Search Results (68)

This study aimed to assess the potential of meat-derived lactic acid bacteria (LAB) strains on the technological, microbiological, and physicochemical quality of beef sausages. Four fermented sausage treatments were prepared: (C) was produced without cultures; (S2A) was produced with Lactiplantibacillus plantarum S2A; (S4B) was produced with Lactiplantibacillus pentosus S4B; and (OP4) was produced with Lactiplantibacillus plantarum OP4. All tested treatments were characterized by high total aerobic mesophilic and LAB counts (7.48–8.16 and 7.68–8.20 log CFU/g, respectively). Overall, the sausages were characterized by insufficient microbiological quality, with a relatively high number of coagulase-positive staphylococci (3.35–4.26 log CFU/g). The sausages differed significantly in terms of color (p < 0.05). The C and S4B treatments were shown to be more red and yellow than S2A and OP4. Differences were observed in the texture assessment of the sausages, and the least hard were those of the OP4 treatment (288.01 N). Analysis of physicochemical parameters revealed no significant differences in water activity (p > 0.05). The starter culture treatments were characterized by a higher pH (5.69–5.82; p < 0.05) than the C treatment (5.42). Oxidation–reduction potential was significantly higher in the control sample (469.87 mV; p < 0.05). The highest peroxide value and TBARS (thiobarbituric acid reactive substances) values were recorded in S2A (1.98 meq O₂ kg⁻¹ of fat and 1.784 mg MDA kg⁻¹, respectively), while the lowest found in S4B and OP4 (1.65 meq O₂ kg⁻¹ of fat and 1.340 mg MDA kg⁻¹, respectively). Fatty acid profile analysis revealed that the use of LAB influenced the proportion of individual lipid fractions in fermented beef sausages. Free amino acid analysis revealed a significant effect of the LAB starter cultures used on the intensity of proteolytic transformations in sausages. The results indicate that indigenous strains of LAB can be effectively used as starter cultures in the production of fermented beef sausages. Their use contributes to improving the product’s physicochemical and textural properties and may also increase its oxidative stability and nutritional value. Full article

Camel milk is widely consumed in the world’s arid and semi-arid regions because of its favorable nutritional profile and associated human health benefits. The indigenous microbiota of raw camel milk is diverse and composed of different bacterial and fungal groups. This community drives spontaneous milk fermentation, resulting in a variety of traditional products, including Gariss, Shubat, Chal, Dhanaan, Lfrik, and Suusac (or Suusa), depending on geographic region and cultural practice. This fermented milk has improved sensory, nutritional, and health profiles, as well as an extended shelf life, compared to raw milk. Fermentation alters the microbial community structure, with lactic acid bacteria (LAB) consistently becoming dominant, while yeasts and molds are also detected in some products. These patterns have been identified using both culture-dependent and culture-independent approaches, including 16S rRNA gene sequencing and whole-genome shotgun metagenomics. However, the milk’s microbial composition is highly variable and is influenced by the original composition, geographical location, fermentation and hygiene practices. The detection of opportunistic pathogens such as E. coli, Salmonella and Listeria in some traditional products raises important food safety concerns. This review presents current knowledge on fermented camel milk microbiology using a cross-regional approach, identifying key gaps in microbial safety and process standardization to support wider acceptance and potential commercialization. Full article

Probiotic yeasts are increasingly proposed as adjuncts in fermented dairy products, but their behavior in kefir is still poorly described. This proof-of-concept study examined the effect of Saccharomyces boulardii CNCM I-745 supplementation on kefir produced with two traditional grain cultures and two industrial direct-vat-inoculation cultures during 21 days of cold storage at 4 °C. Microbiological, physicochemical, and sensory parameters were monitored on days 1, 7, 14, and 21. The starter culture type was the main source of variation, with traditional grain kefirs showing higher microbial counts and better sensory scores than industrial cultures. S. boulardii did not change pH, titratable acidity, Lactococcus spp., or total mesophilic aerobic bacteria, indicating that it can be added without disturbing the established kefir microbiota or its acidification pattern. The probiotic yeast increased the total yeast count, slightly modulated Lactobacillus spp., and gave a small improvement in taste–aroma scores. In the yeast-free industrial culture, S. boulardii maintained viable counts above 6 log CFU/g throughout storage, showing that it can act as the sole yeast source in kefir matrices that lack indigenous yeast. Traditional grain kefirs kept a more stable overall sensory quality across 21 days than industrial cultures. The multivariate analysis confirmed two largely independent quality dimensions, one related to lactic acid bacteria and acidity and another to sensory perception. The study supports the use of S. boulardii as a probiotic adjunct in kefir and provides preliminary effect-size information for future, adequately replicated trials. Full article

