Search Results (188)

Biopreservation using lactic acid bacteria has gained a growing interest as an alternative to chemical preservatives and/or as a complementary tool to prevent fungal spoilage in dairy products. Among the action mechanisms of antifungal LAB, competitionexclusion for trace elements has recently been highlighted. To further investigate this mechanism, two antifungal LAB strains, Lactiplantibacillus plantarum L244 and Lactobacillus rhamnosus CIRM-BIA1759, were studied in a yogurt model. Firstly, the antifungal activity of these strains against four main dairy spoilage fungi (Penicillium biforme, Mucor racemosus, Galactomyces geotrichum and Yarrowia lipolytica) was evaluated with or without trace element (6 metals and 12 vitamins) supplementation. Only manganese supplementation led to a suppression of the antifungal activity of both L. plantarum L244 and L. rhamnosus CIRM-BIA1759 against P. biforme and/or Y. lipolytica. The scavenging of trace elements was then measured using HR-ICP-MS in both cell-free yogurt whey and fungal biomass. HR-ICP-MS results showed a significant scavenging of Mn in L. plantarum L244 and L. rhamnosus CIRM-BIA1759 whey, as well as Cu for L. rhamnosus CIRM-BIA1759. Moreover, element uptake profiles, including metal and non-metal elements, for each of the target fungi were affected by the use of antifungal cultures. Finally, the role of competitionexclusion for manganese in the inhibition of 25 fungal spoilers was evaluated via oCelloScope growth follow-up. Growth inhibition by antifungal LAB strains was suppressed after Mn supplementation in cell-free whey for the 16 (out of 25) fungi initially inhibited without Mn supplementation. The nine other fungi were not inhibited or were poorly inhibited in the different tested conditions. This study confirmed the role of competitionexclusion for Mn in the antifungal activity of L. plantarum L244 and L. rhamnosus CIRM-BIA1759 strains but also revealed that this mechanism is not generic among fungal species, as the growth behavior of several tested species was not impacted by Mn scavenging. Full article

The eutrophication of aquatic ecosystems often triggers the excessive growth of cyanobacteria, many of which release toxic metabolites such as microcystins (MCs). When irrigation water is contaminated by these compounds, adverse consequences may arise for plants as well as for animal and human health. In contrast, certain non-toxic cyanobacterial species like Limnospira platensis are increasingly regarded as valuable tools for sustainable agriculture, given their ability to enhance plant nutrition, growth, yield, and stress tolerance while also mitigating the detrimental impacts of MCs. The present work aimed to investigate the potential of L. platensis extract to enhance growth, physiological responses, and tolerance of radish (Raphanus sativus) plants stressed with Microcystis aeruginosa extract containing microcystins. Experiments were conducted in a hydroponic system under controlled environmental conditions, where radish seedlings were cultivated in perlite and exposed for 45 days to M. aeruginosa extract (10 and 40 µg/L of MCs) and L. platensis extract (0.1 and 1 g/L), applied either separately or in combination. The results showed that the application of L. platensis extract, especially at 1 g/L in combination with 40 µg/L of MCs, decreased the bioaccumulation of MCs from 8.81 to 5.35 µg/kg FW in the leaves and from 14.64 to 10.15 µg/kg FW in the taproots. In addition, it significantly stimulated radish growth and improved several biochemical parameters. In contrast, exposure to MCs at 10 and 40 µg/L negatively affected growth, chlorophyll pigments and protein contents while promoting the accumulation of malondialdehyde (MDA), polyphenols and sugars. The activities of peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) were also increased under MCs stress, suggesting activation of the antioxidant defense system in response to oxidative damage. Combinations of MCs with L. platensis extract, especially at 1 g/L, improved antioxidant enzyme activities by significantly reducing MDA levels, biometric parameters, chlorophyll pigment, and protein and sugar contents. These results indicate that the application of L. platensis extract as a biostimulant can improve radish development, growth, and tolerance to MC-induced stress. Full article

