Metabolism Characteristics of Lactic Acid Bacteria and the Expanding Applications in Food Industry

Moderate concentration of Lactobacillus metabolites does not adversely affect mouse sperm

Many couples in contemporary societies suffer from infertility of unexplained origins (idiopathic). A promising treatment strategy within this context involves the administration to women of preparations containing lactic acid bacteria (Lactobacillus) and/or their metabolites. Recent investigations underscore the role of lactobacilli in sustaining female fertility and enhancing the effectiveness of assisted reproductive techniques. There have also been reports describing the effect of lactobacilli on sperm functions, but our knowledge in this domain remains uncertain. In this study, the effect of supernatant from Lactobacillus rhamnosus culture on mouse sperm viability and motility was tested. The protective properties of lactobacilli metabolites against hydrogen peroxide-induced DNA damage were also verified. It was shown that the metabolites have no effect on viability, motility, and genome integrity of spermatozoa, but in excessive concentrations they become toxic. The obtained results imply that probiotic and/or postbiotic preparations taken by women should not adversely affect the sperm of their partners, provided the dose is correctly selected.

Exploring the flavor changes in mung bean flour through Lactobacillus fermentation: insights from volatile compounds and non-targeted metabolomics analysis

BACKGROUND

Mung beans are highly nutritious but their leguminous flavor limits their development. Lactic acid bacteria (LAB) fermentation can decrease unwanted bean flavors in legumes and enhance their flavor. This study examined the influence of Lactobacillus fermentation on the flavor characteristics of mung bean flour (MBF) using volatile compounds and non-targeted metabolomics.

RESULTS

Lactobacillus plantarum LP90, Lactobacillus casei LC89, and Lactobacillus acidophilus LA85 eliminated 61.37%, 48.29%, and 43.73%, respectively, of the primary bean odor aldehydes from MBF. The relative odor activity value (ROAV) results showed that fermented mung bean flour (FMBF) included volatile chemicals that contributed to fruity, flowery, and milky aromas. These compounds included ethyl acetate, hexyl formate, 3-hydroxy-2-butanone, and 2,3-butanedione. The levels of amino acids with a fresh sweet flavor increased significantly by 93.89, 49.40, and 35.27% in LP90, LC89, and LA85, respectively. A total of 49 up-regulated and 13 down-regulated significantly differential metabolites were annotated, and ten metabolic pathways were screened for contributing to the flavor. The correlation between important volatile compounds and non-volatile substances relies on two primary metabolic pathways: the citric acid cycle pathway and the amino acid metabolic system.

CONCLUSION

The flavor of MBF was enhanced strongly by the process of Lactobacillus fermentation, with LP90 having the most notable impact. These results serve as a reference for identifying the flavor of FMBF. © 2024 Society of Chemical Industry.

The occurrence, role, and management strategies for phytic acid in foods

Phytic acid, a naturally occurring compound predominantly found in cereals and legumes, is the focus of this review. This review investigates its distribution across various food sources, elucidating its dual roles in foods. It also provides new insights into the change in phytic acid level during food storage and the evolving trends in phytic acid management. Although phytic acid can function as a potent color stabilizer, flavor enhancer, and preservative, its antinutritional effects in foods restrict its applications. In terms of management strategies, numerous treatments for degrading phytic acid have been reported, each with varying degradation efficacies and distinct mechanisms of action. These treatments encompass traditional methods, biological approaches, and emerging technologies. Traditional processing techniques such as soaking, milling, dehulling, heating, and germination appear to effectively reduce phytic acid levels in processed foods. Additionally, fermentation and phytase hydrolysis demonstrated significant potential for managing phytic acid in food processing. In the future, genetic modification, due to its high efficiency and minimal environmental impact, should be prioritized to downregulate the biosynthesis of phytic acid. The review also delves into the biosynthesis and metabolism of phytic acid and elaborates on the mitigation mechanism of phytic acid using biotechnology. The challenges in the application of phytic acid in the food industry were also discussed. This study contributes to a better understanding of the roles phytic acid plays in food and the sustainability and safety of the food industry.

Serial fermentation in milk generates functionally diverse community lineages with different degrees of structure stabilization

Microbial communities offer considerable potential for tackling environmental challenges by improving the functioning of ecosystems. Top-down community engineering is a promising strategy that could be used to obtain communities of desired function. However, the ecological factors that control the balance between community shaping and propagation are not well understood. Dairy backslopping, which consists of using part of the previous production to inoculate a new one, can be used as a model engineering approach to investigate community dynamics during serial propagations. In this study, 26 raw milk samples were serially propagated 6 times each, giving rise to 26 community lineages. Bacterial community structures were analyzed by metabarcoding, and acidification was recorded by pH monitoring. The results revealed that different types of community lineages could be obtained in terms of taxonomic composition and dynamics. Five lineages reached a repeatable community structure in a few propagation steps, with little variation between the final generations, giving rise to stable acidification kinetics. Moreover, these stabilized communities presented a high variability of structure and diverse acidification properties between community lineages. Besides, the other lineages were characterized by different levels of dynamics leading to parallel or divergent trajectories. The functional properties and dynamics of the communities were mainly related to the relative abundance and the taxonomic composition of lactic acid bacteria within the communities. These findings highlight that short-term schemes of serial fermentation can produce communities with a wide range of dynamics and that the balance between community shaping and propagation is intimately linked to community structure.

IMPORTANCE

Microbiome applications require approaches for shaping and propagating microbial communities. Shaping allows the selection of communities with desired taxonomic and functional properties, while propagation allows the production of the biomass required to inoculate the engineered communities in the target ecosystem. In top-down community engineering, where communities are obtained from a pool of mixed microorganisms by acting on environmental variables, a major challenge is to master the balance between shaping and propagation. However, the ecological factors that favor high dynamics of community structure and, conversely, those that favor stability during propagation are not well understood. In this work, short-term dairy backslopping was used to investigate the key role of the taxonomic composition and structure of bacterial communities on their dynamics. The results obtained open up interesting prospects for the biotechnological use of microbiomes, particularly in the field of dairy fermentation, to diversify approaches for injecting microbial biodiversity into cheesemaking processes.

Experimental evolution of gene essentiality in bacteria

Essential gene products carry out fundamental cellular activities in interaction with other components. However, the lack of essential gene mutants and appropriate methodologies to link essential gene functions with their partners poses significant challenges. Here, we have generated deletion mutants in 32 genes previously identified as essential, with 23 mutants showing extremely slow growth in the SK36 strain of Streptococcus sanguinis . Whole-genome sequencing of 243 independently evolved populations of these mutants has identified >1000 spontaneous suppressor mutations in experimental evolution, many of which define new gene and pathway relationships, such as F1Fo-ATPase/V1Vo-ATPase/TrkA1-H1. Patterns of spontaneous mutations occurring in essential gene mutants differed from those found in wildtype. While gene duplications occurred rarely and appeared most often at later stages of evolution, substitutions, deletions, and insertions were prevalent in evolved populations. These essential gene deletion mutants and spontaneous mutations fixed in the mutant populations during evolution establish a foundation for understanding gene essentiality and the interaction of essential genes in networks.

In vitro digestive system simulation and anticancer activity of soymilk fermented by probiotics and synbiotics immobilised on agro-industrial residues

In this study, a variety of probiotic strains, including Lactiplantibacillus plantarum, Lacticaseibacillus casei, Lactobacillus acidophilus, Streptococcus thermophilus, Bifidobacterium longum, Limosilactobacillus reuteri, Lactobacillus delbrueckii subsp. bulgaricus, Lacticaseibacillus rhamnosus, and Bifidobacterium bifidum, were utilized for soymilk fermentation both as free cells and as synbiotics on agro-industrial residuals such as okara, whey protein, banana peels, apple pomace, sugarcane bagasse, orange peels, and lemon peels. Among these, Lacticaseibacillus rhamnosus emerged as the most significant strain for soymilk fermentation, exhibiting a viability of 10.47 log cfu/mL, a pH of 4.41, total acidity of 1.12%, and organic acid contents (lactic and acetic acid) of 11.20 and 7.50 g/L, respectively. As a synbiotic Lacticaseibacillus rhamnosus immobilised on okara, showed even more impressive results, with a viability of 12.98 log cfu/mL, a pH of 4.31, total acidity of 1.27%, and organic acid contents of 13.90 and 9.30 g/L, respectively. Over a 12-h fermentation period, cell viability values increased by 10.47-fold in free cells and 11.19-fold in synbiotics. Synbiotic supplementation of fermented soymilk proved more beneficial than free cells in terms of viability, acidity, and organic acid content. Furthermore, when synbiotic fermented soymilk was freeze-dried to simulate the digestive system in vitro, synbiotics and freeze-dried cells demonstrated superior gastrointestinal tract survival compared to free cells. Both the probiotic bacteria and the synbiotics exhibited cytotoxicity against colon and liver cancer cell lines, with half-maximal inhibitory concentrations ranging from 41.96 to 61.52 μL/well.

