Search Results (253)

In Italy, the apple cider market is experiencing significant growth, driven by numerous small-scale artisanal producers who combine local apple varieties with traditional processes to offer complex, and diverse products. However, artisanal production based on spontaneous fermentations often encounters challenges in qualitative reproducibility, particularly related to sensory issues (stability across different vintages and high turbidity of the product). In this context, a methodology has been developed to optimize the technological process of cider production at Contrada Contro in the Monti Sibillini (MC), in Marche region, Italy. The research focused on the isolation and selection of indigenous yeasts from frozen must prepared in the 2023 vintage. Following isolation and preliminary characterization, the indigenous yeasts were used to referment the still cider, followed by 7 months of bottle aging, and a second sampling point was conducted after 14 months of aging on lees. Destructive analyses using HPLC-DAD and GC-MS were conducted to evaluate polyphenols and volatile compounds, while non-destructive analyses with a 12-quartz microbalance electronic nose and near infrared (NIR) spectroscopy allowed for a quicker assessment of production techniques. Chromatographic analysis results showed that the sensory quality of refermented products was strongly influenced by the composition of the yeast strains used. All fermentations inoculated with selected yeasts exhibited lower turbidity compared to spontaneous fermentation. These findings indicate that the selection of indigenous yeasts for cider refermentation enables the production of a high-quality product, enriched with beneficial compounds and characterized by a strong terroir identity, underscoring the importance of microbiological terroir. Full article

This study aimed to isolate, characterize, and evaluate bacterial consortia capable of degrading the diamide insecticide cyantraniliprole in aqueous systems and to assess their bioremediation potential under environmentally relevant conditions. Four bacterial consortia, each comprising six isolates, demonstrated significant growth in mineral media containing cyantraniliprole as the sole carbon source, and the isolates were identified using conventional microbiological techniques in combination with MALDI-TOF-MS analysis. The bacterial consortia were enriched from pesticide-contaminated environments and systematically evaluated using microbiological, physiological, and analytical approaches to determine their degradation potential and environmental adaptability. The degradation performance of the consortia was systematically assessed under varying environmental parameters, including temperature, pH, salinity, and incubation time, with optimal degradation observed at 30–35 °C, pH 7.0–8.0, 0.5–5.0% NaCl, and 11 days of incubation at 150 rpm using an initial cyantraniliprole concentration of 50 mg/L. Biodegradation efficiency was further evaluated using DCPIP reduction assays, alongside measurements of biofilm formation and biomass production, indicating enhanced metabolic activity and adaptive responses under pesticide-induced stress. The consortia also exhibited the capacity to degrade structurally related diamide pesticides, including flubendiamide, chlorantraniliprole, cyclaniliprole, and fluchlordiniliprole, suggesting broad-spectrum biodegradation potential. Their performance was further validated in a simulated water microcosm system designed to mimic environmentally relevant contamination scenarios. In simulated contaminated water (60 mg/L cyantraniliprole), bacterial inoculants standardized to 10⁷ CFU/mL achieved substantial degradation after 20 days of incubation at 30 °C, as confirmed by HPLC analysis, with the six-strain consortium (T4), comprising Bacillus subtilis subsp. subtilis AZFS3, Bacillus pumilus AZFS5, Bacillus mojavensis AZFS15, Bacillus paramycoides AZFS18, Pseudomonas aeruginosa KZFS4, and Alcaligenes aquatilis KZFS11, demonstrating the highest removal efficiency (98.27%) and reducing the pesticide concentration to 1.00 mg/L, followed by consortium T3 (96.72%), which consisted of Bacillus subtilis Ht1, Bacillus subtilis Ht2, Bacillus mojavensis Ht3, Pseudomonas aeruginosa Ht4, Pseudomonas aeruginosa Ht5, and Pseudomonas aeruginosa Ht6. Residue analysis and predictive bioinformatic assessment further supported the biodegradation capacity of the selected bacterial communities and suggested the formation of simpler transformation products. Overall, the investigated bacterial consortia exhibited high degradation efficiency and environmental adaptability, highlighting their potential as effective and eco-friendly agents for the bioremediation of cyantraniliprole-contaminated water systems Full article

