Lactic Acid Bacteria Strains Research Articles

Host-derived lactic acid bacteria alleviate short beak and dwarf syndrome by preventing bone loss, intestinal barrier disruption, and inflammation

Short-beak and dwarf syndrome (SBDS) is caused by novel goose parvovirus (NGPV) infection, which leads to farm economic losses. Our research aimed to investigate the potential of administering isolated lactic acid bacteria (LAB) in alleviating SBDS in ducks. Eight wild LAB strains were isolated from duck feces and their biosecurity was investigated in both duck embryo fibroblast (DEF) and live ducks. Moreover, the LAB strains exhibited no detrimental effects on bone metabolism levels and facilitated the tight junction proteins (TJPs) mRNA expression, and contributing to the mitigation of inflammation in healthy ducks. Subsequently, we conducted in vitrol and in vivo experiments to assess the impact of LAB on NGPV infection. The LAB strains significantly reduced the viral load of NGPV and downregulated the mRNA levels of pro-inflammatory factors in DEF. Additionally, LAB treatment alleviated SBDS in NGPV-infected ducks. Furthermore, LAB treatment alleviated intestinal damage, and reduced the inflammatory response, while also mitigating bone resorption in NGPV-infected ducks. In conclusion, the LAB strains isolated from duck feces have favorable biosecurity and alleviate SBDS in ducks, and the mechanism related to LAB improves intestinal barrier integrity, alleviates inflammation, and reduces bone resorption. Our study presents a novel concept for the prevention and treatment of NGPV, thereby establishing a theoretical foundation for the future development of probiotics in the prevention and treatment of NGPV.

Evaluating the Antagonistic Activity of Lactic Acid Bacteria in Cadaverine Production by Vibrio Strains during Co-Culture

Vibrio cholerae and Vibrio parahaemolyticus are common pathogens linked to human gastroenteritis, particularly in seafood like shrimp. This study investigated the impact of lactic acid bacteria on V. cholerae and V. parahaemolyticus regarding the production of cadaverine, a concerning compound. V. cholerae NCCP 13589 and V. parahaemolyticus ATCC 27969 were significant producers of amines in experiments conducted using white-leg shrimp (Litopenaeus vannamei) and lysine decarboxylase broth. Notably, the Lactiplantibacillus plantarum NCIMB 6105 and Leuconostoc mesenteroides ATCC 10830 lactic acid bacteria strains demonstrated a pronounced antagonistic effect on the production of biogenic amines by these food-borne pathogenic bacteria. The presence of lactic acid bacteria led to a substantial reduction in cadaverine production in the lysine decarboxylase broth and shrimp extract. The co-culture of two lactobacilli species reduced the cadaverine production in V. cholerae and V. parahaemolyticus by approximately 77 and 80%, respectively. Consequently, the favorable influence of lactic acid bacteria in curbing cadaverine production by food-borne pathogens presents clear advantages for the food industry. Thus, effectively managing these pathogens could prove pivotal in controlling the biogenic amine levels in shrimp.

Genomic and proteomic analyses reveal the reduction mechanism of hexavalent chromium by the culturing supernatant of strain Pediococcus acidilactici 13-7

This study used lactic acid bacteria with high antioxidative properties to screen for strains capable of reducing hexavalent chromium [Cr (VI)] in their culturing supernatants. The strain Pediococcus acidilactici 13–7 exhibited potent Cr (VI)-reducing capability and remarkable resistance to Cr (VI) even at concentration as high as 24 mM. Comparative genomics analysis revealed a unique gene, ChrR, associated with Cr (VI) reduction in this strain, distinguishing it from four reference strains of P. acidilactici. The proteomic investigation identified proteins linked to the ChrR gene, such as nqo1, frdA, and gshR, indicating significant enrichment in redox-related functions and oxidative phosphorylation pathways. These findings suggest that P. acidilactici 13–7 possesses superior electron transfer capacity compared to other strains, making it more adaptable under highly oxidative conditions by modulating the external environment to mitigate oxidative stress. Collectively, the results demonstrated the potential application of this lactic acid bacterial strain for bioremediation of heavy metals by its ability to reduce Cr (VI), and shed light on the molecular mechanisms underlying Cr (VI) reduction of the strain P. acidilactici 13–7.