Multidisciplinary advances in kombucha fermentation, health efficacy, and market evolution

Kombucha, a fermented tea beverage, has seen a significant rise in global popularity. This increase is attributed to its reported health benefits and extensive cultural heritage. The comprehensive review examines kombucha through microbiology, biochemistry, and health sciences, highlighting its therapeutic potential and commercial viability. Central to kombucha production is the symbiotic culture of bacteria and yeasts (SCOBY), which regulates a complex fermentation process, resulting in a bioactive-rich elixir. The study examines the microbial dynamics of SCOBY, emphasizing the roles of various microorganisms. It focuses the contributions of acetic acid bacteria, lactic acid bacteria, and osmophilic yeasts, including genera such as Saccharomyces, Schizosaccharomyces, Zygosaccharomyces, Brettanomyces/Dekkera, and Pichia. These microorganisms play crucial roles in producing bioactive compounds, including organic acids, polyphenols, and vitamins. These bioactive compounds confer therapeutic properties to kombucha. These properties include antioxidant, antimicrobial, anti-inflammatory, antidiabetic, antihypertensive, cancer prevention, hepatoprotective, and detoxifying effects. The review also explores the growing market for kombucha, driven by consumer demand for functional beverages and opportunities for innovative product development. It emphasizes the necessity of standardized production to ensure safety and validate health claims. Identifying research gaps, the review highlights the importance of clinical trials to verify therapeutic benefits. Ultimately, this study integrates traditional knowledge with scientific research, providing directions for future studies and commercial expansion, emphasizing the role of kombucha in health and wellness.

Overview of cloning in lactic acid bacteria: Expression and its application of probiotic potential in inflammatory bowel diseases

Inflammatory bowel disease (IBD) imposes a significant impact on the quality of life for affected individuals. However, there was a current lack of a systematic summary regarding the latest epidemic trends and the underlying pathogenesis of IBD. This highlights the need for a thorough examination of both the epidemiological aspects of IBD and the specific mechanisms by which lactic acid bacteria (LAB) contribute to mitigating this condition. In developed countries, higher incidences and death rates of IBD have been observed, influenced by a combination of environmental and genetic factors. LAB offer significant advantages and substantial potential for enhancing IBD treatment. LAB's capabilities include the production of bioactive metabolites, regulation of gut immunity, protection of intestinal mechanical barriers, inhibition of oxidative damage, and restoration of imbalanced gut microbiota. The review suggests that screening effective LAB using cell models and metabolites, optimizing LAB intake through dose-effect studies, enhancing utilization through nanoencapsulation and microencapsulation, investigating mechanisms to deepen the understanding of LAB, and refining clinical study designs. These efforts aim to contribute to comprehending the epidemic trend, pathogenesis, and treatment of IBD, ultimately fostering the development of targeted therapeutic products, such as LAB-based interventions.

Probiotic Functions in Fermented Foods: Anti-Viral, Immunomodulatory, and Anti-Cancer Benefits

Fermented foods can provide many benefits to our health. These foods are created by the action of microorganisms and help support our digestive health and immune system. Fermented foods include yogurt, kimchi, pickles, kefir, beer, wine, and more. Fermented foods contain probiotics, lactic acid bacteria (LAB), yeast, organic acids, ethanol, or antimicrobial compounds, which help balance the gut microbiome and improve digestive health. Fermented foods can also benefit your overall health by increasing the diversity of your gut microbiome and reducing inflammation. By routinely consuming fermented foods with these benefits, we can continue to improve our health. Probiotics from fermented foods are beneficial strains of bacteria that are safe for human health and constitute an important component of human health, even for children and the elderly. Probiotics can have a positive impact on your health, especially by helping to balance your gut microbiome and improve digestive health. Probiotics can also boost your immune system and reduce inflammation, which can benefit your overall health. Probiotics, which can be consumed in the diet or in supplement form, are found in many different types of foods and beverages. Research is continuing to investigate the health effects of probiotics and how they can be utilized. The potential mechanisms of probiotics include anti-cancer activity, preventing and treating immune system-related diseases, and slowing the development of Alzheimer's disease and Huntington's disease. This is due to the gut-brain axis of probiotics, which provides a range of health benefits beyond the digestive and gastrointestinal systems. Probiotics reduce tumor necrosis factor-α and interleukins through the nuclear factor-kappa B and mitogen-activated protein kinase pathways. They have been shown to protect against colon cancer and colitis by interfering with the adhesion of harmful bacteria in the gut. This article is based on clinical and review studies identified in the electronic databases PubMed, Web of Science, Embase, and Google Scholar, and a systematic review of clinical studies was performed.

Postbiotics as Adjuvant Therapy in Cancer Care

Postbiotics are defined as a preparation of inanimate microorganisms and/or their components that confers a health benefit to the host. They range from cell wall fragments to metabolites, bacterial lysates, extracellular vesicles, and short-chain fatty acids (SCFAs). Postbiotics may influence carcinogenesis via a variety of mechanisms. They can promote homeostatic immune responses, reduce inflammation, induce selective cytotoxicity against tumor cells, as well as the enabling the control of tumor cell proliferation and enhancing intestinal epithelial barrier function. Therefore, probiotics can serve as an adjunct strategy in anticancer treatment together with chemotherapy and immunotherapy. Up to now, the only relevant postbiotics used as interventions in oncological patients remain vitamin K molecules, with few phase-II and III trials available. In fact, postbiotics' levels are strictly dependent on the gut microbiota's composition, which may vary between individuals and can be altered under different physiological and pathological conditions. Therefore, the lack of consistent clinical evidence supporting postbiotics' efficacy is due to their poor bioavailability, short half-life, and fluctuating levels. Synbiotics, a mixture of prebiotics and probiotics, are expected to have a more homogeneous bioavailability with respect to postbiotics and may have greater potential for future development. In this review, we focus on the role of postbiotics as an adjuvant therapy in cancer treatment.

Probiotic Potential of Lactobacillus and Enterococcus Strains Isolated From the Faecal Microbiota of Critically Endangered Hangul Deer (Cervus hanglu hanglu): Implications for Conservation Management

The mammalian gut microbiota plays a crucial role in promoting host health, and lactic acid bacteria (LAB) are commonly employed as probiotics for their beneficial effects. The Hangul deer (Cervus hanglu hanglu), a critically endangered red deer subspecies found in the Indian subcontinent, requires meticulous health management for its conservation. This pioneering study aimed to isolate, identify, and evaluate the in-vitro probiotic functional properties of LAB strains from the faeces of Hangul deer. A total of 27 LAB strains were isolated and identified using 16S rDNA gene sequencing, followed by comprehensive probiotic characterization and safety assessment. Remarkably, four species exhibited robust resistance and survivability against varying pH levels and bile salts, along with high aggregation and co-aggregation capacities. Notably, Lactobacillus acidophilus and Enterococcus mundtii strains displayed antibacterial activities. Safety assessment revealed the absence of hemolytic activity and virulence genes in all four strains. Antibiotic susceptibility testing showed that Lactobacillus acidophilus and Enterococcus casseliflavus were susceptible to all tested antibiotics, while Enterococcus mundtii exhibited resistance to clindamycin, and Enterococcus gallinarum exhibited resistance to erythromycin. These findings suggest that the isolated LAB strains possess advantageous probiotic characteristics and hold potential as dietary supplements for promoting the health and disease management of Hangul deer.

Plant species influences the composition of root system microbiome and its antibiotic resistance profile in a constructed wetland receiving primary treated wastewater

Introduction

Constructed wetlands (CWs) are nature-based solutions for wastewater treatment where the root system microbiome plays a key role in terms of nutrient and pollutant removal. Nonetheless, little is known on plant-microbe interactions and bacterial population selection in CWs, which are mostly characterized in terms of engineering aspects.

Methods

Here, cultivation-independent and cultivation-based analyses were applied to study the bacterial communities associated to the root systems of Phragmites australis and Typha domingensis co-occurring in the same cell of a CW receiving primary treated wastewaters.

Results and discussion

Two endophytic bacteria collections (n = 156) were established aiming to find novel strains for microbial-assisted phytodepuration, however basing on their taxonomy the possible use of these strains was limited by their low degrading potential and/or for risks related to the One-Health concept. A sharp differentiation arose between the P. australis and T. domingensis collections, mainly represented by lactic acid bacteria (98%) and Enterobacteriaceae (69%), respectively. Hence, 16S rRNA amplicon sequencing was used to disentangle the microbiome composition in the root system fractions collected at increasing distance from the root surface. Both the fraction type and the plant species were recognized as drivers of the bacterial community structure. Moreover, differential abundance analysis revealed that, in all fractions, several bacteria families were significantly and differentially enriched in P. australis or in T. domingensis. CWs have been also reported as interesting options for the removal of emerging contaminants (e.g, antibiotic resistance genes, ARGs). In this study, ARGs were mostly present in the rhizosphere of both plant species, compared to the other analyzed fractions. Notably, qPCR data showed that ARGs (i.e., ermB, bla TEM, tetA) and intl1 gene (integrase gene of the class 1 integrons) were significantly higher in Phragmites than Typha rhizospheres, suggesting that macrophyte species growing in CWs can display a different ability to remove ARGs from wastewater. Overall, the results suggest the importance to consider the plant-microbiome interactions, besides engineering aspects, to select the most suitable species when designing phytodepuration systems.

