Our experimental results clearly showed that the presence of sublethal chlorine stress (350 ppm total chlorine) led to the activation of genes related to biofilm formation (csgD, agfA, adrA, and bapA) and quorum sensing (sdiA and luxS) in the planktonic phase of S. Enteritidis. Increased expression of these genes clearly illustrated that chlorine stress played a role in initiating the formation of biofilms in *S. Enteritidis*. The results from the initial attachment assay were consistent with this observation. At 37 degrees Celsius, after 48 hours of incubation, the chlorine-stressed biofilm cells demonstrated a significantly higher population compared to their non-stressed counterparts. S. Enteritidis ATCC 13076 and S. Enteritidis KL19 displayed distinct biofilm cell counts under chlorine stress. The counts were 693,048 and 749,057 log CFU/cm2, respectively, for chlorine-stressed cells, and 512,039 and 563,051 log CFU/cm2, respectively, for non-stressed cells. Measurements of eDNA, protein, and carbohydrate, the primary constituents of the biofilm, confirmed the observed findings. Subjected to sublethal chlorine stress beforehand, 48-hour biofilms contained a higher abundance of these components. While 48-hour biofilm cells did not exhibit upregulation of biofilm and quorum sensing genes, this implies the chlorine stress effect was diminished in subsequent Salmonella generations. These findings, taken together, point to the capacity of sub-lethal chlorine concentrations to stimulate the biofilm-generating potential of S. Enteritidis.

Heat-processed food products frequently harbor Anoxybacillus flavithermus and Bacillus licheniformis, two prominent spore-forming bacteria. A systematic investigation of the growth kinetics for A. flavithermus or B. licheniformis, according to our findings, is lacking at present. A. flavithermus and B. licheniformis growth patterns in broth solutions were analyzed, encompassing different temperatures and pH values within the current study. Cardinal models were utilized to predict the influence of the specified factors on growth rates. For A. flavithermus, the estimated cardinal parameters Tmin, Topt, and Tmax were 2870 ± 026, 6123 ± 016, and 7152 ± 032 °C, respectively; the corresponding pHmin and pH1/2 values were 552 ± 001 and 573 ± 001. In contrast, B. licheniformis exhibited estimated values of 1168 ± 003, 4805 ± 015, and 5714 ± 001 °C for Tmin, Topt, and Tmax, respectively, and pHmin and pH1/2 of 471 ± 001 and 5670 ± 008, respectively. The growth of these spoilers in a pea beverage at 62°C and 49°C was investigated, respectively, to allow for model adjustments related to this product. The adjusted models, when tested under static and dynamic conditions, displayed robust performance. 857% and 974% of predicted A. flavithermus and B. licheniformis populations, respectively, fell within the -10% to +10% relative error (RE) range. Useful tools for assessing the spoilage potential of heat-processed foods, encompassing plant-based milk alternatives, are available through the developed models.

High-oxygen modified atmosphere packaging (HiOx-MAP) conditions favor Pseudomonas fragi, making it a primary cause of meat spoilage. The present work assessed the influence of CO2 on *P. fragi* growth and the related spoilage of beef stored under the HiOx-MAP system. Beef, finely ground and subsequently incubated with P. fragi T1, a strain demonstrating the most prominent spoilage potential from the isolates examined, was maintained at 4°C for 14 days beneath either a CO2-enriched HiOx-MAP (TMAP; 50% O2/40% CO2/10% N2) or a conventional HiOx-MAP (CMAP; 50% O2/50% N2) atmosphere. Compared to CMAP, TMAP's oxygen management resulted in beef with greater a* values and a more stable meat color, attributed to lower P. fragi counts beginning on day one (P < 0.05). check details Analysis of TMAP samples revealed a statistically significant (P<0.05) decrease in both lipase and protease activity, observed at 14 and 6 days, respectively, when compared to CMAP samples. The substantial increase in pH and total volatile basic nitrogen content in CMAP beef during storage was deferred by the use of TMAP. check details TMAP's effect on lipid oxidation was substantial, leading to higher concentrations of hexanal and 23-octanedione than CMAP (P < 0.05). Remarkably, this TMAP beef still exhibited an acceptable odor quality, likely due to CO2 mitigating the microbial formation of 23-butanedione and ethyl 2-butenoate. The antibacterial action of CO2 against P. fragi in HiOx-MAP beef was comprehensively explored in this study.