Conversion of notoginsenoside R1 to 3β,12β-dihydroxydammar-(E)-20(22),24-diene-6-O-β-D-xylopyranosyl-(1→2)-β-D-glucopyranoside by Lactiplantibacillus plantarum S165 enhanced protective effects of LPS-induced intestinal epithelial barrier injury in Caco-2 cells.

Microbial transformation to modify saponins and enhance their biological activities has received increasing attention in recent years. This study aimed to screen the strain that can biotransform notoginsenoside R1, identify the product and study its biological activity. A lactic acid bacteria strain S165 with glycosidase-producing activity was isolated from traditional Chinese fermented foods, which was identified and grouped according to API 50 CHL kit and 16S rDNA sequence analysis. Subsequently, notoginsenoside R1 underwent a 30-day fermentation period by the strain S165, and the resulting products were analyzed using High-performance liquid chromatography (HPLC), Ultra-performance liquid chromatography (UPLC)-mass spectrometry (MS)/MS, and 13C-Nuclear magnetic resonance (NMR) techniques. Employing a model of Lipopolysaccharide (LPS)-induced damage to Caco-2 cells, the damage of Caco-2 cells was detected by Hoechst 33 258 staining, and the activity of notoginsenoside R1 biotransformation product was investigated by CCK-8 and western blotting assay. The strain S165 was identified as Lactiplantibacillus plantarum and was used to biotransform notoginsenoside R1. Through a 30-day biotransformation, L. plantarum S165 predominantly converts notoginsenoside R1 into 3β,12β-dihydroxydammar-(E)-20(22),24-diene-6-O-β-D-xylopyranosyl-(1→2)-β-D-glucopyranoside, temporarily named notoginsenoside T6 (NGT6) according to HPLC, UPLC-MS/MS, and 13C-NMR analysis. Results from CCK-8 and Hoechst 33258 staining indicated that the ability notoginsenoside T6 to alleviate the intestinal injury induced by LPS in the Caco-2 cell was stronger than that of notoginsenoside R1. In addition, Western blotting result showed that notoginsenoside T6 could prevent intestinal injury by protecting tight junction proteins (Claudin-1, Occludin, and ZO-1). Notoginsenoside R1 was biotransformed into the notoginsenoside T6 by L. plantarum S165, and the biotransformed product showed an enhanced intestinal protective effect in vitro.

Characterization of Probiotic Potential Lactic Acid Bacteria Isolated from Chinese Cabbage Brassica rapa subsp. Pekinensis

ABSTRACT This study aimed to isolate and evaluate the probiotic potential of lactic acid bacteria (LAB) from Chinese cabbage (Brassica rapa subsp. pekinensis) that is typically used in Kimchi, a Korean fermented product. Lactococcus lactis VLC.1 and VLC.2, and Lactococcus garvieae VLC.3 were identified and further assessed for their probiotic properties. These strains exhibited biological activity such as antioxidant capabilities, antimicrobial activity against pathogenic bacteria, hydrophobicity, and co-aggregation. These findings suggest their potential as probiotics to alleviate oxidative stress and maintain gastrointestinal flora balance. Significantly, the cell-free supernatants derived from LAB isolates exhibited synergistic antimicrobial activity with effectiveness against Escherichia coli, providing novel strategies to address antibiotic resistance challenges. The LAB isolates showed no antibiotic resistance and lacked hemolytic activity, underscoring their safety and efficacy as probiotics. In summary, our findings contribute valuable insights into the biological and safety properties of LAB strains isolated from Chinese cabbage, highlighting their functional benefits.