Fermented sausages are popular worldwide due to their sensory and nutritional characteristics, as well as their convenience for storage and consumption. The production and consumption of meat products are associated with negative impacts from the risks of high sodium intake, such as cardiovascular disease and hypertension. Salt (NaCl) plays an important role in the preservation, water loss during drying, reduction in water activity, and sensory characteristics of meat and other fermented food products. NaCl reduction is considered a challenge because it affects the sensory properties of meat and can compromise the safety and microbiological parameters related to the spoilage of the fermented meat product. The use of microorganisms, such as LAB, has been studied as an innovative way to substitute traditional preservatives. They produce various metabolites, including bioactive and antimicrobial substances that are actively involved in health benefits and guarantee the safety of meat products. These natural substances produced by bacteria extend shelf life by inhibiting spoilage and pathogenic microorganisms. This review discusses the potential application of lactic acid bacteria in the reformulation of fermented sausages, challenges, and beneficial effects on sensorial, safety, and health properties. Full article

This study explores tomato agri-food residues as sources of bacteria with bioprotective potential to enhance product shelf-life and safety. A total of 245 bacterial strains were isolated, comprising predominantly Pseudomonas (52%) and Bacillus (44%) spp., with lactic acid bacteria (LAB) present at lower levels (4%). The antimicrobial activity of these isolates was assessed against pathogenic and spoilage bacteria and phytopathogenic molds. Notably, the Bacillus isolate TRB1-7 exhibited moderate activity against L. monocytogenes (inhibition halo diameter: 10.64 mm), while Pseudomonas and LAB isolates showed limited or no inhibition. Antifungal assays highlighted significant antifungal potential for Bacillus isolates. Results showed that 16% and 15% of the 245 isolates inhibited F. oxysporum and C. acutatum growth, respectively. Nine of these isolates underwent acid-adaptation and were evaluated against the selected molds using Potato Dextrose Agar (PDA) at pH 4.0 to simulate tomato conditions. Only isolate BRZ3-2, identified as B. aerius, was adapted to acidic conditions and inhibited F. oxysporum by 25%. Experiments on tomato-based agar at the same pH showed no inhibition by Bacillus isolates. These results suggest that tomato microbiota harbors acid-tolerant Bacillus strains with potential for post-harvest bio-preservation. Further studies on strains TRB1-7 and BRZ3-2 are required to develop effective bioprotective applications. Full article

Listeria monocytogenes is a highly pathogenic foodborne bacteria that is responsible for listeriosis, a serious infectious disease characterized by a high mortality rate among vulnerable populations such as the immunocompromised, pregnant women and the elderly. Moreover, its pathogenicity, its capacity to persist in food processing environments and proliferate in adverse conditions like low temperatures and high salt concentrations, and its ability to generate biofilms make it a major contaminant affecting ready-to-eat food products. In response to this potential public health threat, the agrifood industry has traditionally adopted conventional control methods including thermal treatment and chemical preservatives. However, these approaches have their limitations, especially in terms of efficacy, organoleptic impact and consumer acceptability. In this context, innovative biocontrol strategies are increasingly attracting interest among scientific and industrial stakeholders. This review reports a global overview of the mechanisms involved in the pathogenicity and survival abilities of Listeria monocytogenes in food commodities and processing equipment, as well as a current state of the use of protective cultures and antimicrobial peptides as promising biological-based approaches to control and prevent Listeria monocytogenes in food products and food processing. Full article

Enterohemorrhagic Escherichia coli (EHEC) forms persistent biofilms on meat processing surfaces, posing a significant cross-contamination risk. This study assessed the antagonistic capacity of lactic acid bacteria (LAB) against EHEC under meat-processing-like conditions. Three LAB strains were tested in planktonic co-culture with EHEC at 12 °C, all displaying bactericidal activity. In biofilm assays on stainless steel, LAB reduced EHEC biofilms without affecting their own viability. LAB cell-free supernatants further inhibited EHEC biofilms by 2.6–3.5 log CFU/cm², highlighting the role of secreted antagonistic compounds. Among the tested strains, Pediococcus pentosaceus CRL 2145 showed the strongest effect and was selected for deeper analysis. Fluorescence microscopy confirmed EHEC cell death within mixed biofilms. Proteomic profiling of CRL 2145 under mixed-biofilm conditions revealed 162 differentially expressed proteins, with 156 upregulated. These proteins were mainly associated with metabolism, transcription, translation, and stress response pathways, suggesting a multifactorial inhibitory mechanism involving metabolic dominance, physical competition, and secretion of antagonistic molecules. Overall, this study deepens our understanding of the molecular and physiological aspects of LAB–EHEC interaction. P. pentosaceus CRL 2145 emerges as a promising biocontrol agent that could be applied, alone or with its supernatants, to meat processing surfaces to improve food safety. Proteomic data: ProteomeXchange PXD067300. Full article