This study investigated the behavior of Salmonella Typhimurium ATCC 14028, Escherichia coli O157:H7 and Listeria monocytogenes ATCC 13932 during the ripening of ‘Nduja, a traditional spreadable fermented sausage for which quantitative microbiological data remain limited. An experimental challenge test was conducted under pilot-plant conditions simulating artisanal production, with products inoculated with the three pathogens and monitored over a 28-day ripening period. Microbiological analyses were performed at defined time points, alongside pH and water activity measurements, and inactivation kinetics were modelled using linear and non-linear approaches. The results showed a pathogen-dependent response to the combined antimicrobial hurdles of the process. Salmonella Typhimurium was declined to levels below the detection limit by day 28 (–7.10 log CFU/g), while E. coli O157:H7 showed a progressive reduction (–3.61 log CFU/g) but persisted at detectable levels. L. monocytogenes exhibited the highest resistance, with only a limited reduction (–1.32 log CFU/g); however, no net growth was observed throughout the ripening period, indicating that the product environment did not support its growth. The ripening process was characterized by decreasing pH and water activity, driven by lactic acid bacteria growth, with no differences between inoculated and control samples. Non-linear models provided the best fit to the survival data, highlighting the presence of resistant subpopulations. Overall, the results suggest that ‘Nduja ripening creates conditions unfavorable for sustained pathogen proliferation, although the extent of microbial reduction differed among the investigated microorganisms. These findings provide useful data for the microbiological characterization of this traditional product and may support future risk assessment and process validation studies. 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

Mining tailings limit plant establishment due to their low fertility and high heavy metal content. Arbuscular mycorrhizal fungi (AMF) can improve plant adaptation in these environments. This study evaluated the response of Festuca arundinacea, Brachiaria brizantha and Cynodon dactylon inoculated with endogenous and exogenous AMF under a tailing gradient (0, 50 and 100%) under controlled conditions. A 3 × 3 × 3 factorial design with sterilized substrate was used to isolate the effect of the inoculum. After 90 days, biomass, mycorrhizal colonization and sporulation were measured. The exogenous inoculum significantly increased biomass and colonization (>50%), particularly under high stress, while the endogenous inoculum showed a limited response (<40). Sporulation increased under extreme conditions, indicating an adaptive strategy of the AMF. These results demonstrate that mycorrhizal function depends on the type of inoculum and the microbiological context and highlight the potential of Festuca arundinacea with exogenous inoculum for establishing vegetation on mining waste. Full article

Understanding the interaction between plants and rhizosphere microorganisms is critical for the development of biofertilizers. Fluorescent labeling of rhizosphere microorganisms serves as a key strategy to track their behavior during plant–microbe coculture. However, most newly isolated strains are novel and lack available molecular tools for such studies. In this research, Planococcus dechangensis NEAU-ST10-9^T (P. dechangensis NEAU-ST10-9^T), a salt-tolerant strain, was obtained from the China General Microbiological Culture Collection Center (CGMCC). It significantly increased maize root length by approximately 1.56-fold. To investigate the underlying mechanism, a donor strain (Ec102) and a shuttle plasmid (pAS104) were engineered to mediate conjugation with P. dechangensis NEAU-ST10-9^T and drive GFP overexpression in the bacterium, generating the genetically labeled strain Pd103. The fluorescence intensity (expressed as GFP/OD₆₀₀, arbitrary units) of Pd103 increased with bacterial growth and was approximately tenfold higher than that of the wild-type strain after 16 h of culture. Following inoculation onto maize seeds, confocal microscopy analysis revealed that Pd103 colonized the epidermis and endodermis of maize roots. These results indicated that P. dechangensis NEAU-ST10-9^T could invade maize roots and promote maize seedling growth. In summary, we have successfully established a robust fluorescence labeling and tracking system tailored for P. dechangensis NEAU-ST10-9^T, which constitutes a valuable tool for elucidating the cellular and molecular mechanisms governing its plant–microbe interaction. Full article

Background/Objectives: Urine culture processing is labor-intensive and prone to operator-dependent variability. This study compared total laboratory automation (TLA; BD Kiestra™) with manual urine culture processing in terms of workflow efficiency, diagnostic performance, and operator variability. Methods: Three hundred midstream urine specimens were processed using manual and automated workflows, stratified by technologist experience (expert ≥10 years; non-expert <2 years) and shift. Metrics included setup time, cleanup time, and total staff time (TST). Colony-forming unit (CFU) recovery using 1 µL manual inoculation, 10 µL manual inoculation, and 10 µL TLA inoculation of 20 known positive specimens was compared. Diagnostic performance was assessed against the 1 µL manual reference using serially diluted specimens at a ≥10⁵ CFU/mL threshold. Results: TLA reduced the setup time from 10 min 10 s to 2 min 05 s for experts and from 13 min 37 s to 2 min 20 s for non-experts (79–83% reduction). TST decreased from 11 min 06 s to 2 min 30 s and from 14 min 37 s to 3 min 15 s, respectively (77–78% reduction). Cleanup time showed smaller reductions that did not reach statistical significance in the paired analysis. Manual processing showed greater operator-dependent variability, which TLA substantially reduced. CFU recovery was concordant in high-burden specimens, with method-dependent differences in routine diagnostic samples. Conclusions: TLA improves urine culture workflow efficiency, reduces operator-dependent variability, and shows concordant semi-quantitative performance compared to the standard manual reference within the limits of a proof-of-concept design, supporting its implementation to enhance consistency and throughput in clinical microbiology laboratories. Full article