The isolation and identification of lactic acid bacteria from Indonesian traditional fermented food

Abstract Indigenous Indonesian fermented food is considered a source of probiotics because it usually contains lactic acid bacteria (LAB). Some LAB strains meet the requirement to be probiotics with some functional properties for positive health impacts. However, those functional properties of probiotics have not been fully investigated and need to be continued to complete. To investigate more about LAB from traditional Indonesian fermented foods, the isolation and identification of LAB from some traditional Indonesian fermented foods was done. It was isolated LAB from kimchi (Tangerang), mandai (Banjarmasin), menteng fruit (Banjarmasin), petis (Tangerang and Semarang), salty vegetable (Tangerang), fermented cassava (Tangerang), and fermented durian (Lampung). LAB was isolated in MRS medium with 1% CaCO3, then isolates were characterized biochemically by Gram staining and catalase test. Twenty-one isolates were characterized as gram-positive, and catalase-negative. This strain was further identified by 16S rDNA sequence analysis, the sequences were then checked for similarities using the Basic Local Alignment Search Tool. The result showed that 2 strains of Weissella paramesenteroides found was from Kimci, 1 strain of Pediococcus pentosaceus from mandai, 2 strains of Lactobacillus plantarum from menteng fruit, 1 strain of Leuconostoc pseudomesenteroides from petis Tangerang, 1 strain Bacillus sp from petis Semarang, 1 strain Lactobacillus plantarum from salty vegetable, 2 strain Weissella paramesenteroides from fermented cassava, 4 strain Lactobacillus plantarum and 2 strain Lactobacillus sp from tempoyak.

Plasmid Profile of Lactic Acid Bacteria Isolated from Ogi Encolding for Acetaldehyde in Yoghurt

An investigation was carried out on the plasmid profile of Lactic acid bacteria (LAB) isolated from Ogi samples collected randomly from Bodija market, a local market in Ibadan, Oyo State of Nigeria. Morphological, cultural and physiological characterization was employed to isolate and identify each strain of Lactic acid bacteria (LAB). Lactobacillus spp namely Lactobacillus jensenii, Lactobacillus acidophilus, Lactobacillus bulgaricus, Lactobacillus plantarum, Lactobacillus brevis and Lactobacillus casei were identified. The isolates were inoculated in pasteurized milk to produce Yoghurt (fermented milk product) and were screened for acetaldehyde production using HPLC model Agilent technologies1200. Plasmid profiling of each isolate was done and each isolates harbored plasmid bands. Distinct plasmid bands were seen using the gel electrophoresis of plasmid DNA method. The results shows that acetaldehyde production of the isolates varied from strain to strain and hence could be used as starter culture for yoghurt production with market acceptability.

Screening of Yoghurt Produced by Local Strains of Lactic Acid Bacteria Isolated from Locally Fermented Yoghurt “Kindirmo” For Flavour Compounds

Study’s Novelty/Excerpt This study presents comprehensive screening of local strains of lactic acid bacteria (LAB) isolated from "Kindirmo" for their potential to produce flavor-enhancing compounds in yoghurt. The research uniquely identifies specific LAB strains, such as Leuconostoc mesenteroides dextranicum and Lactobacillus acidophilus, and demonstrates their capacity to produce a variety of volatile flavor compounds using GC–MS analysis. The findings suggest the potential application of these isolates in improving the taste of "Kindirmo" and other food products, thereby contributing valuable insights to the field of food microbiology and fermentation. Full Abstract Yoghurt is known as cultured milk which is derived from the action of bacteria on lactose to produce lactic acid, carbon dioxide (CO2), acetic acid, diacetyl, acetaldehyde, and other flavor compounds. The aim of this research was to screen yoghurt produced by local strains of lactic acid bacteria isolated from locally fermented yoghurt “Kindirmo” for the production of flavor-enhancing compounds. A total of five “Kindirmo” samples were collected from two farmhouses located in Daura local government of Katsina State, Nigeria. The samples were collected and transported in ice containers. Serial dilutions of the “Kindirmo” samples were made and plated using the pour-plate method on de Man, Rogosa, and Sharpe (MRS) agar and incubated anaerobically at 37°C for 72 hours, followed by bacterial identification using Vitek system. Thereafter, yoghurt was produced using the isolated lactic acid bacteria and volatile flavor compounds in the yoghurt were determined using GC–MS analysis. Out of all the five (5) samples analyzed, only two (2) were positive for Lactic acid bacteria. The lactic acid bacteria identified were leuconostoc mesenteroides dextranicum and Lactobacillus acidophilus. While Lactobacillus acidophilus produced 14 volatile flavor compounds, leuconostoc mesenteroides dextranicum produced only 12. Butanoic acid, Hexanoic acid, Acetaldehyde, Propane, Acetone, ethyl ester, Lactic acid, and Diacetone were some of the flavor compounds detected. The research shows the potentials of the isolated LAB to produce flavor compounds, which could be used to enhance the taste of Kindirmo. It is recommended that the isolates should be used for further study on how to produce Kindirmo with single and co-culture of the LAB, or rather on how to produce the flavor enhancers for application in other foods or food products.