Artisanal cheese quality relies on a complex microbiota. The generalized use of commercial starter cultures has been associated with reduced microbial diversity, fueling interest in using indigenous lactic acid bacteria (LAB) as adjunct cultures. This study aimed to evaluate Ligilactobacillus salivarius SP36 as a starter or adjunct culture in ripened cheeses. Culture-based and culture-independent analyses were performed, together with the assessment of some physico-chemical parameters (pH, water activity, and color), including the profile of volatile compounds. All cheeses were microbiologically safe according to current EU legislation. The pH of the cheese made only with the SP36 strain was higher than those of the cheeses manufactured with a commercial starter (with or without strain SP36). L. salivarius SP36 modulated the aroma profile by increasing ethyl esters, alcohols, ketones, organic acids and sulphur compounds. LAB dominated all cheeses, with the highest microbial diversity in the cheese produced without the commercial starter. Lactiplantibacillus plantarum and Lacticaseibacillus paracasei isolates were obtained from all cheeses. Overall, L. salivarius SP36 seems a promising adjunct for mature cheeses, while autochthonous L. plantarum and L. paracasei isolates represent promising candidates for starter or adjunct cultures. Full article

Freeze–thaw cycles on the Qinghai–Tibetan Plateau inhibit microbial activity and challenge silage preservation. This paper aimed to elucidate how an indigenous, freeze–thaw-resistant Lactobacillus plantarum strain (LP160) improves oat silage quality under such stress. Oats were ensiled for 60 days under constant 20 °C (t) or freeze–thaw cycles (12 h at 20 °C/−5 °C; s) with or without LP160 inoculation. Samples after ensiling and 5-day aerobic exposure were analyzed for fermentation parameters, nutrients, microbiome, and non-targeted metabolomics using liquid chromatography–tandem mass spectrometry (LC-MS/MS). LP160 inoculation improved silage quality, as shown by the lower pH, ammoniacal nitrogen, neutral detergent fiber, acid detergent fiber contents as well as the greater amount of lactic acid. Key findings demonstrated that LP160 inoculation significantly enhanced Lactobacillus dominance, effectively curbed the growth of detrimental bacteria like Mucor, and regulated the microbial structure. During the aerobic exposure phase, the microbial community structures and successions varied under different temperature treatments. When inoculated under freeze–thaw conditions, the genus Bacillus increased, while Paenibacillus was not impeded. A total of 943 metabolites were identified, predominantly comprising amino acids, fatty acids, and the like. The expressions of metabolites with antioxidant and antibacterial properties were upregulated with LP160 inoculation. This led to the inhibition of protein hydrolysis and a reduction in ammonia–nitrogen production. The results of correlation analysis indicated that inoculating LP160 suppressed the proliferation of Mucor and enhanced the abundance of Torulaspora; meanwhile, the expression of L-palmitoylcarnitine involved in the fatty acid degradation pathway and fatty acid metabolism pathway was inhibited along with the generation of ammonia–nitrogen. Consequently, the degradation of fatty acids and proteins was restrained. The results of this paper provided new insights into the silage under freeze–thaw conditions. Full article

India’s diverse culinary heritage includes a wide spectrum of traditional fermented foods that harbour complex microbial communities essential for flavour development, preservation, and nutritional enhancement. These microorganisms—primarily lactic acid bacteria, yeasts, and molds—contribute functional properties that extend beyond food transformation to confer health benefits, including probiotic potential and metabolic regulation. This review integrates classical microbiological studies with modern molecular approaches such as metagenomics, metatranscriptomics, and metabolomics to elucidate the microbial diversity of Indian fermented foods. It highlights how geography, substrates, and ethnic traditions shape region-specific microbial consortia sustained through long-standing ethno-microbiological practices. Special focus is given to the glycemic modulation achieved through microbial fermentation, wherein organic acid production and resistant starch formation lower glycemic index and improve glucose metabolism. These processes, along with enhanced nutrient bioavailability, vitamin synthesis, and immunomodulation, illustrate the broader functional potential of fermentation. The review also examines interactions between food-borne microbes and the human gut microbiota, underscoring implications for personalized nutrition. Finally, it discusses modernization and commercialization strategies and outlines future directions involving multi-omics integration, indigenous starter cultures, and microbiome-based innovations to harness India’s microbial heritage for improved health and sustainable food development. Full article