Bioactive Hydrogel Formulation Based on Ferulic Acid-Grafted Nano-Chitosan and Bacterial Nanocellulose Enriched with Selenium Nanoparticles from Kombucha Fermentation

Selenium nanoparticles (SeNPs) have specific properties that result from their biosynthesis particularities. Chitosan can prevent pathogenic biofilm development. A wide palette of bacterial nanocellulose (BNC) biological and physical-chemical properties are known. The aim of this study was to develop a hydrogel formulation (SeBNCSFa) based on ferulic acid-grafted chitosan and bacterial nanocellulose (BNC) enriched with SeNPs from Kombucha fermentation (SeNPsK), which could be used as an adjuvant for oral implant integration and other applications. The grafted chitosan and SeBNCSFa were characterized by biochemical and physical-chemical methods. The cell viability and proliferation of HGF-1 gingival fibroblasts were investigated, as well as their in vitro antioxidant activity. The inflammatory response was determined by enzyme-linked immunosorbent assay (ELISA) of the proinflammatory mediators (IL-6, TNF-α, and IL-1β) in cell culture medium. Likewise, the amount of nitric oxide released was measured by the Griess reaction. The antimicrobial activity was also investigated. The grafting degree with ferulic acid was approximately 1.780 ± 0.07% of the total chitosan monomeric units, assuming single-site grafting per monomer. Fourier-transform infrared spectroscopy evidenced a convolution of BNC and grafted chitosan spectra, and X-ray diffraction analysis highlighted an amorphous rearrangement of the diffraction patterns, suggesting multiple interactions. The hydrogel showed a high degree of cytocompatibility, and enhanced antioxidant, anti-inflammatory, and antimicrobial potentials.

The Metabolism of Leuconostoc Genus Decoded by Comparative Genomics

Leuconostoc encompasses a number of species that frequently appear in foods where they play different roles, ranging from ripening to spoiling. The number of available Leuconostoc genomes has recently increased and enabled the precise taxonomic and phylogenetic delineation of species. Nonetheless, a thorough investigation of the functions and the metabolic potential of Leuconostoc species has never been accomplished. In this study, all the currently available 553 Leuconostoc genomes were downloaded from NCBI GenBank and annotated utilizing specific tools in order to reconstruct the metabolic potential of the genus in terms of carbohydrate hydrolysis and fermentative pathways, transporters, and anabolic potential. The analysis revealed that species cluster based on their metabolic potential, showing unique adaptation and ecological roles. Pentose phosphate and phosphoketolase pathways were highlighted as the main ones of central metabolism. The various identified PTS and ABC transporters showed adaptability to different sugars. The metabolic diversity described in this study not only supports the role of Leuconostoc spp. in natural ecosystems but also highlights their potential in industrial applications, particularly in the fermentation industry where their ability to metabolize a wide range of substrates can be harnessed for the production of various fermented foods and bioproducts.

Tracking Metabolite Variations during the Degradation of Vegetables in Rice Bran Bed with Intact-State Nuclear Magnetic Resonance Spectroscopy

Fermentation-a process of compound degradation by microorganisms-is a traditional food processing method utilized worldwide for the long-term preservation of fresh foods. In recent years, fermented foods have gained attention as health foods. Fermentation increases the nutritional value of ingredients, producing complex flavors and aromas. To identify unknown components in fermented foods, it is necessary to analyze compounds and conditions nondestructively and comprehensively. We performed intact-state nuclear magnetic resonance (NMR) spectroscopy using intermolecular single quantum coherence (iSQC) to detect the degradation of vegetables directly and nondestructively. We used two types of vegetables and a rice bran bed (nukazuke), which is used for traditional vegetable fermentation in Japan. Major metabolites such as saccharides, organic acids, and amino acids were identified in iSQC-sliced spectra. Comparing NMR signal intensities during degradation revealed the transition of metabolites characteristic of lactic acid fermentation. A pathway-based network analysis showed pathways involved in amino acid metabolism and lactic acid fermentation. Our analytical approach with intact-state NMR spectroscopy using iSQC demonstrated that it may be effective in other experimental systems, allowing for the evaluation of phenomena that have been conventionally overlooked in their true state.

Staphylococcus aureus in Dairy Industry: Enterotoxin Production, Biofilm Formation, and Use of Lactic Acid Bacteria for Its Biocontrol

Staphylococcus aureus is a well-known pathogen capable of producing enterotoxins during bacterial growth in contaminated food, and the ingestion of such preformed toxins is one of the major causes of food poisoning around the world. Nowadays 33 staphylococcal enterotoxins (SEs) and SE-like toxins have been described, but nearly 95% of confirmed foodborne outbreaks are attributed to classical enterotoxins SEA, SEB, SEC, SED, and SEE. The natural habitat of S. aureus includes the skin and mucous membranes of both humans and animals, allowing the contamination of milk, its derivatives, and the processing facilities. S. aureus is well known for the ability to form biofilms in food processing environments, which contributes to its persistence and cross-contamination in food. The biocontrol of S. aureus in foods by lactic acid bacteria (LAB) and their bacteriocins has been studied for many years. Recently, LAB and their metabolites have also been explored for controlling S. aureus biofilms. LAB are used in fermented foods since in ancient times and nowadays characterized strains (or their purified bacteriocin) can be intentionally added to prolong food shelf-life and to control the growth of potentially pathogenic bacteria. Regarding the use of these microorganism and their metabolites (such as organic acids and bacteriocins) to prevent biofilm development or for biofilm removal, it is possible to conclude that a complex network behind the antagonistic activity remains poorly understood at the molecular level. The use of approaches that allow the characterization of these interactions is necessary to enhance our understanding of the mechanisms that govern the inhibitory activity of LAB against S. aureus biofilms in food processing environments.

Mining the Biosynthetic Landscape of Lactic Acid Bacteria Unearths a New Family of RiPPs Assembled by a Novel Type of ThiF-like Adenylyltransferases

Ribosomally synthesized and post-translationally modified peptides (RiPPs) are chemically diverse natural products of ribosomal origin. These peptides, which frequently act as signals or antimicrobials, are biosynthesized by conserved enzymatic machinery, making genome mining a powerful strategy for unearthing previously uncharacterized members of their class. Herein, we investigate the untapped biosynthetic potential of Lactobacillales (i.e., lactic acid bacteria), an order of Gram-positive bacteria closely associated with human life, including pathogenic species and industrially relevant fermenters of dairy products. Through genome mining methods, we systematically explored the distribution and diversity of ThiF-like adenylyltransferase-utilizing RiPP systems in lactic acid bacteria and identified a number of unprecedented biosynthetic gene clusters. In one of these clusters, we found a previously undescribed group of macrocyclic imide biosynthetic pathways containing multiple transporters that may be involved in a potential quorum sensing (QS) system. Through in vitro assays, we determined that one such adenylyltransferase specifically catalyzes the intracyclization of its precursor peptide through macrocyclic imide formation. Incubating the enzyme with various primary amines revealed that it could effectively amidate the C-terminus of the precursor peptide. This new transformation adds to the growing list of Nature's peptide macrocyclization strategies and expands the impressive catalytic repertoire of the adenylyltransferase family. The diverse RiPP systems identified herein represent a vast, unexploited landscape for the discovery of a novel class of natural products and QS systems.

Fermentation of DaiDai fruit and its biological activity

DaiDai fruit, a medicinal and edible plant fruit, is abundant in biologically active compounds and has a long history of use in traditional Chinese medicine. This research focuses on utilizing fermentation to develop a functional DaiDai fruit fermentation broth. Lactobacillus, Bacillus subtilis and Saccharomyces cerevisiae were employed in the fermentation process. By conducting screenings of bacterial strains, single factor experiments, and response surface methodology, the total flavonoids, polysaccharides, polyphenols, and 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) free radical scavenging rate were used as the index for selection, ultimately identifying Lactobacillus L-13 as the optimal fermentation strain. The optimal fermentation conditions were determined to be a time of 108 h, a temperature of 43.6°C, and a solid-liquid ratio of 1:15.157 (w/v). Under these conditions, the total flavonoid content reached 412.01 mg/g, representing a 36.71% increase compared to conventional extraction methods. The contents of polysaccharides and polyphenols and the DPPH scavenging rate were also increased. The fermentation broth of DaiDai fruit exhibited inhibitory effects on tyrosinase and melanin production in mouse melanoma cells B16-F10 induced by α-MSH and anti-inflammatory properties in a zebrafish inflammation model. These indicate that the DaiDai fruit fermentation broth possesses anti-melanoma, whitening, and anti-inflammatory properties, showcasing significant potential for applications in medicine, cosmetics, and other industries.