Microbial interactions in mixed-species biofilms on the surfaces of Baijiu brewing environments

Environmental microorganisms commonly inhabit dense multispecies biofilms, fostering mutualistic relationships and co-evolution. However, the mechanisms underlying biofilm formation and microbial interactions within the Baijiu fermentation microecosystem remain poorly understood. Hence, the objective of this study was to investigate the composition, structure, and interactions of microorganisms residing in biofilms on environmental surfaces in Baijiu production. The results revealed a shift in the bacteria-fungi interaction network following fermentation, transitioning from a cooperative/symbiotic relationship to a competitive/antagonistic dynamic. Core microbiota within the biofilms comprised lactic acid bacteria (LAB), yeast, and filamentous fungi. From the environmental surface samples, we isolated two strains of LAB (Lactiplantibacillus pentosus EB27 and Pediococcus pentosaceus EB35) and one strain of yeast (Pichia kudriavzevii EF8), all displaying remarkable biofilm formation and fermentation potential. Co-culturing LAB and yeast demonstrated a superior capacity for dual-species biofilm formation compared to mono-species biofilms. The dual-species biofilm displayed a two-layer structure, with LAB in the lower layer and serving as the foundation for the yeast community in the upper layer. The upper layer exhibited a dense distribution of yeast, enhancing aerobic respiration. Metabolic activities in the dual-species biofilm, such as ABC transporter, oxidative phosphorylation, citric acid cycle, sulfur metabolism, glycine, serine, threonine metabolism, lysine degradation, and cysteine and methionine metabolism, showed significant alterations compared to LAB mono-species biofilms. Moreover, bacterial chemotaxis, starch, and sucrose metabolism in the dual-species biofilm exhibited distinct patterns from those observed in the yeast mono-species biofilm. This study demonstrated that a core microbiota with fermentation potential may exist in the form of a biofilm on the surface of a Baijiu brewing environment. These findings provide a novel strategy for employing synthetic stable microbiotas in the intelligent brewing of Baijiu.

Probiogenomic analysis of Lactiplantibacillus plantarum SPS109: A potential GABA-producing and cholesterol-lowering probiotic strain

Lactiplantibacillus plantarum SPS109, an isolated strain of lactic acid bacteria (LAB) from fermented foods, showed remarkable potential as a probiotic with dual capabilities in γ-aminobutyric acid (GABA) production and cholesterol reduction. This study employs genomic and comparative analyses to search into the strain's genetic profile, safety features, and probiotic attributes. The safety assessment reveals the absence of virulence factors and antimicrobial resistance genes, while the genome uncovers bacteriocin-related elements, including sactipeptides and a cluster for putative plantaricins, strengthening its ability to combat diverse pathogens. Pangenome analysis revealed unique bacteriocin-related genes, specifically lcnD and bcrA, distinguishing SPS109 from four other L. plantarum strains producing GABA. In addition, genomic study emphasizes SPS109 strain distinctive features, two GABA-related genes responsible for GABA production and a bile tolerance gene (cbh) crucial for cholesterol reduction. Additionally, the analysis highlights several genes of potential probiotic properties, including stress tolerance, vitamin production, and antioxidant activity. In summary, L. plantarum SPS109 emerges as a promising probiotic candidate with versatile applications in the food and beverage industries, supported by its unique genomic features and safety profile.

Immune Boosting Effect of Limosilactobacillus Reuteri in Immunocompetent C57BL/6J Mice.