Mafic mine tailings are highly resistant to bioleaching due to their silicate-rich composition, low sulfide content, and strong buffering capacity. This study aimed to assess the potential use of heterotrophic bioleaching to promote the release of metals from mafic tailings by evaluating the organic acid production and leaching capabilities of indigenous bacterial isolates and a known lactic acid producer, Lactiplantibacillus plantarum ATCC 8014. Indigenous acid-producing heterotrophic bacteria were isolated from a vanadium-titanium-bearing magnetite tailings in Québec, Canada, and screened for organic acid production in various culture media. The most active bacteria were L. plantarum and two isolates identified by their 16S rRNA gene as Enterococcus (CBGM-1C) and Acetobacter (BL-F) sp. They produced significant quantities of lactic acids, followed by acetic, citric, and gluconic acids during glucose metabolism, through fermentative or oxidative pathways. A two-step bioleaching process was implemented, consisting of an initial organic acid production phase followed by tailings leaching at 5% pulp density over 10 days at 30 °C. Metal solubilization and mineralogical analyses demonstrated strain-dependent and metal-specific mobilization, with zinc being the only element efficiently leached (up to ~74% recovery by L. plantarum). XRD analyses confirmed partial dissolution and reduced crystallinity of key silicate phases without secondary mineral formation. These findings indicate that heterotrophic leaching can selectively mobilize more labile metals such as Zn from alkaline, silicate-rich tailings, although its overall efficiency for refractory elements remains limited under the tested conditions. Full article

The first step to selecting interesting lactic acid bacteria for commercial use is testing their resistance to different physicochemical stresses. In this study, we evaluated the viability of Enterococcus faecium and Enterococcus durans, obtained from two traditional fermented cheeses, subjected to several stresses (thermal, osmotic, acidic, alkaline, oxidative, detergent, and alcoholic). The assessment of cell viability was conducted via flow cytometry (FCM) combined with nucleic-acid double staining (NADS) and was compared to the conventional plate count method (CFU). The findings from the two approaches indicated that Enterococcus faecium and Enterococcus durans demonstrated a substantial proportion of viable cells following exposure to osmotic, thermal, and acidic stress. The alkaline stress treatment does not diminish the proportion of viable cells. Both strains exhibited extensive sensitivity to SDS, oxidative stress, and experienced total cell death under alcoholic stress. We observed a satisfactory correlation between cell viability as measured by FCM and CFU under all stress conditions. These data demonstrate the existence of indigenous strains of Enterococcus spp. that exhibit notable stress resistance. FCM for viability enumeration is better than the conventional plate counting method due to its rapid results and precision, which offer an effective evaluation of live, dead, and permeabilised cells. This technique holds promise for physiological state research in dairy applications to evaluate the quality of fermented products and the viable cell count for probiotic manufacturing. Full article

Socol is an artisanal meat product typical of Southeast Brazil. It is made from pork loin and ripened at room temperature. This work aimed to isolate, quantify, and identify lactic acid bacteria (LAB) in Brazilian dry-cured loin (Socol) as well as evaluate their in vitro probiotic potential. LAB were found in high amounts, varying from 2.5 × 10³ to 9.2 × 10⁶ CFU g⁻¹. Eleven isolated bacteria were identified by Matrix-Assisted Laser Desorption Ionization–Time-Of-Flight/Mass Spectrometry (MALDI-TOF/MS). Of these, six strains (Latilactobacillus brevis SFC1A, Latilactobacillus sakei SFC2A, Latilactobacillus curvatus SFC6A, Pediococcus acidilactici SFC9A, Latilactobacillus curvatus SFC11A, and Pediococcus pentosaceus SFC11B) were submitted to in vitro probiotic tests. All were tolerant to bile salts and five of them to artificial gastric juice, and were all sensitive to tetracycline, chloramphenicol, and erythromycin. L. brevis SFC1A and P. acidilactici SFC9A inhibited all tested pathogenic bacteria and showed the broadest in vitro probiotic activity. Thus, they would be recommended as starter cultures for the elaboration of novel fermented meat products and to compose a bank of indigenous bacteria, as well as contribute to preserving Socol microbiota. Full article