This research work evaluated the application of whey-based edible coatings to cheeses. Coatings were prepared with a bioprotective culture (BC) containing Lacticaseibacillus paracasei and Lacticaseibacillus rhamnosus alone, or in conjunction with thyme essential oil (TEO). The samples containing the BC or the BC plus TEO were compared with cheeses without coating, with cheeses with whey-based coatings without BC or TEO, and with cheeses treated with natamycin. The cheeses were evaluated regarding their physicochemical, microbiological, and sensory properties. All cheeses produced were classified as full-fat (≥45–60% fat in dry matter—FDM) and semihard (>54–<63% moisture in the defatted cheese—MDC), with an exception made for the control cheese, which presented lower levels of MDC, graded as hard (>49–<56% MDC). Most of the parameters evaluated presented significant differences between samples and as a result of ripening time. Regarding color parameters, it was observed that, after ripening, the external color of the samples with the whey coating presented higher lightness values (L*), higher a* values, and lower b* values. These differences clearly resulted from the white color imparted by the coating. Significant differences were also observed with respect to the texture parameters of the cheeses. The samples containing the BC or the BC plus TEO presented higher values for hardness and chewiness. In what concerns the microbiological evaluation, in all cases, lactic acid bacteria counts increased from log 7.5–8 CFU/g on the first day to ca. log 10 CFU/g at the end of the ripening period. Yeast and mold counts were significantly lower in samples containing the BC or the BC plus TEO, with values of ca. log 3 CFU/g and log 2.5 CFU/g, respectively. These values are like those obtained in samples with natamycin, with 1–2 log cycles below those of cheeses without treatment. However, the use of BC and BC plus TEO had a negative impact on the sensory properties of cheeses. Future work should evaluate the synergistic effect of different BCs and EOs. Full article

Salinity is a major limiting factor for all food crops, mainly Chinese cabbage. This study aimed to investigate the effects of biochar (BC) on physiological, biochemical, and molecular responses of Chinese cabbage grown under salinity stress in an open field. We supplied three concentrations of BC (5, 10, and 15 t/ha) to the 200 mM NaCl salinity-stress-induced field, which enhanced physical and chemical properties of the soil. Under salinity stress, BC increased photosynthetic pigments and reduced proline and H₂O₂ contents. Notably, 5 t/ha BC boosted plant growth, biomass, and yield by >40% and inhibited ROS accumulation under salinity stress. BC also promoted the concentrations of various key micronutrients, particularly Fe and Zn, in Chinese cabbage under salinity stress, which may contribute to improving the nutrient content. BC under salinity stress significantly induced the expression of NHX family genes (BoNHX1 and BoNHX2). Among these, the BoNHX1 gene was found to be highly expressed in shoot and root tissues of Chinese cabbage grown under salinity stress with BC. Identification of this key candidate gene will lay the groundwork for further functional characterization studies to elucidate its role under salinity stress with BC. This study comprehensively analyzes the physiological, biochemical, and molecular impacts of BC application in Chinese cabbage under salinity stress. This study found that the application of 5 t/ha significantly improved various physiological and biochemical traits of Chinese cabbage under salinity stress compared to the other treatments. The outcome of this study provides novel insights into the bioprotective role of BC, offering a valuable foundation of organic supplements for farmers while also highlighting potential research directions for enhancing crop resilience and productivity in economically important crops. Full article

