Search Results (21)

Fermented foods such as table olives are produced through a spontaneous process that has been improved over the years, ensuring the safety and quality of the final product. The aim of the present work was to study the action of starter cultures of lactic acid bacteria (Lacticaseibacillus rhamnosus GG ATCC53103, Levilactobacillus brevis ATCC8287, and Lactiplantibacillus plantarum ATCC14917) which were previously shown to have probiotic and antioxidant potential during the fermentation of natural Greek-style black olives (Kalamata) in brine containing 6% (w/v) NaCl at a temperature of 20 °C for a period of 150 days. At a molecular level, the main metabolites in every fermentation process were identified using an HPLC method. The results showed that the concentration of the metabolites increased gradually, developing a stable pattern after the 90th day of fermentation. In addition, the DL-p-hydroxyphenyllactic acid (OH-PLA) was identified as the phenolic acid with the highest concentration, independently of the selected starter culture. Microbial genomic DNA was also extracted from the olives’ surface at the final stages of fermentation (150 days) and was subjected to 16S rRNA sequencing using the Nanopore MinION™ NGS tool, enabling a comprehensive analysis of the microbial community. According to the findings, the most abundant genera were Lactobacillus and Leuconostoc. To the best of our knowledge, this is the first study exploring these particular starters for olive fermentation. Full article

The aim(目的) of this study was to create(创建) various formulations of yogurt enriched with freeze(冻结)-dried adjuncts, namely(即) (i) probiotic Lactobacillus plantarum ATCC 14917 culture(文化), and (ii) L. plantarum ATCC 14917 fermented black chokeberry juice, along with a commercial(商业) starter culture(文化). The goal was to enhance(提高) functionality and optimize the nutritional(营养) value(价值) of the products. These new yogurt-style(风格) formulations were subsequently(随后) compared with commercially produced yogurt. All products demonstrated(演示) favorable(有利) physicochemical properties, and the probiotic strain(应变) consistently(一贯) maintained viable(可行) levels exceeding 7 log(日志) cfu/g throughout(遍及) the entire(整个) storage(存储) period(时期). The fermented milk produced with the adjunct-free L. plantarum cells, as well as the yogurt produced with the proposed(提出) lactobacilli-fermented chokeberry juice, exhibited the highest lactic acid(酸) production(生产) (1.44 g/100 g yogurt by the end of storage(存储)). Levels of syneresis were observed at lower(较低) values(价值) in yogurt produced with freeze(冻结)-dried fermented chokeberry juice. Yogurts prepared(准备) with the lactobacilli-fermented freeze(冻结)-dried chokeberry juice displayed elevated total(总) phenolic content(内容) and antioxidant capacity(容量) (25.74 µg GAE/g and 69.05 µmol TE/100 g, respectively(分别)). Furthermore, sensory tests revealed a distinctive(鲜明) fruity flavor(风味) in samples incorporating fermented juice. The results demonstrate(演示) that probiotic L. plantarum-fermented chokeberry juice enhances(提高) both the antioxidant capacity(容量) and the viability of beneficial(有益) bacteria(细菌) in yogurt while it can be readily(欣然) applied and commercialized, especially in the form of a freeze(冻结)-dried formulation. Full article

The content of polyphenols, lactic acid, and antioxidant properties in fermented juice increases more at 30 °C than at 35 °C during the lactic fermentation process in butanol extract and broccoli juice. The concentration of polyphenols is expressed by phenolic acid equivalents as gallic acid-Total Phenolic Content (TPC), ferulic acid (CFA), p-cumaric acid (CPA), sinapic acid (CSA), and caffeic acid (CCA). The polyphenols present in fermented juice exhibit antioxidant properties and the ability to reduce free radicals using total antioxidant capacity (TAC) assay, while also the percentage of the DPPH (2,2-Diphenyl-1-picrylhydrazyl) radical and ABTS (2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) cation radical scavenging activity. Lactic acid concentration (LAC), total flavonoid content as quercetin equivalents (QC), and acidity increases during the work of Lactiplantibacillus plantarum (previously Lactobacillus plantarum) in broccoli juice. The pH was monitored during the process of fermentation in both temperatures (30 °C and 35 °C). Densitometric measurements of lactic bacteria (LAB) showed increasing concentration at 30 °C and 35 °C after 100 h (~4 h), but the value concentration dropped after 196 h. The Gram staining showed only Gram-positive bacilli Lactobacillus plantarum ATCC 8014. The Fourier transform infrared (FTIR) spectrum for the fermented juice showed the characteristic carbon–nitrogen vibrations that may originate from glucosinolates or isothiocyanates. Among the fermentation gases, more CO₂ was released from fermenters at 35 °C than at 30 °C. The biopreservation used Lactiplantibacillus plantarum to prevent the problem of food waste of plant origin. The probiotic bacteria used in fermentation have a very beneficial effect on health and the human body. Full article