Probiotics are well-known to be directly or indirectly involved in the host immune system. In this study, we analyzed the immune-boosting effects of lactic acid bacteria, including Limosilactobacillus and Lactococcus, in immunocompetent C57BL/6J mice. Three different lactic acid bacteria strains were orally administered to C57BL/6J mice for 8 weeks. Then, liver, spleen, and whole blood were harvested after sacrificing the animals. There were no significant changes in whole-body weight, weight of organs, or complete blood cell count by oral administration of lactic acid bacteria. The frequencies of CD3+, CD4+, and CD8+ T cells were significantly increased in the Limosilactobacillus reuteri MG5462 group compared to control. The frequency of NK1.1+ cells was significantly increased in the Lactococcus lactis MG5474 group compared to control. On the other hand, splenocyte proliferations and natural killer cytotoxicity did not differ between groups. In addition, the MG5462 group had a significant increase in the production of TNF-α compared to the control, which is consistent with the upregulation of T cells in the MG5462 group. Therefore, Limosilactobacillus reuteri could be a functional food additive to boost immunity by positively affecting T cell populations.

Development and Evaluation of Bioconverted Milk with Anti-Microbial Effect against Periodontal Pathogens and α-Glucosidase Inhibitory Activity.

To decrease periodontal pathogens and increase the number of beneficial bacteria, probiotics and bioactive compounds made via microbial bioconversion are recently used. In addition, the interest regarding probiotics-mediated bioconversion with popular medicinal plants is increasing. Artemisia herba-alba, a type of wormwood, has recently been attention as a medicinal plant due to its various bioactive compounds. Therefore, we developed bioconverted milk containing A. herba-alba that effectively inhibited periodontal pathogens and α-glucosidase. To select the appropriate lactic acid bacteria for the probiotic candidate strain, 74 strains of lactic acid bacteria were screened. Among them, Lactiplantibacillus plantarum SMFM2016-RK was chosen as the probiotic due to its beneficial characteristics such as high acid and bile tolerance, antioxidant activity, and α-glucosidase inhibition. Based on the minimal bactericidal concentration against three periodontal pathogens, the following appropriate concentrations of Artemisia herba-alba extract were added to milk: 5 mg/mL of A. herba-alba ethanol extract and 25 mg/mL of A. herba-alba hot-water extract. Four bioconverted milks (BM), BM1, BM2, BM3, and BM4, were produced by combining L. plantarum SMFM2016-RK alone, L. plantarum SMFM2016-RK and ethanol extract, L. plantarum SMFM2016-RK and hot-water extract, and L. plantarum SMFM2016-RK with both extracts. As a result of antimicrobial activity, BM3 inhibited the growth of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis the most, and BM4 suppressed the growth of Fusobacterium nucleatum the most. In addition, bioconverted milk containing A. herba-alba (BM2, BM3, and BM4) inhibited α-glucosidase more effectively than BM1. The whole genome of L. plantarum SMFM2016-RK was obtained, and 3135 CDS, 67 tRNA, and 16 RNA were predicted. The genome annotation of L. plantarum SMFM2016-RK revealed 11 CDS related to proteolysis and amino acid metabolism and 2 CDS of phenolic acid-metabolizing enzymes. In conclusion, A. herba-alba-added milk bioconverted by L. plantarum SMFM2016-RK displayed both the growth inhibitory effect on periodontal pathogens and the α-glucosidase inhibitory activity; thus, it necessitates to evaluate the effects on the alleviation of periodontal diseases and glycemic control through future animal experiments.

Differences in the Ability of Lactic Acid Bacteria To Prevent Acute Alcohol-Induced Liver Injury via the Gut Microbiota-Bile Acid-Liver Axis.