Post-harvest diseases caused by phytopathogenic microorganisms generate significant economic losses, particularly in tomato crops affected by Alternaria solani. This study evaluated the effectiveness of cold plasma combined with a bioextract of Bacillus vallismortis as a biological strategy to extend tomato shelf life. In vitro antagonism assays were performed by confronting B. vallismortis against A. solani. Additionally, shelf-life tests were conducted on tomatoes treated with Bacillus cells and Bacillus cell-free bioextract (BCFB), followed by inoculation with A. solani spores, assessing incidence, severity, weight loss, and microbiological parameters over time. Subsequently, tomatoes were treated with cold plasma in combination with BCFB and reevaluated. Results showed significant antagonistic activity, with B. vallismortis and BCFB inhibiting A. solani by 75% and 50%, respectively. In untreated tomatoes, BCFB reduced disease incidence to 66.66% and severity to scale 2, compared to 100% incidence and scale 5 severity in controls. The combined treatment with cold plasma and BCFB showed the highest effectiveness, completely inhibiting A. solani (0% incidence, scale 0 severity), with tomatoes remaining healthy after 25 days. These findings demonstrate that cold plasma combined with B. vallismortis represents an effective and sustainable alternative for controlling post-harvest phytopathogens and extending tomato shelf life. Full article

Alternative protein sources are increasingly considered in poultry nutrition, and insect meals may represent a promising strategy for modifying the compositional profile of maize silage in the context of waterfowl feeding. This study evaluated maize silage supplemented with Hermetia illucens (BAHI) or Tenebrio molitor (BATM) meal as alternatives to urea (BAUR) as a nitrogen source, including variants with lauric acid (BALA) and with the lactic acid bacteria (LAB) inoculant alone (BA), focusing on nutritional composition, microbiological quality, and selected mycotoxins (MT). Maize forage treated with LAB was ensiled for 8 weeks in five variants, with three independent silage replicates per treatment, and the silages were analyzed for nutrients, energy value, amino acids, fatty acids, microbial and MT content. Insect meals increased crude protein compared with BA (64.94–67.32 vs. 49.73 g/kg dry matter, DM) and nearly doubled ether extract in BAHI (40.08 vs. 21.74 g/kg DM), while apparent metabolizable energy for poultry ranged from 8.55 to 9.87 MJ/kg DM (BAHI). Urea elevated crude protein content to 66.37 g/kg DM without improving the essential amino acid index. Microbial indicators did not differ among treatments. In the MT profile, lower deoxynivalenol concentrations were observed in BAUR, BAHI, and BATM, and lower fumonisin B1 concentrations were observed in BATM and BALA, while aflatoxins and ochratoxin A were not detected. Overall, the results indicate that low-level inclusion of insect meals in combination with LAB improved the compositional characteristics of maize silage, while no significant differences were detected in the monitored microbial counts and only selective changes were observed in the mycotoxin profile. Full article

The present study examined for the first time the effect of native yeasts on the fermentation of artisanal Spondias purpurea L., wine produced in Santa Elena, Ecuador. To achieve this goal, three inoculation strategies were compared: a mixed culture containing Saccharomyces cerevisiae and Candida spp. (CLX), commercial S. cerevisiae (CL), and a spontaneous fermentation without added inoculum (SL). Five yeast isolates were identified from the fermentations, four belonging to Candida spp. and one to Kloeckera spp., using microbiological and biochemical methods. The CLX treatment showed the greatest yeast proliferation on PDA plates (2.7 × 10⁶ CFU/mL) and yielded the highest levels of higher alcohols, while the CL treatment produced the highest ethanol (3.72% ABV) and glycerol content (0.46%). All treatments were free of total and fecal coliforms, and their pH values (2.49–2.56) satisfied the requirements of the current Ecuadorian standard for wine production NTE INEN 374. Residual glucose content was specifically quantified using an enzymatic colorimetric (GOD-POD) assay, confirming the dry character of the wines. Molecular analysis of the final preparation obtained from the variant corresponding to the spontaneous fermentation without inoculum (SL) confirmed the presence of Hanseniaspora spp. (Kloeckera spp.), Diutina rugosa (C. rugosa), C. zeylanoides and Pichia kudriavzevii, after the obtained PCR amplicons using ITS1 and ITS4 were subjected to a blast analysis. Sensory evaluation by panelists (n = 15) favored the CLX wine, particularly for aroma and flavor attributes. The final glucose content reached a low value of 0.28 g/L, indicative of an extremely dry wine, with almost no fermentable sugar. Due to the lack of information related to wines produced from Spondias purpurea L., this study could contribute to a better understanding of the biological behavior and biodiversity of the microorganisms present in this fermentation process. These findings will help to improve wine regionality production, supporting the potential application of native regional yeasts in Spondias purpurea L. wine biotechnology. Full article