Milk contains wide microbial diversity, composed mainly of lactic acid bacteria (LAB), which are used as probiotics for both humans and livestock. We isolated, characterized, and evaluated LAB from indigenous Saudi Arabian camel milk to assess its probiotic potential, including antagonistic activity (against Methicillin-Resistant Staphylococcus aureus (MRSA) and Klebsiella pneumoniae), survivability in simulated gastric juice, tolerance to bile salts, cell surface hydrophobicity, auto- and co-aggregation, and antibiotic susceptibility tests. The two most promising LAB strains showed probiotic potential and were identified as Leuconostoc mesenteroides based on 16S rRNA gene sequences. These strains inhibited all pathogens tested to varying degrees and were resistant to kanamycin and vancomycin. None of the LAB cultures demonstrated hemolytic or gelatinase activity. Overall, the current data suggests that camel milk has substantial potential for introducing probiotics/LAB strains into the human food chain, making camel milk a potentially sustainable food. Full article

Guacamole is an avocado-based Ready-to-Eat (RTE) salad product, consumed globally and increasingly popular due to health trends. Its composition, characterized by a relatively neutral pH and stable water activity, creates favorable conditions for microbial proliferation, leading to spoilage, and resulting in a limited shelf-life of the product. Natural antimicrobials, such as essential oils (EOs), organic acids, chitosan, etc. have the potential to control microbial populations, therefore delaying spoilage and consequently providing a shelf-life extension. This study evaluated the effects of different concentrations of the selected natural antimicrobials [citric acid, mastic essential oil (EO), chitosan] added, either singly or combined, on the indigenous microbial (“spoilage”) association of guacamole during two storage conditions (chill, mild) for a period of 7 days. Results showed that of all the species enumerated in the present study, yeasts and molds were the predominant species, followed by Lactic Acid Bacteria (LAB), Enterobacteriaceae and Pseudomonas spp., at populations ranging from 3.6 to 2.0 and 2.65 to 1.45 log CFU/g, at 4 and 10 °C, respectively, in the control (CNL) avocado-based salad samples. Reductions in the range 1 to 2 log CFU/g were obtained for Pseudomonas spp., Enterobacteriaceae, and yeasts and molds under the triple antimicrobial treatment (citric acid, mastic EO, chitosan; CACHM), whereas interestingly, for LAB the highest reduction (1.74 log CFU/g) was achieved by chitosan and mastic EO (CHM), followed by CACHM (1.5 log CFU/g). Refrigeration (chill, 4 °C) as a hurdle acted as an additional barrier delaying microbial growth in all samples. To our knowledge, this is the first study to (a) evaluate the effect of natural antimicrobials (added, either singly or combined), namely citric acid, mastic EO, and chitosan on the microbiota of guacamole and (b) assess the possible application of the aforementioned natural antimicrobials in potentially increasing the shelf-life of a RTE avocado-based product (guacamole, in this study). Full article

Malolactic fermentation (MLF), a key enological process for wine deacidification and aroma and flavor development, is predominantly mediated by lactic acid bacteria. This study characterized 342 indigenous Lactiplantibacillus plantarum (L. plantarum) isolates, a potential starter species underexploited for MLF, from China’s Jiaodong Peninsula wine regions through polyphasic analysis. Thirty strains with high tolerance to wine stress conditions and efficient malate metabolism were selected. Among these, two high-performance strains, P101 and J43, exhibited superior MLF kinetics. Their applications had almost no effect on the wine’s basic physicochemical parameters, color parameters, and individual phenolic contents. Solid-phase microextraction–gas chromatography–mass spectrometry (SPME-GC-MS) analysis revealed that these strains significantly enhance key aroma compound contents in wines, including ethyl acetate, ethyl lactate, ethyl 2-methylbutyrate, and nerol, contributing more floral and fruity aroma characteristics. These indigenous L. plantarum strains, novel microbial starter cultures, demonstrate dual functionality in enhancing wine quality through controlled fermentation while supporting microbial biodiversity through the development of region-specific strain resources. Full article