Probiotics can regulate gut microbiota and protect against acute alcohol-induced liver injury through the gut-liver axis. However, efficacy is strain-dependent, and their mechanism remains unclear. This study investigated the effect of lactic acid bacteria (LAB), including Lacticaseibacillus paracasei E10 (E10), Lactiplantibacillus plantarum M (M), Lacticaseibacillus rhamnosus LGG (LGG), Lacticaseibacillus paracasei JN-1 (JN-1), and Lacticaseibacillus paracasei JN-8 (JN-8), on the prevention of acute alcoholic liver injury in mice. We found that LAB pretreatment reduced serum alanine transaminase (ALT) and aspartate transaminase (AST) and reduced hepatic total cholesterol (TC) and triglyceride (TG). JN-8 pretreatment exhibited superior efficacy in improving hepatic antioxidation. LGG and JN-8 pretreatment significantly attenuated hepatic and colonic inflammation by decreasing the expression of interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) and increasing the expression of interleukin 10 (IL-10). JN-1 and JN-8 pretreatments have better preventive effects than other LAB pretreatment on intestinal barrier dysfunction. In addition, the LAB pretreatment improved gut microbial dysbiosis and bile acid (BA) metabolic abnormality. All of the strains were confirmed to have bile salt deconjugation capacities in vitro, where M and JN-8 displayed higher activities. This study provides new insights into the prevention and mechanism of LAB strains in preventing acute alcoholic liver injury.

Exopolysaccharide from Lacticaseibacillus paracasei alleviates gastritis in Helicobacter pylori-infected mice by regulating gastric microbiota.

Many probiotics have the ability to produce extracellular polysaccharides (EPS). EPS derived from these probiotics has been confirmed to regulate the host intestinal microecological balance and alleviate the symptoms of diseases caused by gastrointestinal microecological imbalance. Lactic acid bacteria (LAB) strain with good exopolysaccharide (EPS) producing ability, namely, Lacticaseibacillus paracasei ZFM54 (L. paracasei ZFM54) was screened. The fermentation conditions of L. paracasei ZFM54 for EPS production were optimized. The EPS54 was characterized by chemical component and monosaccharide composition determination, UV, FT-IR and NMR spectra analysis. Cango red, SEM, AFM and XRD analysis were conducted to characterize the structure of EPS54. The EPS54 effectively reduced the colonization of Helicobacter pylori to AGS cells and recovered the cell morphology. EPS54 could also effectively alleviate the gastritis in the H. pylori-infected mice by down-regulating the mRNA expression levels of pro-inflammatory cytokines IL-6, IL-8, IL-1β and TNF-α and up-regulating the mRNA expression of inflammatory cytokine IL-10 in gastric cells. EPS54 was also found to be able to positively regulate the structure of gastric microbiota. The EPS 54 from L. paracasei ZFM54 can alleviate gastritis in H. pylori-infected mice by modulating the gastric microbiota.

Dynamic changes in aromas and precursors of edible fungi juice: mixed lactic acid bacteria fermentation enhances flavor characteristics.

Lactic acid bacteria (LAB) fermentation technology has been increasingly used in the deep processing of edible fungi. However, the flavor profiles of edible fungi products after mixed LAB fermentation have received less attention and how aromas changes during the mixed LAB fermentation are still open questions. In the present study, fermented Hericium erinaceus and Tremella fuciformis compound juice (FHTJ) was prepared by mixed LAB strains. We aimed to systematically monitor the dynamic changes of aromas and precursors throughout the fermentation process and a data-driven association network analysis was used to tentatively illustrate the mechanisms of formation between aromas and their precursors. Mixed LAB fermentation could enrich the aroma profile of FHTJ, reducing the unpleasant flavors such as nonanal and 1-octen-3-ol, as well as increasing the floral flavors such as ethyl acetate and α-pinene. Partial least squares-discriminant analysis and relative odor activity values revealed that 11 volatile chemicals were recognized as aroma-active markers. Volcano plot analysis showed that 3-octen-2-one (green flavor) was the key aroma-active marker in each stage, which was down-regulated in fermentation stages I, II and IV, whereas it was up-regulated in stage III. 3-Octen-2-one was significantly negatively correlated with organic acids, particularly pyruvate (r2 = -0.89). Ethyl caprylate (floral flavor) was up-regulated in the late fermentation stage, and showed a negative correlation with sugar alcohols and a positive correlation with organic acids, especially tartaric acid (r2 = 0.96). The present study demonstrates the beneficial effect of mixed LAB fermentation on flavor characteristics, providing guidance for fermented edible fungi juice flavor quality monitoring and control. © 2024 Society of Chemical Industry.

