Sakei Research Articles

Beneficial Role of Heat-Treated Lactobacillus sakei HS-1 on Growth Performance, Nutritional Status and Gut Microbiota in Weaned Piglets.

In the swine industry, there is a strong need to replace an antibiotic growth promoter (AGP) used as feed additives in weaned piglets to enhance nutrient utilization in their diets and improve growth performance. Lactobacillus sakei HS-1 strain is a microbial preparation isolated from pickles. The study aim is to investigate the effectiveness of heat-treated L. sakei HS-1 strain (HT-LS) as a growth promoter in weaned piglets compared to colistin (CS), a widely used AGP. Eighteen crossbred weaned piglets (Landrace × Yorkshire × Duroc) of 21 days (average body weight [BW]: 7.06 ± 0.59 kg) were divided into three groups: fed the control diet (CT group), fed a diet supplemented with 30 ppm colistin sulphate (CS group), fed a diet supplemented with HT-LS at a concentration of 2.0 × 105 cells/g (LS group) until 49 days. The results indicated that LS group exhibited significantly higher average daily gain (p < 0.05) and higher BW (p < 0.1) compared with CT group, even higher than CS group. CS group showed higher growth performance compared to CT group but the differences were not statistically significant. In addition, LS group had higher (p < 0.05) or tended to higher (p < 0.1) concentrations of several plasma amino acids than the other two groups at 35 and 49 days. Faecal acetate concentration was higher (p < 0.1) in LS group than in CT group at 35 days. Blood immunoglobulin G concentration in LS group was significantly lower (p < 0.05) than in CT group at 35 and 49 days, and blood immunoglobulin A tended to be lower (p < 0.1) at 35 days than in CT group. LS group showed an increased abundance of g_Prevotella 7, g_Streptococcus and g_Lactobacillus (linear discriminant analysis [LDA] score ≥ 2.0). Predictive metagenomic analysis revealed an enrichment of the mixed acid fermentation pathway (LDA score ≥ 2.0). Furthermore, several gut microbes exhibited correlations with plasma amino acids (p < 0.01) and short-chain fatty acids in faeces (p < 0.01). These findings demonstrate that HT-LS improves the growth performance of weaned piglets by enhancing the efficient utilization of nutrients through gut microbiota modification.

Evaluation of Lactobacillus Sakei Probiotic Supernatant’s Effectiveness in Promoting Apoptosis and Decreasing Breast Cancer MCF-7 Cancerous Cells through Modulation of Bax and Bcl2 Genes

Introduction: Accumulating evidence has revealed that inducing apoptosis is an important strategy to control excessive breast cancer cell proliferation. In this study, the supernatant effect of the probiotic strain of Lactobacillus Sakei on Expression Level of Apoptosis-Related Genes (Bax/Bcl2) in Breast Cancer Cell Line (MCF-7) was investigated. Methods: In the experimental study, MCF-7 breast cancer cells were cultured in DMEM medium with 10% bovine serum. The cells were treated in 1, 2, 3, 4 and 5 mg/ml concentrations of sakei supernatant and incubated at 24, 48 and 72 hours. The MTT assay was used to measure cytotoxicity effect according to kit manufacturer's protocol in all three incubation times. MCF-7 cells with concentration of sakei supernatant at IC50 point (5 mg / ml) to examine the expression of genes Bax and Bcl2 were incubated for 72 hours. Real-Time PCR was performed to analyze the changes in the expression of Bax and Bcl2 genes. Results: The results of this study indicated that bioavailability of MCF-7 cell line reached the lowest value at concentration of 5 mg/ml compared to the control group. In addition, MCF-7 cell line treatment with Lactobacillus sakei supernatant at a dose of 5 mg/ml and 72 h incubation time, showed significantly increased expression of BAX (p-value= 0.0033) and significantly decreased expression of BCL-2 (p-value= 0.0278). Conclusion: The results indicate that Lactobacillus sakei supernatant can reduce the bioavailability of breast cancer cells by inducing apoptosis pathway.