Modulating Whey Proteins Antigenicity with Lactobacillus delbrueckii subsp. bulgaricus DLPU F-36 Metabolites: Insights from Spectroscopic and Molecular Docking Studies

Numerous studies have highlighted the potential of Lactic acid bacteria (LAB) fermentation of whey proteins for alleviating allergies. Nonetheless, the impact of LAB-derived metabolites on whey proteins antigenicity during fermentation remains uncertain. Our objective was to elucidate the impact of small molecular metabolites on the antigenicity of α-lactalbumin (α-LA) and β-lactoglobulin (β-LG). Through metabolomic analysis, we picked 13 bioactive small molecule metabolites from Lactobacillus delbrueckii subsp. bulgaricus DLPU F-36 for coincubation with α-LA and β-LG, respectively. The outcomes revealed that valine, arginine, benzoic acid, 2-keto butyric acid, and glutaric acid significantly diminished the sensitization potential of α-LA and β-LG, respectively. Moreover, chromatographic analyses unveiled the varying influence of small molecular metabolites on the structure of α-LA and β-LG, respectively. Notably, molecular docking underscored that the primary active sites of α-LA and β-LG involved in protein binding to IgE antibodies aligned with the interaction sites of small molecular metabolites. In essence, LAB-produced metabolites wield a substantial influence on the antigenic properties of whey proteins.

Microbial Population and Physicochemical Properties of Miang Fermented in Bamboo Tubes by the Luar Ethnic Group in Lao PDR

Miang is a traditional fermented food made from Assam tea leaves and consumed as a snack. This study investigated the underground Miang fermentation process practiced by the Luar ethnic group in Laos, specifically examining the nutritional composition and microbial dynamics. Lactic acid bacteria and yeast were dominant in the fermentation process, reaching 8.43 and 8.50 log CFU/g after one week before gradually declining, while the coliform bacterial count was at 5.31 log CFU/g in the initial week but became undetectable in the later stages of fermentation. Next-generation sequencing identified Firmicutes (75.02%) and Proteobacteria (23.51%) as the primary phyla. Bacterial genera included Lactobacillus (73.36%) and Acetobacter (21.06%), with fungi mainly represented by Pichia (85.52%) and Candida (13.45%). Fundamental microbes such as Lactobacillus and Acetobacter were predominantly present, alongside Pichia and Candida, in the fungal communities. Microbial activities played a crucial role in generating essential enzymes for Miang's transformation. The nutritional transformation appears to be complete at 5 weeks of fermentation. The moisture content in the final products was approximately 74% and correlated with a change in nitrogen-free extract (NFE) and crude fiber. The fat content showed a slight increase from 1.3% to 2.52%, but protein content slightly declined from 17.21% to 16.05%, whereas ash content did not change significantly. Key polysaccharide-degrading enzymes, particularly pectinase and β-mannanase, were revealed and peaked at 48.32 and 25.32 U/g Miang, respectively. The total polyphenols increased from 103.54 mg/g dry Miang to 144.19-155.52 mg/g during fermentation. The lowered IC50 value indicated an increase in antioxidant activity. A fermentation period of at least 3 weeks proved to be optimal for enhancing antioxidant properties and bioactive compounds, and mitigating the risk of coliform bacteria.

Korean urobiome platform (KUROM) study for acute uncomplicated sporadic versus recurrent cystitis in women: Clinical significance

PURPOSE

To investigate urine microbiome differences among healthy women, women with recurrent uncomplicated cystitis (rUC), and those with sporadic/single uncomplicated cystitis (sUC) to challenge traditional beliefs about origins of these infections.

MATERIALS AND METHODS

Patients who underwent both conventional urine culture and next-generation sequencing (NGS) of urine were retrospectively reviewed. Symptom-free women with normal urinalysis results as a control group were also studied. Samples were collected via transurethral catheterization.

RESULTS

In the control group, urine microbiome was detected on NGS in 83.3%, with Lactobacillus and Prevotella being the most abundant genera. The sensitivity of urine NGS was significantly higher than that of conventional urine culture in both the sUC group (91.2% vs. 32.4%) and the rUC group (82.4% vs. 16.4%). In urine NGS results, Enterobacterales, Prevotella, and Escherichia/Shigella were additionally found in the sUC group, while the recurrent urinary tract infection (rUTI)/rUC group exhibited the presence of Lactobacillus, Prevotella, Enterobacterales, Escherichia/Shigella, and Propionibacterium. Moreover, distinct patterns of urine NGS were observed based on menopausal status and ingestion of antibiotics or probiotics prior to NGS test sampling.

CONCLUSIONS

Urine microbiomes in control, sUC, and rUTI/rUC groups exhibited distinct characteristics. Notably, sUC and rUC might represent entirely separate pathological processes, given their distinct urine microbiomes. Consequently, the use of urine NGS might be essential to enhancing sensitivity compared to conventional urine culture in both sUC and rUTI/rUC groups.

Understanding the nutritional benefits through plant proteins-probiotics interactions: mechanisms, challenges, and perspectives

The nutritional benefits of combining probiotics with plant proteins have sparked increasing research interest and drawn significant attention. The interactions between plant proteins and probiotics demonstrate substantial potential for enhancing the functionality of plant proteins. Fermented plant protein foods offer a unique blend of bioactive components and beneficial microorganisms that can enhance gut health and combat chronic diseases. Utilizing various probiotic strains and plant protein sources opens doors to develop innovative probiotic products with enhanced functionalities. Nonetheless, the mechanisms and synergistic effects of these interactions remain not fully understood. This review aims to delve into the roles of promoting health through the intricate interplay of plant proteins and probiotics. The regulatory mechanisms have been elucidated to showcase the synergistic effects, accompanied by a discussion on the challenges and future research prospects. It is essential to recognize that the interactions between plant proteins and probiotics encompass multiple mechanisms, highlighting the need for further research to address challenges in achieving a comprehensive understanding of these mechanisms and their associated health benefits.

Harnessing Bacillus amyloliquefaciens for Amazake Production: Comparison with Aspergillus oryzae Amazake for Metabolomic Characteristics, Microbial Diversity, and Sensory Profile

Amazake is a traditional, sweet, non-alcoholic Japanese beverage typically produced through koji fermentation by the fungus Aspergillus oryzae. However, alternative microorganisms such as Bacillus amyloliquefaciens offer potential advantages and novel possibilities for producing similar fermented beverages. This study aimed to replicate the ancestral beverage of amazake by replacing A. oryzae (W-20) with B. amyloliquefaciens (NCIMB 12077) and comparing their fermentation processes and resulting products. Our results show that the production of amazake with B. amyloliquefaciens (ABA) is not only possible but also results in a beverage that is otherwise distinct from traditional amazake (AAO). Saccharification was achievable in ABA at higher temperatures than in AAO, albeit with lower reducing sugar and enzymatic activity values. Amino acids and organic acids were more abundant in AAO, with cysteine being uniquely present in AAO and shikimic acid only being present in ABA. The volatile aroma compound profiles differed between the two beverages, with AAO exhibiting a greater abundance of aldehydes, and ABA a greater abundance of ketones and alcohols. Interestingly, despite these compositional differences, the two beverages showed similar consumer panel acceptance rates. An analysis of their microbial communities revealed pronounced differences between the amazakes, as well as temporal changes in ABA but not in AAO. This study provides promising insights into harnessing the potential of B. amyloliquefaciens as the primary microorganism in the fermentation process of amazake-like beverages, marking an important advancement in the field of fermented low-alcohol beverage production, with possible applications in other fermented foods.

Biotechnological lactic acid production from low-cost renewable sources via anaerobic microbial processes

Lactic acid (LA) production from microbial fermentation using low-cost renewable sources has emerged as an attractive alternative to the use of petroleum-based products. This approach not only offers sustainable solutions for waste management but also enables the production of value-added products in an eco-friendly manner. However, to make this approach economically viable, optimizing the production process for high yield, productivity, and purity while minimizing costs is crucial. To address these challenges, various approaches have been proposed, including the use of neutralizing agents, high cell density cultures, co-cultures, fed-batch fermentation, and product removal strategies. Overall, this review underscores the potential of microbial fermentation for LA production as a sustainable and cost-effective solution to meet the growing demand for eco-friendly products. Further optimization of fermentation processes and the development of new microbial strains and fermentation techniques are key to advancing this approach. The production of LA through microbial fermentation presents a sustainable and eco-friendly solution to the increasing demand for eco-friendly products. With continued innovation, we can expect to see a significant reduction in the environmental impact of industrial processes, coupled with a more cost-effective and high-purity source of lactic acid for various industries.