Evaluation of Functional Properties of Some Lactic Acid Bacteria Strains for Probiotic Applications in Apiculture.

This study evaluates the suitability of three lactic acid bacteria (LAB) strains-Lactiplantibacillus plantarum, Lactobacillus acidophilus, and Apilactobacillus kunkeei-for use as probiotics in apiculture. Given the decline in bee populations due to pathogens and environmental stressors, sustainable alternatives to conventional treatments are necessary. This study aimed to assess the potential of these LAB strains in a probiotic formulation for bees through various in vitro tests, including co-culture interactions, biofilm formation, auto-aggregation, antioxidant activity, antimicrobial activity, antibiotic susceptibility, and resistance to high osmotic concentrations. This study aimed to assess both the individual effects of the strains and their combined effects, referred to as the LAB mix. Results indicated no mutual antagonistic activity among the LAB strains, demonstrating their compatibility with multi-strain probiotic formulations. The LAB strains showed significant survival rates under high osmotic stress and simulated gastrointestinal conditions. The LAB mix displayed enhanced biofilm formation, antioxidant activity, and antimicrobial efficacy against different bacterial strains. These findings suggest that a probiotic formulation containing these LAB strains could be used for a probiotic formulation, offering a promising approach to mitigating the negative effects of pathogens. Future research should focus on in vivo studies to validate the efficacy of these probiotic bacteria in improving bee health.

Utjecaj komercijalnih inokulanata na kemijski sastav i fermentaciju silaže od lucerne

Krmne mahunarke teško se siliraju, pa je potrebno primijeniti starter-kulturu od odabranih sojeva bakterija mliječne kiseline koji podupiru proces siliranja i sprječavaju nepoželjne bakterijske maslačne fermentacije te time doprinose očuvanju i poboljšanju kvalitete silaže. Cilj istraživanja bio je procijeniti učinke komercijalnih inokulanata na kemijski sastav i fermentaciju silaže lucerne kultivara OS99. Masa lucerne podijeljena je u šest jednakih dijelova (kontrola – silaža bez inokulanta) i silaža tretirana komercijalnim inokulantima (PIO1 – Pioneer 11H50, PIO2 – Pioneer 11AFT, SIL – Silko, BON – Bonsilage alfa i SAL – Sil–All4 × 4), sve silirano u mikrosilosima. Nakon 90 dana od siliranja, silaže su analizirane s obzirom na kemijski sastav te fermentacijske parametre. Udio suhe tvari i sirovih proteina bio je veći, a udio mliječne i octene kiseline bio je značajno (p<0,05) veći u silaži tretiranoj inokulantima PIO1, PIO2, SIL, BON i SAL u odnosu na kontrolu. Silaža lucerne tretirana inokulantima PIO1, PIO2, SIL, BON i SAL imala je niži udio kiselih i neutralnih deterdžentskih vlakana, niži pH te značajno (p <0,05) niži udio maslačne kiseline, alkohola i NH3–N u usporedbi s kontrolom. Rezultati istraživanja pokazali su da komercijalni inokulanti PIO1, PIO2, SIL, BON i SAL povećavaju kvalitetu silaže lucerne kultivara OS99 u odnosu na kontrolu.

An alginate-based edible coating containing lactic acid bacteria extends the shelf life of fresh strawberry (Fragaria × ananassa Duch.)