Winemakers consider Brettanomyces bruxellensis a significant threat due to its negative influence on the organoleptic qualities of the final product. Repeated wine contamination in cellars over years highlights the persistence of certain properties, capable of enduring environmental conditions and enabling survival through bioadhesion. The research investigated the interplay of the material's physicochemical surface properties, their morphology, and their adhesion to stainless steel, across both synthetic and wine-based matrices. A selection of more than fifty strains, demonstrating the species' full spectrum of genetic diversity, was chosen for consideration. Microscopic investigations brought to light a considerable morphological variety among cells, with some genetic groups characterized by the presence of pseudohyphae. Examining the physical and chemical characteristics of the cellular surface exposes differing actions among the strains; most display a negative surface charge and hydrophilic tendencies, whereas the Beer 1 genetic group exhibits hydrophobic behavior. Bioadhesion capabilities were demonstrated by every strain on stainless steel samples, becoming apparent within three hours. The concentration of cells adhering varied significantly, from a low of 22 x 10^2 to a high of 76 x 10^6 cells per square centimeter. Finally, our study demonstrates a substantial degree of variation in bioadhesion properties, the preliminary phase in biofilm development, directly linked to the genetic group exhibiting the most significant bioadhesion capability, noticeably more prominent in the beer group.

The wine industry is increasingly employing Torulaspora delbrueckii in the alcoholic fermentation process of grape must. The combined impact of this yeast species on wine's organoleptic characteristics, in conjunction with its interaction with the lactic acid bacterium Oenococcus oeni, is a field deserving further exploration. Sixty yeast strain combinations were examined in this study: 3 Saccharomyces cerevisiae (Sc) strains, 4 Torulaspora delbrueckii (Td) strains used in sequential alcoholic fermentation (AF), and 4 Oenococcus oeni (Oo) strains during malolactic fermentation (MLF). A key objective was to analyze the positive or negative interactions of these strains, leading to the identification of the combination that would result in improved MLF performance. Furthermore, a synthesized grape must has been developed, ensuring the success of AF and allowing for the subsequent execution of MLF. In such conditions, the Sc-K1 strain proves unsuitable for MLF operations, contingent upon prior inoculation with Td-Prelude, Td-Viniferm, or Td-Zymaflore, invariably accompanied by the Oo-VP41 component. From the various trials conducted, it is evident that the combination of sequential AF treatment with Td-Prelude and Sc-QA23 or Sc-CLOS, and subsequent MLF treatment with Oo-VP41, demonstrated a positive impact from T. delbrueckii compared to the Sc-only inoculation, specifically a reduction in the time taken to consume L-malic acid. To conclude, the observed outcomes strongly suggest that the proper selection of yeast and lactic acid bacteria (LAB) strains, and their compatibility, is fundamental to successful wine fermentations. The study's findings also indicate a positive influence on MLF stemming from particular T. delbrueckii strains.

Food safety is significantly compromised by the acid tolerance response (ATR) acquired by Escherichia coli O157H7 (E. coli O157H7) from low pH levels encountered in contaminated beef during the processing procedure. An investigation into the development and molecular mechanisms of the tolerance response of E. coli O157H7 in a simulated beef processing environment involved evaluating the resistance of a wild-type (WT) strain and its corresponding phoP mutant to acid, heat, and osmotic pressure. Pre-adaptation of strains was carried out utilizing varied conditions of pH (5.4 and 7.0), temperature (37°C and 10°C), and culture mediums (meat extract and Luria-Bertani broth). Correspondingly, the study also investigated gene expression linked to stress response and virulence in both wild-type and phoP strains within the tested environmental parameters. E. coli O157H7 strains pre-adapted to acidic conditions displayed elevated resistance to acid and heat, though their resilience to osmotic pressures lessened. Besides, acid adaptation within a meat extract simulating a slaughterhouse setting increased the ATR, but prior adaptation at 10 degrees Celsius reduced the ATR. The study demonstrated a synergistic effect of mildly acidic conditions (pH 5.4) and the PhoP/PhoQ two-component system (TCS) on increasing acid and heat resistance in E. coli O157H7. Genes related to arginine and lysine metabolism, heat shock, and invasiveness exhibited enhanced expression, signifying the PhoP/PhoQ two-component system as a mediator of acid resistance and cross-protection under mild acidic conditions. Both acid adaptation and the inactivation of the phoP gene resulted in a diminished relative expression of the stx1 and stx2 genes, which are recognized as key pathogenic factors. Beef processing appears to facilitate the occurrence of ATR within the E. coli O157H7 strain, according to the current observations. check details Accordingly, the persistence of the tolerance response during the subsequent processing conditions increases the possibility of food safety issues. Through this investigation, a more complete foundation is established for the effective application of hurdle technology within beef processing.

Climate change fundamentally alters wine chemistry, predominantly through the pronounced decline in malic acid concentration found within grape berries. Wine acidity presents a challenge for wine professionals, necessitating the exploration of suitable physical and/or microbiological solutions.