Nanopore Identification of L-, D-Lactic Acids, D-Glucose and Gluconic Acid in the Serum of Human and Animals

DL-Lactic acid and D-glucose are important human health indicators. Their aberrant levels in body fluids may indicate a variety of human pathological conditions, suggesting an urgent need of daily monitoring. However, simultaneous and rapid analysis of DL-lactic acid and D-glucose using a sole but simple sensing system has never been reported. Here, an engineered Mycobacterium smegmatis porin A (MspA) nanopore is used to simultaneously identify DL-lactic acid and D-glucose. Highly distinguishable nanopore event features are reported. Assisted with a custom machine learning algorithm, direct identification of DL-lactic acid and D-glucose is performed with human serum, demonstrating its sensing reliability against complex and heterogeneous samples. This sensing strategy is further applied in the analysis of different animal serum samples, according to which gluconic acid is further identified. The serum samples from different animals report distinguishable levels of DL-lactic acid, D-glucose and gluconic acid, suggesting its potential applications in agricultural science and breeding industry. This sensing strategy is generally direct, rapid, economic and requires only ≈µL of input serum, suitable for point of care testing (POCT) applications.

Exploring the interaction and impact of probiotic and commensal bacteria on vitamins, minerals and short chain fatty acids metabolism

There is increasing evidence that probiotic and commensal bacteria play a role in substrate metabolism, energy harvesting and intestinal homeostasis, and may exert immunomodulatory activities on human health. In addition, recent research suggests that these microorganisms interact with vitamins and minerals, promoting intestinal and metabolic well-being while producing vital microbial metabolites such as short-chain fatty acids (SCFAs). In this regard, there is a flourishing field exploring the intricate dynamics between vitamins, minerals, SCFAs, and commensal/probiotic interactions. In this review, we summarize some of the major hypotheses beyond the mechanisms by which commensals/probiotics impact gut health and their additional effects on the absorption and metabolism of vitamins, minerals, and SCFAs. Our analysis includes comprehensive review of existing evidence from preclinical and clinical studies, with particular focus on the potential interaction between commensals/probiotics and micronutrients. Finally, we highlight knowledge gaps and outline directions for future research in this evolving field.

Bee-Associated Beneficial Microbes-Importance for Bees and for Humans

Bees are one of the best-known and, at the same time, perhaps the most enigmatic insects on our planet, known for their organization and social structure, being essential for the pollination of agricultural crops and several other plants, playing an essential role in food production and the balance of ecosystems, being associated with the production of high-value-added inputs, and a unique universe in relation to bees' microbiota. In this review, we summarize information regarding on different varieties of bees, with emphasis on their specificity related to microbial variations. Noteworthy are fructophilic bacteria, a lesser-known bacterial group, which use fructose fermentation as their main source of energy, with some strains being closely related to bees' health status. The beneficial properties of fructophilic bacteria may be extendable to humans and other animals as probiotics. In addition, their biotechnological potential may ease the development of new-generation antimicrobials with applications in biopreservation. The concept of "One Health" brings together fundamental and applied research with the aim of clarifying that the connections between the different components of ecosystems must be considered part of a mega-structure, with bees being an iconic example in that the healthy functionality of their microbiota is directly and indirectly related to agricultural production, bee health, quality of bee products, and the functional prosperity for humans and other animals. In fact, good health of bees is clearly related to the stable functionality of ecosystems and indirectly relates to humans' wellbeing, a concept of the "One Health".

Isolation and Characteristics of Extracellular Vesicles Produced by Probiotics: Yeast Saccharomyces boulardii CNCM I-745 and Bacterium Streptococcus salivarius K12

Numerous probiotic microorganisms have repeatedly been shown to produce nanometer-sized structures named extracellular vesicles (EVs). Recently, it has been suggested that similarly to whole microbial cells, EVs produced by probiotics may also demonstrate health benefits to the host, while their application does not involve the risk of infection caused by live microorganisms. In this work, we isolated EVs from two probiotic species originating from different taxonomic domains - yeast Saccharomyces boulardii CNCM I-745 and bacterium Streptococcus salivarius K12. The diameters of S. boulardii EVs were about 142 nm and for S. salivarius EVs about 123 nm. For S. boulardii EVs, 1641 proteins and for S. salivarius EVs, 466 proteins were identified with a liquid chromatography-coupled tandem mass spectrometry and then functionally classified. In both microbial species, metabolic proteins significantly contributed to the cargo of EVs comprising 25% and 26% of all identified vesicular proteins for fungi and bacteria, respectively. Moreover, enzymes associated with cell wall rearrangement, including enzymatically active glucanases, were also identified in EVs. Furthermore, probiotic EVs were shown to influence host cells and stimulate the production of IL-1β and IL-8 by the human monocytic cell line THP-1, and, at the same time, did not cause any remarkable reduction in the survival rate of Galleria mellonella larvae in this invertebrate model commonly used to evaluate microbial EV toxicity. These observations suggest that the EVs produced by the investigated probiotic microorganisms may be promising structures for future use in pro-health applications.

Role of Lactic Acid Bacteria in Insecticide Residue Degradation

Lactic acid bacteria are gaining global attention, especially due to their role as a probiotic. They are increasingly being used as a flavoring agent and food preservative. Besides their role in food processing, lactic acid bacteria also have a significant role in degrading insecticide residues in the environment. This review paper highlights the importance of lactic acid bacteria in degrading insecticide residues of various types, such as organochlorines, organophosphorus, synthetic pyrethroids, neonicotinoids, and diamides. The paper discusses the mechanisms employed by lactic acid bacteria to degrade these insecticides, as well as their potential applications in bioremediation. The key enzymes produced by lactic acid bacteria, such as phosphatase and esterase, play a vital role in breaking down insecticide molecules. Furthermore, the paper discusses the challenges and future directions in this field. However, more research is needed to optimize the utilization of lactic acid bacteria in insecticide residue degradation and to develop practical strategies for their implementation in real-world scenarios.

Probiotic Bacteria Survival and Shelf Life of High Fibre Plant Snack - Model Study

The study aimed to develop plant-based model snacks that are high in fibre, contain probiotic bacteria and are convenient for long-term storage. The research focused on selecting a suitable form of probiotic bacteria (active biomass, microencapsulated, freeze-dried), inoculation method (in the base mass or in the filling of a snack) and appropriate storage conditions (4°Cor 20 °C). The potential synbiotic properties were evaluated. The microencapsulated bacteria had the highest survival rate at 4 °C, while the freeze-dried bacteria showed better survival rates at 20 °C. Probiotics had a higher survival rate when enclosed inside snacks with a low water activity (aw = 0.27) peanut butter filling than in snacks without filling (aw = 0.53). Enclosing the probiotics in a low aw filling ensures their survival at ambient temperature for 5 months at a count higher than 6 log CFU/g. The snacks exhibited high antioxidant capacity (average 300 mg ascorbic acid equivalent/100 g), polyphenol content (average 357 mg gallic acid equivalent/100 g) and high fibre content (average 10.2 g/100 g). The sensory analysis showed a high overall quality of the snacks (average 7.1/10 of the conventional units). Furthermore, after six months of storage, significant changes were observed in the antioxidant properties, polyphenol content and texture of the snacks, while their sensory quality remained unchanged. Moreover, a potential synbiotic effect was observed. The method used to assess bacterial growth indicated significantly higher values in the model snacks compared to a control sample. Therefore, this study has effectively addressed the gap in knowledge regarding the survival of probiotics in snacks of this nature.

Changes in Garlic Quality during Fermentation under Different Conditions

One of the garlic processing methods is fermentation, which produces black garlic with completely different chemical, physical, sensory, culinary, and health-enhancing properties. Our study aimed to compare the influence of various processing conditions on the quality indicators of black garlic (BG). Samples of white garlic (WG) were placed in laboratory climatic chambers. BG1 samples were packed in plastic bags and vacuumed, BG2 and BG3 samples were packed in textile mesh bags. BG1 samples were fermented in 70% humidity at 50 °C for 28 days, BG2 samples in 85% humidity at 60 °C for 99 days, and BG3 samples in 80% humidity at 80 °C for 14 days. The dependence of changes in chemical composition, color, and texture of garlic on fermentation conditions was analyzed. Proximate composition analyses and antioxidant activity of WG and BG were performed using standard methods. It was established that regardless of the fermentation conditions, BG's chemical composition became richer than WG's. They significantly increased vitamin C content (1.5-5.8 fold), titratable acidity (14.7-21.0 fold), protein (1.4-3.2 fold), fiber (4.6-7.0 fold), and ash (1.2-3.9 fold) content, amount of total phenolic compounds (6.6-9.6 fold) and antioxidant activity (5.3-9.9 fold). Fermented garlic turned dark in color and soft and sticky in texture. The higher fermentation temperature (80 °C) but the shorter time (14 days) had the greatest positive effect on the quality of black garlic.