This study was aimed at screening potential probiotic candidates to enhance the antimicrobial activity of Artemisia argyi against foodborne pathogens. Ten LAB strains were isolated from natural Artemisia argyi fermentation liquor (AAFL) and assessed for safety and antimicrobial ability. Therein, Lactiplantibacillus plantarum WLPL01, Lacticaseibacillus casei WLCA01, WLCA02, and WLCA03, and Lactobacillus harbiness WLHA01 were further evaluated for their potential probiotic properties (gastrointestinal tolerance and adhesion capacity). The results suggested that L. plantarum WLPL01 exhibited excellent properties and was, therefore, selected as the starter for A. argyi leaves fermentation. Then, L. plantarum WLPL01-fermented AAFL (AAFL-LP) was further investigated for its antimicrobial activity against foodborne pathogens. The results demonstrated that the inhibitory effect of AAFL-LP to foodborne pathogens, such as Listeria monocytogenes CMCC54007, Salmonella Typhimurium ATCC 13311, and Candida albicans ATCC 14053, was enhanced when compared to spontaneously fermented AAFL (AAFL-spontaneous). In addition, an analysis of the whole genome of L. plantarum WLPL01 revealed the presence of 13.9 kb long and 16 plantaricin-encoding loci (pln locus), and the increased antimicrobial activities of AAFL-LP might correlate with the production of bacteriocin. Our results indicate that L. plantarum WLPL01 can be used as a starter for Artemisia argyi fermentation to enhance its antimicrobial activity against foodborne pathogens. Full article

At present, there is an increasing interest in beverages of non-dairy origin, as alternatives to those based on milk, but having similar health-promoting properties. Fermentation with specific bacteria or consortia may enhance the functionality of these products. In our study, selected lactic acid bacteria, that have been previously shown to possess functional properties (antimicrobial activity, probiotic potential), were used for the fermentation of wheat bran combined with root vegetables. Strains were investigated for their safety, while the obtained beverages were characterized in terms of microbial content, physical, chemical, nutritional, and functional properties. None of the strains harbors virulence genes, but all of them possess genes for survival at low pH, starch metabolism, and vitamin biosynthesis. Three strains (Lactiplantibacillus plantarum BR9, L. plantarum P35, and Lactobacillus acidophilus IBB801) and two substrates (5% wheat bran with 10% red beetroot/carrots) were selected based on a preliminary assessment of the beverage’s sensory acceptability. These strains showed good growth and stability over time in the stored beverages. No enterobacteria were detected at the end of fermentations, while the final pH was, in most cases, below 3.5. Free phenolics, flavonoids, and DPPH scavenging effect increased during fermentation in all drinks, reaching 24h values that were much higher than in the unfermented substrates. Most of the obtained drinks were able to prevent the growth of certain pathogens, including Listeria monocytogenes ATCC 19111, Salmonella enterica ATCC 14028, Staphylococcus aureus ATCC 25923, and Escherichia coli ATCC 25922. The obtained beverages would combine the nutritiveness of the raw ingredients with the beneficial effect of fermentation (increasing shelf life, health-promoting effect, pleasant flavor, etc.). They would also fill a gap in the non-dairy probiotics sector, which is constantly increasing due to the increasing number of vegan people or people that cannot consume dairy products. Full article