Edible coatings, formulated with sodium alginate and various strains of lactic acid bacteria, were evaluated for their effectiveness in extending the shelf life and mitigating microbial risks associated with strawberries. This study specifically employed strains of Lacticaseibacillus paracasei, Lacticaseibacillus rhamnosus, and Lacticaseibacillus plantarum as antimicrobial agents. Through physicochemical property analysis, the alginate-based antimicrobial coating proved most effective in reducing the strawberry weight loss rate, decay index, and ascorbic acid degradation. Over time, all treatments exhibited increased fungal growth. However, strawberries treated with alginate and lactic acid bacteria recorded lower final colony formation counts—6.82 log CFU/g for SA + LPC, 6.04 log CFU/g for SA + LGG, and 6.26 log CFU/g for SA + LP—compared to 8.73 log CFU/g in the control group. In terms of bacterial resistance under gastrointestinal conditions, L. paracasei demonstrated the highest survival rate post-simulated gastric fluid exposure, while L. plantarum showed the greatest resilience post-simulated intestinal fluid exposure. These findings underscore the efficacy of alginate-based antimicrobial coatings in not only enhancing the storage quality of strawberries but also ensuring microbial safety and potential benefits for gut health.

The Effect of Different Medium Compositions and LAB Strains on Fermentation Volatile Organic Compounds (VOCs) Analysed by Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS)

Lactic acid bacteria (LAB) fermentation is a viable approach for producing plant-based flavour compounds; however, little is understood about the impact of different LAB strains and medium compositions on the production of volatile organic compounds (VOCs). This study investigated the impact of the addition of individual amino acids (AAs) (L-leucine, L-isoleucine, L-phenylalanine, L-glutamic acid, L-aspartic acid, L-threonine, or L-methionine) to a defined medium (DM) on the generation of VOCs (after 0, 7, and 14 days) by one of three LAB strains (Levilactobacillus brevis WLP672 (LB672), Lactiplantibacillus plantarum LP100 (LP100), and Pediococcus pentosaceus PP100 (PP100)), using proton transfer reaction-time of flight-mass spectrometry (PTR-ToF-MS). The concentration of m/z 45.031 (t.i. acetaldehyde) was significantly (p < 0.05) higher after 7 days of fermentation by LP100 in the DM supplemented with threonine compared to all other media fermented by all three strains. The concentrations of m/z 49.012 (t.i. methanethiol) and m/z 95.000 (t.i. dimethyl disulfide) were significantly (p < 0.05) higher after 7 days of fermentation by either LP100, PP100, or LB672 in the DM supplemented with methionine compared to all other media. Information on the role of individual AAs on VOCs generation by different LAB strains will help to guide flavour development from the fermentation of plant-based substrates.

MALDI-TOF MS profiling and antifungal activity of lactic acid bacteria from kunu aya, a tiger nut traditional beverage of Nigeria

The application of matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF MS) as a technique for high-throughput characterization of microbiota in African traditional foods is limited. Kunu aya is an unexplored reservoir of protective lactic acid bacteria (LAB) strains. A total of 26 LAB isolates from kunu aya were identified using MALDI-TOF MS as five species, including Lactiplantibacillus plantarum (14), Pediococcus pentosaceus (9), Levilactobacillus brevis (1), Lactiplantibacillus pentosus (1), and Weissella paramesenteroides (1). Antifungal activity screening of all LAB strains by agar-plate overlay assay revealed inhibition against Penicillium crustosum FOO5BA and/or Aspergillus flavus FOO8BA by six strains: L. plantarum (3), Pd. pentosaceus (1), L. brevis (1), and W. paramesenteroides (1). The six LAB strains demonstrated broad spectrum antifungal activity, when tested against eight molds from plant-based foods, inhibiting 4 to 7 molds, with average inhibition scores (AIS) of 0.75–2.75. L. brevis MKAIA1b showed the strongest antifungal activity (AIS; 2.75). Agar diffusion method revealed that antifungal activity against all target molds was retained in cell-free supernatants of L. brevis MKAIA1b, with the highest inhibition demonstrated against P. citrinum 3AS1 (15.34%). In challenged kunu aya fermented with L. brevis MKAIA1b or L. brevis MKAIA1b and L. plantarum TMP051, the growth of A. flavus F008BA, Fusarium langesthiae 13,014, and P. crustosum FOO5BA was delayed beyond 7 days at ambient temperature (25 °C). In this study, MALDI-TOF MS was an effective tool to reveal the species composition of LAB in kunu aya, which harbors LAB strains that displayed strong antifungal activity, while showing great potentials as a protective culture and for bio-control.