Impact of Lactic Acid Bacteria Fermentation Based on Biotransformation of Phenolic Compounds and Antioxidant Capacity of Mushrooms

Mushrooms contain phenolic compounds that possess health-promoting properties, including antioxidant effects. However, the low solubility and form of phenolic compounds affect their bioactivity and bioaccessibility. To overcome this limitation, our study investigates the fermentation of mushrooms to increase their free phenolic content and enhance their bioactivity. Our research focused on the impact of fermentation on both free and bound phenolic fractions (FPs and BPs, respectively) in Lentinula edodes and Lactarius deliciosus, which were successively fermented with Lactiplantibacillus plantarum LMG 17673 for 72 h. We examined the total phenolic content (TPC), phenolic profile, and antioxidant activity of both FPs and BPs. Our results showed that the TPC of BPs was higher than that of FPs in both mushrooms, with strong antioxidant capabilities. Fermentation significantly increased the TPC of FPs in both mushrooms, particularly after 24 h of fermentation. The TPC of BPs in mushrooms decreased during fermentation, indicating their release from the matrix. Additionally, we identified 30 bioactive compounds using UPLC-Q-TOF-MS/MS. Our study demonstrates for the first time that lactic acid bacteria fermentation of mushrooms with high phenolic content leads to the liberation of bound phenolics, enhancing their bioactivity and bioaccessibility.

Lactococcus lactis subsp. cremoris C60 Upregulates Macrophage Function by Modifying Metabolic Preference in Enhanced Anti-Tumor Immunity

Lactococcus lactis subsp. cremoris C60 is a probiotic strain of lactic acid bacteria (LAB) which induces various immune modifications in myeloid lineage cells. These modifications subsequently regulate T cell function, resulting in enhanced immunity both locally and systemically. Here, we report that C60 suppresses tumor growth by enhancing macrophage function via metabolic alterations, thereby increasing adenosine triphosphate (ATP) production in a murine melanoma model. Intragastric (i.g.) administration of C60 significantly reduced tumor volume compared to saline administration in mice. The anti-tumor function of intratumor (IT) macrophage was upregulated in mice administered with C60, as evidenced by an increased inflammatory phenotype (M1) rather than an anti-inflammatory/reparative (M2) phenotype, along with enhanced antigen-presenting ability, resulting in increased tumor antigen-specific CD8+ T cells. Through this functional modification, we identified that C60 establishes a glycolysis-dominant metabolism, rather than fatty acid oxidation (FAO), in IT macrophages, leading to increased intracellular ATP levels. To address the question of why orally supplemented C60 exhibits functions in distal places, we found a possibility that bacterial cell wall components, which could be distributed throughout the body from the gut, may induce stimulatory signals in peripheral macrophages via Toll-like receptors (TLRs) signaling activation. Thus, C60 strengthens macrophage anti-tumor immunity by promoting a predominant metabolic shift towards glycolysis upon TLR-mediated stimulation, thereby increasing substantial energy production.

Harnessing the Health and Techno-Functional Potential of Lactic Acid Bacteria: A Comprehensive Review

This review examines the techno-functional properties of lactic acid bacteria (LABs) in the food industry, focusing on their potential health benefits. We discuss current findings related to the techno-functionality of LAB, which includes acidification, proteolytic and lipolytic features, and a variety of other biochemical activities. These activities include the production of antimicrobial compounds and the synthesis of exopolysaccharides that improve food safety and consumer sensory experience. LABs are also known for their antioxidant abilities, which help reduce oxidative reactions in foods and improve their functional properties. In addition, LABs' role as probiotics is known for their promising effects on gut health, immune system modulation, cholesterol control, and general wellbeing. Despite these advantages, several challenges hinder the effective production and use of probiotic LABs, such as maintaining strain viability during storage and transport as well as ensuring their efficacy in the gastrointestinal tract. Our review identifies these critical barriers and suggests avenues for future research.

Valorization of Dairy and Fruit/Berry Industry By-Products to Sustainable Marinades for Broilers' Wooden Breast Meat Quality Improvement

The study aims to improve the quality of wooden breast meat (WBM) via the use of newly developed marinades based on selected strains of lactic acid bacteria (LAB) in combination with the by-products of the dairy and fruit/berry industries. Six distinct marinades were produced based on milk permeate (MP) fermented with Lacticaseibacillus casei (Lc) and Liquorilactobacillus uvarum (Lu) with the addition of apple (ApBp) and blackcurrant (BcBp) processing by-products. The microbiological and acidity parameters of the fermented marinades were evaluated. The effects of marinades on the microbiological, technical, and physicochemical properties of meat were assessed following 24 and 48 h of WBM treatment. It was established that LAB viable counts in marinades were higher than 7.00 log10 colony-forming units (CFU)/mL and, after 48 h of marination, enterobacteria and molds/yeasts in WBM were absent. Marinated (24 and 48 h) WBM showed lower dry-matter and protein content, as well as water holding capacity, and exhibited higher drip loss (by 8.76%) and cooking loss (by 12.3%) in comparison with controls. After WBM treatment, biogenic amines decreased; besides, the absence of spermidine and phenylethylamine was observed in meat marinated for 48 h with a marinade prepared with Lu. Overall, this study highlights the potential advantages of the developed sustainable marinades in enhancing the safety and quality attributes of WBM.

Chitosan Coating with Rosemary Extract Increases Shelf Life and Reduces Water Losses from Beef

This study aimed to evaluate the influence of films based on chitosan and rosemary extract on the physicochemical, microbiological, and oxidative characteristics of beef. Refrigerated steaks of Longissimus dorsi were distributed in a factorial arrangement (4 × 4) into four treatments consisting of four edible films (control; chitosan; chitosan + 4% rosemary extract; and chitosan + 8% rosemary extract) and four days of aging (0, 2, 4, and 8 days). Incorporating 4% or 8% rosemary extract into the chitosan film improved the characteristics of the films in terms of moisture absorption and elasticity. The edible coatings with chitosan and rosemary extract and the different days of aging increased the tenderness and decreased the lipid oxidation of beef. In addition, the chitosan films containing rosemary extract increased the water-holding capacity and decreased the cooking losses of beef. The films containing 4% and 8% rosemary extract decreased the development of mesophilic and psychrotrophic bacteria and Staphylococcus ssp. in beef. We recommend incorporating 4% rosemary extract into chitosan-based coatings to preserve the quality of refrigerated beef.

Fermentation of Orange Peels by Lactic Acid Bacteria: Impact on Phenolic Composition and Antioxidant Activity

Orange processing generates peel by-products rich in phenolic compounds, particularly flavanones like hesperidin and narirutin, offering potential health benefits. Utilizing these by-products is of significant interest in supporting Spain's circular bioeconomy. Therefore, the aim of this study was to investigate the fermentation of orange peels by different lactic acid bacteria (LAB) strains and its impact on phenolic composition and antioxidant activity. Three different LAB strains, two Lactiplantibacillus plantarum, and one Levilactobacillus brevis were utilized. The phenolic compounds were measured by HPLC-ESI-TOF-MS, and antioxidant activity was assessed using DPPH and ABTS methods. The growth of the LAB strains varied, showing initial increases followed by gradual declines, with strain-specific patterns observed. Medium acidification occurred during fermentation. A phenolic analysis revealed an 11% increase in phenolic acids in peels fermented by La. plantarum CECT 9567-C4 after 24 h, attributed to glycosylation by LAB enzymes. The flavonoid content exhibited diverse trends, with Le. brevis showing an 8% increase. The antioxidant assays demonstrated strain- and time-dependent variations. Positive correlations were found between antioxidant activity and total phenolic compounds. The results underscore the importance of bacterial selection and fermentation time for tailored phenolic composition and antioxidant activity in orange peel extracts. LAB fermentation, particularly with La. plantarum CECT 9567 and Le. brevis, holds promise for enhancing the recovery of phenolic compounds and augmenting antioxidant activity in orange peels, suggesting potential applications in food and beverage processing.

Whole-genome analysis suggesting probiotic potential and safety properties of Pediococcus pentosaceus DSPZPP1, a promising LAB strain isolated from traditional fermented sausages of the Basilicata region (Southern Italy)

Introduction

Many lactic acid bacteria (LAB) strains are currently gaining attention in the food industry and various biological applications because of their harmless and functional properties. Given the growing consumer demand for safe food, further research into potential probiotic bacteria is beneficial. Therefore, we aimed to characterize Pediococcus pentosaceus DSPZPP1, a LAB strain isolated from traditional fermented sausages from the Basilicata region of Southern Italy.

Methods

In this study, we analyzed the whole genome of the P. pentosaceus DSPZPP1 strain and performed in silico characterization to evaluate its applicability for probiotics and use in the food industry.

Results and Discussion

The whole-genome assembly and functional annotations revealed many interesting characteristics of the DSPZPP1 strain. Sequencing raw reads were assembled into a draft genome of size 1,891,398 bp, with a G + C content of 37.3%. Functional annotation identified 1930 protein-encoding genes and 58 RNAs including tRNA, tmRNA, and 16S, 23S, and 5S rRNAs. The analysis shows the presence of genes that encode water-soluble B-group vitamins such as biotin, folate, coenzyme A, and riboflavin. Furthermore, the analysis revealed that the DSPZPP1 strain can synthesize class II bacteriocin, penocin A, adding importance to the food industry for bio-enriched food. The DSPZPP1 genome does not show the presence of plasmids, and no genes associated with antimicrobial resistance and virulence were found. In addition, two intact bacteriophages were identified. Importantly, the lowest probability value in pathogenicity analysis indicates that this strain is non-pathogenic to humans. 16 s rRNA-based phylogenetic analysis and comparative analysis based on ANI and Tetra reveal that the DSPZPP1 strain shares the closest evolutionary relationship with P. pentosaceus DSM 20336 and other Pediococcus strains. Analysis of carbohydrate active enzymes (CAZymes) identified glycosyl transferases (GT) as a main class of enzymes followed by glycoside hydrolases (GH). Our study shows several interesting characteristics of the isolated DSPZPP1 strain from fermented Italian sausages, suggesting its potential use as a promising probiotic candidate and making it more appropriate for selection as a future additive in biopreservation.