Indigenous Mexican fermented beverages, such as pulque, colonche, tepache, and water kefir, are pillars of the country’s cultural and gastronomic heritage. Their sensory attributes and health-promoting properties arise from complex microbial consortia, in which lactic acid bacteria (LAB), mainly Lactobacillus and Leuconostoc, acetic acid bacteria (AAB), primarily Acetobacter, and yeasts such as Saccharomyces and Candida interact and secrete exopolysaccharides (EPSs). Dextran, levan, and heteropolysaccharides rich in glucose, galactose, and rhamnose have been consistently isolated from these beverages. EPSs produced by LAB enhance the viscosity and mouthfeel, extend the shelf life, and exhibit prebiotic, antioxidant, and immunomodulatory activities that support gut and immune health. Beyond food, certain EPSs promote plant growth, function as biocontrol agents against phytopathogens, and facilitate biofilm-based bioremediation, underscoring their biotechnological potential. This review integrates recent advances in the composition, biosynthetic pathways, and functional properties of microbial EPSs from Mexican fermented beverages. We compare reported titers, outline key enzymes, including dextransucrase, levansucrase, and glycosyltransferases, and examine how fermentation variables (the substrate, pH, and temperature) influence the polymer yield and structure. Finally, we highlight emerging applications that position these naturally occurring biopolymers as sustainable ingredients for food and agricultural innovation. Full article

Koshu wine, produced from the indigenous Japanese grape Vitis vinifera L. cv. Koshu exhibits a lower pH than other white wines, hindering malolactic fermentation (MLF) by lactic acid bacteria (LAB). Here, we aimed to isolate LAB strains capable of performing MLF under these challenging conditions to improve wine quality. Sixty-four Oenococcus oeni and one Lactobacillus hilgardii strain were isolated from Koshu grapes and wines that had undergone spontaneous MLF. MLF activity was assessed under varying pH, SO₂, and ethanol conditions in modified basal medium (BM) and Koshu model wine media. Expression of stress-related genes was analyzed using real-time PCR. Carbon source utilization was evaluated via API 50CH assays. All isolates degraded malic acid and produced lactic acid at 15 °C and pH 3.2 in BM without reducing sugars. Seven strains, all identified as O. oeni, demonstrated MLF activity at pH 3.0 in modified BM lacking added reducing sugars or tomato juice. Six wine-derived strains tolerated up to 12% ethanol, whereas the grape-derived strain was inhibited at 10%. In a synthetic Koshu wine model (13% ethanol, pH 3.0), wine-derived isolates exhibited higher MLF activity than commercial starter strains. In high-performing strains, mleA was upregulated, and most isolates preferred fructose, arabinose, and ribose over glucose. These findings suggest that indigenous O. oeni strains from Koshu wine possess unique stress tolerance and metabolic traits, making them promising candidates for region-specific MLF starter cultures that could enhance Koshu wine quality and terroir expression. Full article

The production of fermented sausages from poultry meat using traditional technologies and natural maturation conditions is a major challenge. The aim of this study was to identify indigenous microbiota with antilisterial activity from an innovative, additive-free, traditionally fermented chicken sausage. Isolates (n = 88) of lactic acid bacteria (LAB) were collected during maturation and subjected to MALDI-TOF mass spectrometry identification. The capacity to combat Listeria was screened against five strains using the agar well diffusion method in 63 selected LAB isolates. MALDI-TOF mass spectrometry identified four different LAB genera, namely Enterococcus, Lactococcus, Leuconostoc and Lactobacillus, the proportions of which differed significantly during the production phases (p < 0.001). Enterococcus faecalis was the most prevalent LAB species in the initial sausage dough. The presence of lactococci (Lactococcus lactis) and enterococci was detected during the 14- and 30-day ripening period and was gradually displaced by leuconostocs and lactobacilli. Lactobacilli appeared to be abundant during the central and late maturation phases, and consisted of only two species—Latilactobacillus sakei and Latilactobacillus curvatus. In total, 38 LAB isolates (60%) showed antilisterial activity toward at least one Listeria indicator strain. The proportions of antilisterial LAB differed significantly during sausage maturation. Inhibitory activity against all indicator Listeria was detected in the neutralized cell-free supernatants of five strains of Enterococcus faecalis, two L. sakei strains and one Leuconostoc mesenteroides strain. The antilisterial activity observed in the indigenous LAB revealed the possible role of L. sakei as a bioprotective culture, as well as the role of Ln. mesenteroides and E. faecalis as bacteriocin producers, for practical applications. Full article