Silage is a fundamental component of cattle feed, and its microbiological quality is critical for animal health and human safety. Improper ensiling conditions, such as oxygen exposure or inadequate acidification, can promote the growth of pathogens like Listeria monocytogenes, Clostridium botulinum, and Bacillus cereus. This study aimed to evaluate the microbial status of maize silages and identify pre-ensiling factors influencing its hygienic safety. Over a four-year period, 406 silage samples were collected from cattle farms across Poland. The research evaluated general hygiene indicators and screened for specific pathogens using standard culture methods, polymerase chain reaction toxotyping, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The impact of agricultural practices, including soil quality, organic fertilization, and microbial inoculation, was also analyzed. The analysis revealed that 32.1% of silages fell outside the reference pH range, indicating potential aerobic instability. While Salmonella and Campylobacter were not detected, Clostridium spp. were highly prevalent (81.0%), and C. perfringens was confirmed in 24.9% of samples. Listeria species occurred in 2.9% of silages, with L. innocua being the most frequent isolate. Statistical analysis showed that organic fertilization was significantly linked to specific C. perfringens toxotypes, though it did not increase the overall microbial burden. Conversely, microbial inoculation generally reduced the counts of several undesirable bacteria, although these differences were not statistically significant across all parameters. High pH values and significant contamination with Clostridium, B. cereus, and fungi remain critical challenges for silage safety. The results underscore the necessity for improved agricultural practices—specifically the minimization of soil and manure contamination during harvest—and the broader adoption of microbial inoculation to ensure the microbiological stability of fermented forage. Full article

Consumer interest in low-SO₂ white wines is increasing; however, such approaches may reduce compositional and sensory predictability. This study evaluates how three fermentation strategies—SO₂ addition and Saccharomyces cerevisiae ES181 inoculation (SO₂Sc), spontaneous fermentation (NoSO₂-Spont), and inoculation with S. cerevisiae ES181 without SO₂ addition (NoSO₂Sc)—shape the chemical profile, polyphenolic composition, colour, microbiological status, and sensory perception of ‘Solaris’ wines relative to the must (reference). A single batch of ‘Solaris’ must (one press run) was split into three variants and fermented under identical temperature conditions (12 ± 0.5 °C), followed by cool ageing and natural sedimentation prior to bottling. Basic oenological parameters, selected fermentation by-products, viable yeast counts, CIE Lab colour, targeted polyphenolics (phenolic acids, flavonols, flavan-3-ols, and stilbenes), PCA of by-products, and blind sensory evaluation were assessed. The NoSO₂-Spont variant showed reduced fermentation completeness (higher residual sugars and lower ethanol) and the highest volatile acidity, together with elevated glycerol and several higher alcohols, and received the lowest sensory ratings. The SO₂Sc variant yielded the most controlled outcome, with the lowest volatile acidity, the brightest colour (higher L*, lower b*), and the highest sensory acceptance. The NoSO₂Sc variant produced intermediate sensory scores and a higher total phenolic content; however, volatile acidity remained high and viable yeast counts were the greatest, indicating increased susceptibility to microbiological activity during extended pre-bottling handling. Overall, the SO₂Sc strategy provides the greatest chemical stability and sensory acceptance, whereas low-SO₂ regimes require a hurdle approach (oxygen control, residual sugar management, hygiene, and stabilisation) to limit spoilage development and post-bottling refermentation. Full article