The use of non-Saccharomyces species is gaining momentum in modern winemaking as part of broader efforts to reduce chemical inputs and adapt to climate-driven challenges. In this study, Furmint grapes were harvested at two distinct ripeness levels: an early harvest with healthy berries and a late harvest that included botrytized fruit. Two oenological protocols were compared: a conventional sulphur dioxide-based protocol and an alternative bioprotection-oriented approach that minimized SO₂ additions. Bioprotection was carried out using Metschnikowia pulcherrima, followed by sequential inoculation with Torulaspora delbrueckii and Saccharomyces cerevisiae. Grape-derived tannins (from skin and seed) were also added to inhibit oxidative enzymes such as laccase. Fermentation was monitored using standard analytical techniques, with volatile aroma profiles characterized by HS-SPME-GC-MS. Results showed that harvest timing and botrytization strongly influenced the chemical composition of the wines. Moreover, the treatment protocol had a marked effect on the final sensory profile. Wines produced with the bioprotection-oriented protocol displayed enhanced aromatic complexity, particularly through higher concentrations of esters and higher alcohols. Overall, the alternative protocol involving M. pulcherrima-based bioprotection resulted in wines with more pronounced floral and fruity notes, supporting its potential as a viable strategy for producing expressive wines under evolving climatic conditions. Full article

The impacts of Lactilactilactobacillus sakei (LS), Pediococcus acidilactici (PA), and Latilactobacillus curvatus (LC) on quality properties, protein and lipid oxidation, and microbial dynamics of pickled pepper rabbit meat during refrigerated storage (4 °C for 1, 3, 5, and 7 days) were investigated. The results showed that the addition of lactic acid bacteria bioprotective agents effectively reduced the pH of pickled pepper rabbit meat, inhibited protein and lipid oxidation, suppressed the growth and proliferation of spoilage bacteria, and maintained favorable textural characteristics. Among the tested strains, Latilactobacillus curvatus exhibited the most significant preservation effects throughout the storage period. On day 7 of storage, the TBARS value of the LC group was 20.60% lower than that of the LS group and 14.68% lower than that of the PA group. Similarly, the total carbonyl content was 12.30% lower than the LS group and 6.21% lower than the PA group, while the total sulfhydryl content was 20.81% and 10.12% higher, respectively. Additionally, the TVB-N value was 11.91% lower than the LS group and 4.37% lower than the PA group. Additionally, the Latilactobacillus curvatus group maintained a lower pH, superior elasticity, chewiness, and cohesiveness, while effectively inhibiting spoilage bacterial growth and proliferation. In conclusion, Latilactobacillus curvatus was the most effective bioprotective agent for preserving the storage characteristics of pickled pepper rabbit meat. Full article

This study developed a technology for restructured meat products (RMPs) from culled cow meat using the bioprotective culture Lactobacillus sakei (SafePro B-2, 10¹¹ CFU/g) and fortification with L-selenomethionine or zinc citrate. Four variants (Control, SafePro B-2, SafePro B-2 + Se, and SafePro B-2 + Zn) were produced under identical processing conditions and assessed for microbiological, physicochemical, textural, colorimetric, antioxidant, histological, mineral, and amino acid properties. Protein content remained high across all samples (up to 18.7%), while moisture increased by up to 1.4% compared to the control. The Zn-enriched sample showed the greatest cohesiveness and resistance to deformation (p < 0.05), with color stability under light exposure improving by up to 12.5%. Despite a reduction in FRAP antioxidant activity (up to 30.8% in buffer extract), the Zn-fortified product exhibited the highest levels of key essential amino acids, including leucine (12.9 mg/g) and lysine (12.6 mg/g). Microbiological analysis confirmed low total aerobic mesophilic counts (≤3.1 log CFU/g), with no detection of Salmonella spp. or Listeria monocytogenes. Histological evaluation revealed denser and more homogeneous protein matrices in fortified variants. Overall, L. sakei-driven bioprotection combined with Se/Zn fortification improved the safety and functional and nutritional characteristics of RMP from low-value beef, supporting sustainable and circular meat production. 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