Fermented soymilk (soymilk yogurt) was made by fermenting soymilk with five probiotic bacterial strains (Lactobacillus plantarum ATCC 14917, Lactobacillus casei DSM 20011, Lactobacillus acidophilus ATCC 20552, Lactococcus thermophilus DSM 20259, and Bifidobacterium longum B41409) that were used as monocultures and combined with them as consortia cultures. Seven pathogenic strains, E. coli O157H7, S. aureus As4, S. typhimurium As3, S. shigae As2, L. monocytogenes As1, P. aeruginosa ATCC 27853, and B. cereus Dsmz 345, were used to study the antibacterial activity of fermented soymilk by agar well diffusion assay. Results indicated that Gram-negative pathogenesis was more sensitive to probiotic cultures than Gram-positive pathogenesis. E. coli O15H7, S. typhimirium As3, and Shigella shigae As2 were more sensitive to probiotic cultures, presenting inhibition zone diameters (IZA) ranging from 10 to 20 mm, 12 to 16 mm, and 10 to 16 mm, respectively. At the same time, P. aeruginosa Atcc 27853 showed the lowest (IZA), ranging from 3 mm to 8 mm. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined at various concentrations of soymilk fermented by T1, T4, and T5, ranging from 0.031 mg/mL to 1 mg/mL against pathogenic bacterial strains. The sensory properties of FSM were evaluated, and sensory analysis during soymilk fermentation showed significant improvement. The effect of shelf life (storage period) on FSM quality and properties was evaluated; during shelf life (storage period), FSM saved its properties and quality after 28 days of cold storage. Finally, it was stated that the soymilk yogurt can be used as a substitute for buffalo and cow milk for therapeutic feeding in the future. Full article

Acheta domesticus (L.1758) has been recently accepted by the European Union as a novel food, being the third insect that has been approved for human consumption. Nowadays, researchers’ attention is focused on exploiting new protein sustainable sources, and, therefore, insect flour has gained more and more interest. Organic acids, fatty acids, amino acids, aroma volatile compounds, and minerals were analyzed through HPLC-RID (High-performance liquid chromatography), GC-MS (Gas chromatography-mass spectrometry), LC-MS (Liquid chromatography–mass spectrometry), ITEX/GC-MS and AAS (Atomic Absorption Spectrophotometry), respectively. Fermentation of the insect flour with Lactobacillus plantarum ATCC 8014 strain (Lp) leads to an increase in organic acids such as lactic, acetic, and oxalic, whilst citric acid decreases its value. SFA (saturated fatty acids) and MUFA (monosaturated fatty acids) groups were positively influenced by Lp fermentation; meanwhile, PUFA (polysaturated fatty acids) decreased during fermentation. A positive trend was observed for amino acids, aroma volatile content, and minerals enhancement during insect sourdough fermentation, mainly at 24 h of fermentation. Acheta domesticus (A. domesticus) sourdough fermentation represents a new tool that needs to be further exploited aiming to improve the nutritional qualities of the final products. Full article

Lactobacilli constitute the dominant microbiota in many fermented foods and comprise widely used probiotics. However, these bacteria cause rare infections mostly in diabetic and immunocompromised subjects in presence of risk factors such as prosthetic hearth valves and dental procedures or caries. The scope of this survey was re-assessing the pathogenic potential of lactobacilli based on the infection case reports published in the last three years. In 2019, 2020, and 2021, total of 17, 15, and 16 cases, respectively, including endocarditis, bacteremia, and other infections, were reported. These annual numbers are higher than those observed previously. Lacticaseibacillus rhamnosus (13 cases), comprising strain GG (ATCC 53103) with established applications in healthcare, L. paracasei (7 cases), Lactobacillus acidophilus (5 cases), L. jensenii (5 cases), Lactiplantibacillus plantarum (3 cases), L. paraplantarum, L. delbrueckii subsp. delbrueckii, L. gasseri, L. paragasseri, Limosilactobacillus fermentum, and L. reuteri (1 case each) were involved. Virulence characterization of two strains that caused infections, a derivative of L. rhamnosus GG and L. paracasei LP10266, indicated that increased biofilm-forming capacity favors pathogenicity and it is determined by variable genetic traits. This survey highlights that the strains of lactobacilli that cause infections are little characterized genetically. Instead, to avoid that these bacteria become a hazard, genetic stability should be periodically re-evaluated by whole genome sequencing (WGS) to ensure that only non-pathogenic variants are administered to vulnerable individuals. Full article