The Profound Influence of Gut Microbiome and Extracellular Vesicles on Animal Health and Disease

The animal gut microbiota, comprising a diverse array of microorganisms, plays a pivotal role in shaping host health and physiology. This review explores the intricate dynamics of the gut microbiome in animals, focusing on its composition, function, and impact on host-microbe interactions. The composition of the intestinal microbiota in animals is influenced by the host ecology, including factors such as temperature, pH, oxygen levels, and nutrient availability, as well as genetic makeup, diet, habitat, stressors, and husbandry practices. Dysbiosis can lead to various gastrointestinal and immune-related issues in animals, impacting overall health and productivity. Extracellular vesicles (EVs), particularly exosomes derived from gut microbiota, play a crucial role in intercellular communication, influencing host health by transporting bioactive molecules across barriers like the intestinal and brain barriers. Dysregulation of the gut-brain axis has implications for various disorders in animals, highlighting the potential role of microbiota-derived EVs in disease progression. Therapeutic approaches to modulate gut microbiota, such as probiotics, prebiotics, microbial transplants, and phage therapy, offer promising strategies for enhancing animal health and performance. Studies investigating the effects of phage therapy on gut microbiota composition have shown promising results, with potential implications for improving animal health and food safety in poultry production systems. Understanding the complex interactions between host ecology, gut microbiota, and EVs provides valuable insights into the mechanisms underlying host-microbe interactions and their impact on animal health and productivity. Further research in this field is essential for developing effective therapeutic interventions and management strategies to promote gut health and overall well-being in animals.

Optimization of the fermentation process and antioxidant activity of mixed lactic acid bacteria for honeysuckle beverage

The aim of the research was to obtain a high healthcare honeysuckle beverage with strong antioxidant activity. Honeysuckle (Lonicera japonica Thunb) was used as the raw material in this experiment. The effects of fermentation temperature, fermentation time, lactic acid bacteria inoculation amount, and sugar addition amount on the sensory quality of honeysuckle beverage were investigated by single factor test and orthogonal test, and the best process was obtained. The physicochemical indexes and antioxidant activity of honeysuckle beverages fermented with lactic acid bacteria were studied. The results showed that the fermentation temperature of the beverage was 37 °C, the fermentation time was 24 h, the inoculation amount of Lactiplantibacillus plantarum and Lactobacillus acidophilus mixed starter (1:1) was 3%, and 8% white granulated sugar was added. The highest sensory score was 87.30 ± 0.17, which was the optimal process. The honeysuckle liquid mixed inoculation with Lactiplantibacillus plantarum and Lactobacillus acidophilus was fermented for 24 h. The number of viable bacteria reached 9.84 ± 0.02 lg cfu/mL, the pH value was 3.10 ± 0.01, and the total polyphenol content was 7.53 ± 0.03 mg GAE/g. The number of lactic acid bacteria, pH, total polyphenol content, and free radical scavenging rate were significantly increased (p < 0.05) compared with the non-inoculated and single-inoculated lactic acid bacteria. To sum up, it was concluded that a better quality beverage could be obtained by fermenting a solution of honeysuckle with Lactiplantibacillus plantarum and Lactobacillus acidophilus mixed fermentation agent, providing a new approach and new ideas for the development of deep processing and fermented beverages using honeysuckle.

Gamma-aminobutyric acid as a potential postbiotic mediator in the gut-brain axis

Gamma-aminobutyric acid (GABA) plays a crucial role in the central nervous system as an inhibitory neurotransmitter. Imbalances of this neurotransmitter are associated with neurological diseases, such as Alzheimer's and Parkinson's disease, and psychological disorders, including anxiety, depression, and stress. Since GABA has long been believed to not cross the blood-brain barrier, the effects of circulating GABA on the brain are neglected. However, emerging evidence has demonstrated that changes in both circulating and brain levels of GABA are associated with changes in gut microbiota composition and that changes in GABA levels and microbiota composition play a role in modulating mental health. This recent research has raised the possibility that GABA may be a potent mediator of the gut-brain axis. This review article will cover up-to-date information about GABA-producing microorganisms isolated from human gut and food sources, explanation why those microorganisms produce GABA, food factors inducing gut-GABA production, evidence suggesting GABA as a mediator linking between gut microbiota and mental health, including anxiety, depression, stress, epilepsy, autism spectrum disorder, and attention deficit hyperactivity disorder, and novel information regarding homocarnosine-a predominant brain peptide that is a putative downstream mediator of GABA in regulating brain functions. This review will help us to understand how the gut microbiota and GABA-homocarnosine metabolism play a significant role in brain functions. Nonetheless, it could support further research on the use of GABA production-inducing microorganisms and food factors as agents to treat neurological and psychological disorders.

Pediococcus pentosaceus Endocarditis in a Patient With Recent Transcatheter Aortic Valve Implantation and Liver Cirrhosis: A Case Report and Review of the Literature

Transcatheter aortic valve implantation (TAVI) is increasingly being used in the management of severe aortic stenosis, mainly in older and/or medically compromised patients, due to its minimally invasive nature. As in any valve replacement procedure, endocarditis is a recognized complication, more so in TAVI patients, in whom comorbidities are highly prevalent. We report the case of a 70-year-old male with a history of liver cirrhosis and a recent TAVI, who presented with recurrent fever and sustainedPediococcus pentosaceus bacteremia. The diagnosis of endocarditis was delayed, as the microorganism was initially discarded as a contaminant, given that Pediococci are rarely described as human pathogens. However, in cirrhotic patients, microbiota may cause intermittent bacteremia and thereby affect prosthetic valves. Transthoracic echocardiography was not helpful in validating the diagnosis, as is often the case in TAVI patients. Transesophageal echocardiography was deemed perilous, due to esophageal varices complicating the underlying cirrhosis. Therefore, endocarditis diagnosis was based on sustained bacteremia and Duke's criteria, including the presence of high fever, a predisposing cardiac lesion, splenic infarction, and the exclusion of an alternative diagnosis. Moreover, cirrhosis enhanced the side effects of treatment and led to the need for regimen changes and prolonged hospitalization. Given the precariousness of the situation, confirmation of treatment success by 2-deoxy-2-[fluorine-18]fluoro-D-glucose positron emission tomography-computed tomography (18F-FDG PET-CT) scan was sought. This is the first reported case of Pediococcus TAVI endocarditis in a cirrhotic patient, highlighting the unique challenges in the diagnosis and management of TAVI endocarditis in patients with co-existing conditions.

Poultry Gastrointestinal-derived Lactic Acid Bacteria (pGIT-d-LAB) Inhibit Multiple Antibiotics Resistance Bacterial and Fungal Pathogens

Background

To develop a probiotic formulation for poultry feed, a few poultry gastrointestinal derived lactic acid bacteria (pGIT-d-LAB) were isolated from chicken intestinal specimens and in vitro experiment was performed to evaluate their efficacy as potential probiotic candidate.

Methods

A total of 6 strains of LAB: Lactobacillus brevis (L. brevis), Lactobacillus acidophilus (L. acidophilus), Lactobacillus casei (L. casei), Pediococci spp, Lactobacillus fermentum (L. fermentum) and Lactobacillus plantarum (L. plantarum) were isolated and cultured for collection of Cell Free Supernatant (CFS). CFS collected was tested against pathogenic bacterial isolated from chicken feces as well as prevalent fungal pathogens, utilizing agar-well diffusion techniques. A preliminary investigation into the susceptibility of the pathogens to diverse antibiotics and antifungal drugs was conducted. Bacterial pathogens exhibiting resistance to a minimum of three classes of antibiotics were subsequently identified for pGIT-d-LAB CFS screening.

Results

The observed results revealed that the CFS derived from the isolates exhibited varying degrees of growth inhibition against different pathogens. Among the tested pGIT-d-LAB isolates, L. acidophilus demonstrated the most prominent zone of inhibition, measuring 18 mm against Klebsiella pneumoniae ZTAC 1233. Notably, Citrobacter diversus ZTAC 1255 showed resistance to all tested pGIT-d-LAB. Quantification of the metabolites produced was performed, and peak production levels was determined. L. acidophilus produced the highest amount of lactic acid (1.789g/l), Pediococci spp. produced the highest amount of diacetyl and H202 (1.918g/l) (0.0025g/l) at 48 hr peak values respectively.

Conclusion

The test isolates are potential probiotic candidates for controlling pathogens in poultry.