This study aimed to verify, under real operating conditions, the effectiveness of protective lactic acid bacteria (LAB) culture in counteracting the development of late blowing defects in Valtellina Casera PDO cheese and its impact on product sensory characteristics. Thirty-four LAB isolated from Bitto and Valtellina Casera PDO cheeses were screened for anti-Clostridium activity. Lacticaseibacillus casei VC201 was able to inhibit all the indicator strains through organic acid production. Valtellina Casera PDO cheese-making was performed twice in three dairy farms using a commercial autochthonous starter culture with and without the addition of the protective culture VC201. Cheese was ripened both at 8 °C and 12 °C and analyzed after 70 and 180 days for LAB population, proteolysis, and lipolysis evolution as well as sensory impact. Cheeses with the addition of the VC201 strain showed higher contents of rod-shaped LAB throughout the ripening at both temperatures. The protective culture decreased the production of butyric acid at 70 days, especially at 8 °C (−15.4%), while butyric fermentation was occasionally lightly observed at 12 °C. The sensory profile was favorably impacted by the higher relative proportion of short-chain fatty acids (SCFFAs, C2–C8), which was especially pronounced at 8 °C and persisted for 180-day ripening (23.91% vs. 18.84% at 70 days and 23.84 vs. 21.71 at 180 days of ripening). The temperature and time of ripening had a significant effect on the free fatty acid content of the cheese samples in all three classes (SCFFA, MCFFA, and LCFFA). The cheese made with Lcb. casei VC201 was preferred, according to the sensory evaluation, being perceived as less acidic, less bitter, tastier, and with more intense flavor. Protective cultures can represent a practical way to reduce late blowing defects in Valtellina Casera cheese production while maintaining adherence to its PDO regulatory requirements. Full article

Arbuscular mycorrhizal fungi (AMF) play a key role in enhancing plant stress tolerance, nutrient uptake, and overall health, making them essential for sustainable agriculture. Their multifaceted contributions to the rhizosphere—through biofertilization, bioprotection, and biostimulation—have led to growing interest in their application. In recent years, in vitro mycorrhization has emerged as a promising approach for the rapid propagation of economically and ecologically important plant species, offering improved agronomic and physiological traits as well as increased resilience to environmental stressors. However, challenges remain in achieving consistent AMF-plant symbiosis under in vitro conditions across diverse species. This review highlights the potential of in vitro mycorrhization as a controlled system for investigating AMF interactions and their impact on plant development. Various in vitro mycorrhization systems are described and discussed, along with their applications in the mass production of AMF propagules and mycorrhizal plants, and their role in enhancing the acclimatization of micropropagated plantlets to ex vitro conditions. The role of in vitro mycorrhization as an effective tissue culture approach that integrates plant propagation with enhanced resilience to environmental stress is emphasized. The factors influencing the success of in vitro mycorrhization and strategies for the large-scale production of AMF propagules and mycorrhizal plants are explored. Although research in this area is still limited, existing studies underscore the potential of in vitro mycorrhization to enhance plant tolerance to abiotic and biotic stresses—an increasingly urgent goal in the context of climate change and global food security. Full article

Compost teas (CTs) can be considered natural microbial consortia, able to enhance biostimulation and defense in crops. This study focuses on two plant-derived CTs and their potential use as eco-friendly biofertilizers for chickpeas and peas, with the broader aim to protect soil fertility. Our experiments demonstrated that the two CTs have biostimulatory or inhibitory effects depending on dilution, target plant species, CT microbial load and metabolism, and age of CT preparation. Peas exhibited positive responses to treatments, while chickpeas could be negatively affected depending on CT concentration. The CT microbial load positively affected biostimulation for both plant species. The metabolic profiles of the CT-associated microbial communities were evaluated using the Biolog EcoPlate™ system. Spearman’s correlation analysis allowed us to ascertain a positive interaction between root elongation and the microbial consumption of specific substrates, namely polymers, erythritol, and L-serine. On the contrary, phenolic compound consumption showed a negative correlation. In chickpeas, root and collar necrosis, estimated with the McKinney index, increased after treatment with CTs at the highest concentration, confirming a phytotoxic effect; but diagnostic analyses demonstrated that the necrosis was also partially attributed to pathogenic Fusarium spp. On the other hand, proper dilutions of treatments determined a decrease in necrosis severity, indicating putative CT biocontrol properties. Full article