Lactobacilli are Gram-positive aerotolerant organisms that comprise the largest genus of Lactic Acid Bacteria (LAB). Most lactobacilli are devoid of the antioxidant enzymes, superoxide dismutases, and catalases, required for protection against superoxide radicals and hydrogen peroxide (H₂O₂), respectively. However, some lactobacilli can accumulate millimolar concentrations of intracellular manganese and spare the need for superoxide dismutase, while others possess non-heme catalases. L. plantarum is associated with plant materials and plays an important role in fermented foods and gut microbiomes. Therefore, understanding the effects of the environment on the growth and survival of this organism is essential for its success in relevant industrial applications. In this report, we investigated the physiological role of Mn-catalase (MnKat) in Lactobacillus plantarum ATCC 14431. To this end, we compared the physiological and morphological properties of a ΔMnkat mutant strain and its isogenic parental strain L. plantarum ATCC 14431. Our data showed that the MnKat is critical for the growth of L. plantarum ATCC 14431 in the presence of oxygen and resistance to H₂O₂. The aerobic growth of the mutant in presence or absence of H₂O₂ was improved in the Mn-rich medium (APT) as compared to the growth in MRS medium. Furthermore, under aerobic conditions the mutant strain possessed atypical cellular morphology (i.e., shorter, and fatter). In conclusion, the MnKat of L. plantarum ATCC 14431 is important for aerobic growth, protection against H₂O₂, and maintenance of the rod-shaped cell morphology under aerobic conditions. Full article

Plant-based foods contain bioactive compounds such as polyphenols that resist digestion and potentially benefit the host through interactions with their resident microbiota. Based on previous observations, we hypothesized that the probiotic Lactobacillus plantarum interacts with cranberry polyphenols and dietary oligosaccharides to synergistically impact its physiology. In this study, L. plantarum ATCC BAA-793 was grown on dietary oligosaccharides, including cranberry xyloglucans, fructooligosaccharides, and human milk oligosaccharides, in conjunction with proanthocyanidins (PACs) extracted from cranberries. As a result, L. plantarum exhibits a differential physiological response to cranberry PACs dependent on the carbohydrate source and polyphenol fraction introduced. Of the two PAC extracts evaluated, the PAC1 fraction contains higher concentrations of PACs and increased growth regardless of the oligosaccharide, whereas PAC2 positively modulates its growth during xyloglucan metabolism. Interestingly, fructooligosaccharides (FOS) are efficiently utilized in the presence of PAC1, as this L. plantarum strain does not utilize this substrate typically. Relative to glucose, oligosaccharide metabolism increases the ratio of secreted acetic acid to lactic acid. The PAC2 fraction differentially increases this ratio during cranberry xyloglucan fermentation compared with PAC1. The global transcriptome links the expression of putative polyphenol degradation genes and networks and metabolic phenotypes. Full article

Background: the antagonism activity of lactic acid bacteria metabolites has the potential to prevent fungal growth on mango. Methods: the potential of developing natural disinfectant while using watermelon rinds (WR), pineapple (PP), orange peels (OP), palm kernel cake (PKC), and rice bran (RB), via lacto-fermentation was investigated. The obtained lactic acid bacteria (LAB) metabolites were then employed and the in vitro antifungal activity toward five spoilage fungi of mango was tested through liquid and solid systems. Besides, the effect of the produced disinfectant on the fungal growth inhibition and quality of mango was investigated. Results: the strains Lactobacillus plantarum ATCC8014 and Lactobacillus fermentum ATCC9338 growing in the substrates PKC and PP exhibited significantly higher in vitro antifungal activity against Colletotrichum gloeosporioides and Botryodiplodia theobromae as compared to other tested LAB strains and substrates. The in-situ results demonstrated that mango samples that were treated with the disinfectant produced from PKC fermented with L. plantarum and L. fermentum had the lowest disease incidence and disease severity index after 16 days shelf life, as well as the lowest conidial concentration. Furthermore, PKC that was fermented by L. fermentum highly maintained the quality of the mango. Conclusions: lactic acid fermentation of PKC by L. fermentum demonstrated a high potential for use as a natural disinfectant to control C. gloeosporioides and B. theobromae on mango. Full article

Lactobacillus plantarum ATCC 8014 was used to ferment quinoa flour, in order to evaluate its influence on the nutritional and rheological characteristics of both the sourdough and muffins. The quantification of carbohydrates and organic acids was carried out on a HPLC-RID system (high-performance liquid chromatography coupled with with refractive index detector), meanwhile HPLC-UV-VIS (high-performance liquid chromatography coupled with UV-VIS detector), AAS (Atomic absorption spectrophotometry), aluminum chloride colorimetric assay, Folin–Ciocalteu, and 1,1-Diphenyl-2-picrylhydrazyl radical scavenging activity (DPPH) methods were used to determine folic acid, minerals, flavonoids, total phenols, and radical scavenging activity, respectively. Two types of sourdough were used in this study: quinoa sourdough fermented with L. plantarum ATCC 8014 and quinoa sourdough spontaneous fermented. The first one influenced the chemical composition of muffins in terms of decreased content of carbohydrates, higher amounts of both organic acids and folic acid. Furthermore, higher amounts of flavonoids, total phenols and increased radical scavenging activity were recorded due to the use of Lactobacillus plantarum ATCC 8014 strain. These results indicate the positive effect of quinoa flour fermentation with the above strain and supports the use of controlled fermentation with lactic acid bacteria for the manufacturing of gluten free baked products. Full article