Investigation of volatile compounds during fermentation of Elaeagnus moorcroftii Wall.ex schlecht. juice by Bifidobacterium animalis subsp. lactis HN-3 and Lacticaseibacillus paracasei YL-29

The influence on and biotransformation of volatile compounds (VOCs) during fermentation of Elaeagnus moorcroftii Wall.ex Schlecht. juice (EWSJ) through single inoculation and co-inoculation of Bifidobacterium animalis subsp. lactis HN-3 (B.an3) and Lacticaseibacillus paracasei YL-29 (L.cp29) were analyzed through headspace-solid phase microextraction-gas chromatography-mass spectrometry. Compared with the B.an3- and L.cp29-fermented EWSJ, the B.an3 + L.cp29-fermented EWSJ had more increased 9 desirable flavor compositions and less decreased in or even elimination of 12 undesirable flavor compositions, and 3 new characteristic VOCs, formed through the interaction between B.an3 and L.cp29 were detected. In addition, biotransformations that led to an increase and a decrease in VOCs mainly involved 3 oxidation, 3 reduction, 1 hydrolysis, and 1 isomerization reactions. This study offers a theoretical basis for investigating the interaction effect of Lactobacillus and Bifidobacterium species on VOCs and developing lactic acid bacteria-fermented plant-based juices with lower sugar content and better flavor.

Succession of microbiota and its influence on the dynamics of volatile compounds in the semi-artificial inoculation fermentation of mulberry wine

To improve the delightful flavor of mulberry wine through semi-artificial inoculation fermentation with Saccharomyces cerevisiae, we studied the dynamics change of microbiota, along with the physicochemical properties and metabolite profiles and their interaction relationship during the fermentation process. The abundance of lactic acid bacteria (Weissella, Lactobacillus, Fructobacillus, and Pediococcus) increased significantly during fermentation, while yeasts gradually established dominance. The inter-kingdom network of the dominant genera analysis further identified the following as core microbiota: Alternaria, Botrytis, Kazachstania, Acremonium, Mycosphaerella, Pediococcus, Gardnerella, and Schizothecium. Additionally, pH, alcohol, and total acid were significantly affected by microbiota variation. Fourteen of all identified volatile compounds with key different aromas were screened using PCA, OPLS-DA, and rOAV. The network of interconnected core microbiota with key different aromas revealed that Kazachstania and Pediococcus had stronger correlations with 1-butanol, 3-methyl-, propanoic acid, and 2-methyl-ethyl ester.

Non-volatile and volatile compound changes in blueberry juice inoculated with different lactic acid bacteria strains

BACKGROUND

Lactic acid bacteria (LABs) are widely present in foods and affect the flavour of fermented cultures. This study investigates the effects of fermentation with Lactobacillus acidophilus JYLA-16 (La), Lactobacillus plantarum JYLP-375 (Lp), and Lactobacillus rhamnosus JYLR-005 (Lr) on the flavour profile of blueberry juice.

RESULTS

This study showed that all LABs strains preferentially used glucose rather than fructose as the carbon source during fermentation. Lactic acid was the main fermentation product, reaching 7.76 g L-1 in La-fermented blueberry juice, 5.86 g L-1 in Lp-fermented blueberry juice, and 6.41 g L-1 in Lr-fermented blueberry juice. These strains extensively metabolized quinic acid, whereas oxalic acid metabolism was almost unaffected. Sixty-four volatile compounds were identified using gas chromatography-ion mobility spectrometry (GC-IMS). All fermented blueberry juices exhibited decreased aldehyde levels. Furthermore, fermentation with La was dominated by alcohols, Lp was dominated by esters, and Lr was dominated by ketones. Linear discriminant analysis of the electronic nose and principal component analysis of the GC-IMS data effectively differentiated between unfermented and fermented blueberry juices.

CONCLUSION

This study informs LABs selection for producing desirable flavours in fermented blueberry juice and provides a theoretical framework for flavour detection. © 2023 Society of Chemical Industry.

A review of the effects of fermentation on the structure, properties, and application of cereal starch in foods

Fermentation is one of the oldest food processing techniques known to humans and cereal fermentation is still widely used to create many types of foods and beverages. Starch is a major component of cereals and the changes in its structure and function during fermentation are of great importance for scientific research and industrial applications. This review summarizes the preparation of fermented cereals and the effects of fermentation on the structure, properties, and application of cereal starch in foods. The most important factors influencing cereal fermentation are pretreatment, starter culture, and fermentation conditions. Fermentation preferentially hydrolyzes the amorphous regions of starch and fermented starches have a coarser appearance and a smaller molecular weight. In addition, fermentation increases the starch gelatinization temperature and enthalpy and reduces the setback viscosity. This means that fermentation leads to a more stable and retrogradation-resistant structure, which could expand its application in products prone to staling during storage. Furthermore, fermented cereals have potential health benefits. This review may have important implications for the modulation of the quality and nutritional value of starch-based foods through fermentation.

Comparative genomics of four lactic acid bacteria identified with Vitek MS (MALDI-TOF) and whole-genome sequencing

Lactic acid bacteria (LAB) can be used as a probiotic or starter culture in dairy, meat, and vegetable fermentation. Therefore, their isolation and identification are essential. Recent advances in omics technologies and high-throughput sequencing have made the identification and characterization of bacteria. This study firstly aimed to demonstrate the sensitivity of the Vitek MS (MALDI-TOF) system in the identification of lactic acid bacteria and, secondly, to characterize bacteria using various bioinformatics approaches. Probiotic potency-related genes and secondary metabolite biosynthesis gene clusters were examined. The Vitek MS (MALDI-TOF) system was able to identify all of the bacteria at the genus level. According to whole genome sequencing, the bacteria were confirmed to be Lentilactobacillus buchneri, Levilactobacillus brevis, Lactiplantibacillus plantarum, Levilactobacillus namurensis. Bacteria had most of the probiotic potency-related genes, and different toxin-antitoxin systems such as PemIK/MazEF, Hig A/B, YdcE/YdcD, YefM/YoeB. Also, some of the secondary metabolite biosynthesis gene clusters, some toxic metabolite-related genes, and antibiotic resistance-related genes were detected. In addition, Lentilactobacillus buchneri Egmn17 had a type II-A CRISPR/Cas system. Lactiplantibacillus plantarum Gmze16 had a bacteriocin, plantaricin E/F.

Fermentation of Rubus dolichocarpus juice using Lactobacillus gasseri and Lacticaseibacillus casei and protecting phenolic compounds by Stevia extract during cold storage

This study aimed to investigate the biological activities of Lactobacillus gasseri SM 05 (L. gasseri) and Lacticaseibacillus casei subsp. casei PTCC 1608 (L. casei) in the black raspberry (Rubus dolichocarpus) juice (BRJ) environment, and also the anti-adhesion activity against Salmonella typhimurium (S. typhimurium) in fermented black raspberry juice (FBRJ). Results showed significant anti-adhesion activity in Caco-2 epithelial cells. In the anti-adhesion process, lactic acid bacteria (LAB) improve intestinal health by preventing the adhesion of pathogens. Adding LAB to BRJ produces metabolites with bacteriocin properties. Major findings of this research include improved intestinal health, improved antidiabetic properties, inhibition of degradation of amino acids, and increase in the nutritional value of foods that have been subjected to heat processing by preventing Maillard inhibition, and inhibition of oxidation of foodstuff by increased antioxidant activity of BRJ. Both species of Lactobacillus effectively controlled the growth of S. typhimurium during BRJ fermentation. Moreover, in all tests, as well as Maillard's and α-amylase inhibition, L. gasseri was more effective than L. casei. The phenolic and flavonoid compounds increased significantly after fermentation by both LAB (p < 0.05). Adding Stevia extract to FBRJ and performing the HHP process showed convenient protection of phenolic compounds compared to heat processing.

Lactobacillus-derived components for inhibiting biofilm formation in the food industry

Biofilm, a microbial community formed by especially pathogenic and spoilage bacterial species, is a critical problem in the food industries. It is an important cause of continued contamination by foodborne pathogenic bacteria. Therefore, removing biofilm is the key to solving the high pollution caused by foodborne pathogenic bacteria in the food industry. Lactobacillus, a commonly recognized probiotic that is healthy for consumer, have been proven useful for isolating the potential biofilm inhibitors. However, the addition of surface components and metabolites of Lactobacillus is not a current widely adopted biofilm control strategy at present. This review focuses on the effects and preliminary mechanism of action on biofilm inhibition of Lactobacillus-derived components including lipoteichoic acid, exopolysaccharides, bacteriocins, secreted protein, organic acids and some new identified molecules. Further, the review discusses several modern biofilm identification techniques and particularly interesting new technology of biofilm inhibition molecules. These molecules exhibit stronger inhibition of biofilm formation, playing a pivotal role in food preservation and storage. Overall, this review article discusses the application of biofilm inhibitors produced by Lactobacillus, which would greatly aid efforts to eradicate undesirable bacteria from environment in the food industries.