Growing environmental and food security concerns have increased interest in circular strategies to valorize agri-food by-products. Sunflower-seed press cake (SSPC), a protein-rich residue from oil extraction, is largely underutilized despite its high nutritional and functional value. This study aimed to develop a fermented plant-based food prototype (PBFP) from SSPC using Lactococcus lactis B12 and Penicillium camemberti, evaluating microbiological safety, chemical characteristics, and sensory acceptability. A blend containing 40% SSPC and 60% water was autoclaved, inoculated, and ripened for 4 weeks under controlled temperatures. Microbial counts, pH evolution, free amino acids, biogenic amines, volatile organic compounds (VOCs), cyclopiazonic acid (CPA) content, and sensory attributes were evaluated using cultural techniques, HPLC, HS-SPME/GC-MS, LC–ESI–MS/MS (QTRAP 4000), and sensory evaluation. L. lactis efficiently acidified the matrix (pH ≈ 4.5–4.9), ensuring microbial food safety, with high LAB counts (~10⁹ CFU/g) and absence of pathogens (Listeria monocytogenes and Salmonella spp.) and hygienic markers < 2 log CFU/g (B. cereus, E. coli, and Enterobacteriaceae). Free amino acids decreased during fermentation, and no histamine or tyramine was detected. VOC analysis revealed diacetyl, acetoin, 2,3-butanediol, and 1-octen-3-ol, contributing to mild dairy-like notes. CPA was detected at 0.48 ng/g, well below levels reported in cheeses. Sensory evaluation showed no significant differences in overall intensity between inoculated and control blends, although qualitative descriptors indicated subtle changes in aroma and texture. These results demonstrate the feasibility of safely producing a fermented plant-based prototype from SSPC. Future studies should explore longer ripening times, additional microbial consortia, and strategies to enhance texture and aroma complexity. Full article

Hyperspectral (HS) analysis was used to measure the dynamics of Fusarium head blight (FHB) disease severity on panicles of three oat cultivars, ‘Husky’, ‘Ivory’, and ‘Lelde’, under greenhouse conditions. Inoculation with Fusarium spp. spore material was conducted (i) on the seeds and (ii) plants at the mid-flowering stage (BBCH 65). Disease development on oat panicles was assessed visually, and imaged with an HS camera from the end of the flowering stage (BBCH 69) to the early–middle ripe stage (BBCH 83–85). To verify that FHB symptoms were caused by Fusarium spp. pathogens, a microbiological test was performed. At the end of the trial, mycotoxin analysis of the kernels was conducted. The collected HS data from diseased and control plant panicles were used to estimate the head blight index (HBI). A Python-based software was developed to assess HBI at the pixel level. Both visual assessment and HS analysis confirmed statistically significant differences in disease severity between all treatment options. The highest disease severity results were obtained in the last disease assessment run (BBCH 83–85) for the inoculated head treatment. Microbiological test results confirmed that FHB symptoms in oat kernels were mostly caused by F. sporotrichioides. The correlation coefficient between the visually assessed FHB disease severity results and HS analysis results was 0.969. The correlation coefficient between T-2/HT-2 mycotoxins and HS disease severity results was 0.971, which suggests the potential for using HS analysis in field monitoring for mycotoxin content detection. Full article

Ready-to-eat (RTE) fresh salads are widely consumed for their convenience and nutritional value, but they could represent a relevant food safety concern, as they do not undergo a lethal heat treatment before consumption, and furthermore, they may support the growth of Listeria monocytogenes during refrigerated storage. In this study, the growth potential of L. monocytogenes was evaluated by standardised challenge tests in five commercially available RTE salads: crispy lettuce, baby lettuce, a baby lettuce–spicy mustard mix, and two mâche products from different producers. Three different batches for each product were inoculated with a three-strain cocktail of L. monocytogenes at a target level of approximately 2–3 log CFU/g and stored under conditions simulating reasonably foreseeable refrigerated storage (7 °C for approximately two-thirds of their shelf life, followed by 10 °C for the remaining one-third), in accordance with ISO 20976-1 and EURL L. monocytogenes guidelines. The growth potential (Δ) was calculated as the difference between the highest mean L. monocytogenes concentration observed during storage and the mean of the initial concentration at time zero, both in three replicate samples; Δmax was defined as the highest Δ value among the tested batches. Crispy lettuce, baby lettuce, and the mixed salad supported the growth of L. monocytogenes, with Δmax values of 2.33, 2.60, and 3.65 log CFU/g, respectively. In contrast, both mâche products showed Δmax values ≤ 0.5 log CFU/g, indicating an inability to support pathogen growth under the tested conditions. These results demonstrate that the growth potential of L. monocytogenes in RTE salads is strongly product-specific and likely influenced by intrinsic characteristics and background microbiota, as well as by storage temperature. The findings underline the importance of strict temperature control and product-specific risk assessment to ensure compliance with microbiological criteria throughout shelf life and to mitigate the risk of listeriosis associated with RTE salads. Full article