Sourdough fermentation presents several advantageous effects in bread making, like improved nutritional quality and increased shelf life. Three types of experiments aimed to evaluate comparatively the efficiency of two Lactobacillus (Lb.) strains, Lb. plantarum ATCC 8014 and Lb. casei ATCC 393, to metabolize different white wheat flour and soybeans flour combinations to compare their efficiency, together with/without Saccharomyces cerevisiae on sourdough fermentation. For this purpose, the viability, pH, organic acids, and secondary metabolites production were investigated, together with the dynamic rheological properties of the sourdough. During sourdough fermentation, LAB presented higher growth, and the pH decreased significantly from above pH 6 at 0 h to values under 4 at 24 h for each experiment. Co-cultures of LAB and yeast produced a higher quantity of lactic acid than single cultures, especially in sourdough enriched with soy-flour. In general, sourdoughs displayed a stable, elastic-like behavior, and the incorporation of soy-flour conferred higher elasticity in comparison with sourdoughs without soy-flour. The higher elasticity of sourdoughs enriched with soy-flour can be attributed to the fact that through frozen storage, soy proteins have better water holding capacity. In conclusion, sourdough supplemented with 10% soy-flour had better rheological properties, increased lactic, acetic, and citric acid production. Full article

Lactobacilli are used in food because of their beneficial effect on human health and their biopreservative activity in matured meat products. The objective of this work was to study the growth kinetics of Lactobacillus plantarum ATCC 8014 by submerged fermentation at laboratory and bench scales, using a culture medium based on bovine blood plasma (BBP) with hydrolyzed proteins, and to evaluate the maturational effects and sensory properties conferred by the obtained biomass on a matured meat product (pepperoni). At bench scale, it was found that the maximum viable biomass concentration of L. plantarum was 9.58 log CFU/mL, which was higher than what was found in the MRS culture medium (9.53 log CFU/mL). The mathematical model proposed appropriately described the L. plantarum growth kinetics and carbohydrate dynamics during fermentation at laboratory and bench scales in hydrolyzed BBP medium. The application of viable L. plantarum biomass propagated on this medium did not show statistically significant differences during pepperoni maturation compared to the product made with the commercial starter culture. The sensory panel found no differences in the evaluated sensory attributes between these two products. The L. plantarum biomass obtained on this medium can be used successfully in maturation processes in different meat matrices. Full article

A direct bioconversion of gelatinized starchy waste (GSW) to lactic acid by amylolytic lactic acid bacterium Lactobacillus plantarum S21 was investigated. Corn steep liquor (CSL) was selected as the most suitable low-cost nitrogen source for replacing yeast extract, beef extract, and peptone in De Man, Rogosa and Sharpe (MRS) medium. Plackett–Burman design results indicated that GSW and CSL were the two most nutrients that significantly influence lactic acid production, among eight medium components, including GSW, CSL, K₂HPO₄, CH₃COONa, (NH₄)₂HC₆H₅O₇, MgSO₄, MnSO₄, and Tween 80. A new low-cost medium containing only GSW (134.4 g/L) and CSL (187.7 g/L) was achieved as omitting other six components from the optimized medium had no effect on lactic acid yield. Batch fermentation at 37 °C both in 1 L and 10 L jar fermenters showed non-significantly different productivity. A by-product, maltose-forming α-amylase, was successfully achieved up to 96% recovery yield using an ultrafiltration unit equipped with a 50 kDa cut-off membrane. Crude lactic acid exhibited the additional benefit of antimicrobial activity against food and feed pathogens Salmonella enterica serovar Typhimurium TISTR 292, Vibrio cholerae TH-001, and also E. coli ATCC 25922. This study presents a promising bioprocess for the simultaneous production of lactic acid, and a value-added food enzyme, using only two industrial wastes, GSW and CSL, as the medium components. Full article