5.5), pathogen inhibition, and autoaggregation. However, growth on MacConkey agar plates, supernatant pH, motility, and transepithelial electrical resistance were negatively correlated with the PP isolates. Furthermore, in vivo study needs to be performed for evaluation of the utility of these probiotic candidates in poultry production.