Prebiotic activity of enzymatically modified pea peel dietary fiber: An in vitro study

The study examined the prebiotic index of enzymatically modified insoluble dietary fiber from pea peel by using three probiotic bacterias; Lactobacillus rhamnosus ATCC 7469, Lactobacillus sakei ATCC 15521, Lactobacillus plantarum ATCC 8014 and one pathogenic bacteria; Escherichia coli ATCC 4157. A positive value for prebiotic potential was determined which was greater than inulin, unmodified dietary fiber, and standard glucose. The 30 h of cultivation, the cell density obtained from Lactobacillus rhamnosus ATCC 7469 culture conducted in MRS was 7.45 ± 0.08 log CFU/mL in glucose medium and 7.37 ± 0.07 log CFU/mL in dietary fiber medium. Growth kinetics analysis showed a positive effect for Lactobacillus spp. in DF medium. DF could boost cell biomass and relative growth rate of probiotic bacteria. Thus, the microbiome of the colon facilitates dietary fiber fermentation by bacteria shown in in vitro simulated gastrointestinal model.

Farsi gum (zedo gum) coating incorporated with Lactobacillus sakei; a novel shelf-life extension for Turkey breast during refrigerated storage

Antioxidant and antibacterial coatings incorporated with biological agents are an emerging alternative for preserving meat products. In this study, Farsi gum-based coatings (FG) incorporated with Latilactobacillus sakei were used for the shelf-life extension of refrigerated turkey breast. The quality and safety properties of coated turkey breast were investigated during storage at refrigeration temperature. Results revealed that L. sakei loading into the FG coating could significantly (p < 0.05) improve the quality of turkey breast in a 16-day refrigerated storage. The increase in the values of pH (6.15–6.94), total volatile basic-nitrogen (TVB-N) (34.33–43.13 mg N/100 g), thiobarbituric acid reactive substances (TBARs) (2.27–3.67 mg MDA/kg), and protein carbonyl (PC) (1.62–2.14 nmol/mg protein) of samples during cold storage periods was as follows: FG 2% + L. Sakei < FG 1% + L. Sakei < FG 2% < FG 1% < uncoated (control). The microbial quality of turkey breast showed a significant (p < 0.05) improvement in the presence of the L. sakei coatings, ranging from 7.15 to 7.75 log10 CFU/g in different treatments. The texture, odor, color, and overall acceptability of the coated turkey breast samples were significantly (p < 0.05) more desirable than the uncoated turkey breast samples. The findings revealed that FG coating incorporated with L.sakei can improve turkey breast's shelf-life by reducing microbial growth and adverse chemical reactions.

Efficacy of lyophilized Lactobacillus sakei as a potential candidate for preventing carbapenem-resistant Klebsiella infection

BackgroundAntimicrobial resistance is considered one of the greatest threats to human health, according to the World Health Organization (WHO). Gram-negative bacteria, especially carbapenem-resistant Enterobacteriaceae (CRE), have become a significant concern in antimicrobial-resistant bacteria’s global emergence and spread. Among CRE pathogens, carbapenem-resistant Klebsiella pneumoniae (CRKP) has recently been reported as a highly infectious strain associated with high mortality and morbidity in adults and immunocompromised patients. Additionally, CRKP-related infections are challenging to treat, as carbapenems are the last resort of antibiotics. Therefore, developing novel drugs with different mechanisms of action from existing drugs is urgently required to defeat this lethal menace. Under such circumstances, probiotics can be therapeutic candidates for inhibiting pathogens. Thus, our research team has been focusing on probiotics for a long time to develop potential anti-CRKP drug agents.MethodsAfter extensive efforts, we finally found a novel probiotic strain, Lactobacillus sakei PMC104, suitable for treating CRKP infection. It was isolated from kimchi. As part of our expansion into therapeutic development, we evaluated the L. sakei strain effect against CRKP pathogens in both in vitro and in vivo experiments. Moreover, we conducted media optimization at food grade and then established a scale-up process on a pilot scale. Subsequently, a lyophilizate was obtained and used in a mouse model infected with CRKP.ResultsData demonstrated that the L. sakei strain has an inhibitory effect against CRKP infection both in in vitro and in vivo experiments and also increases the level of short-chain fatty acids in the feces of mice after receiving L. sakei strain treatment for 10 days. Furthermore, treatment with L. sakei powder remarkably diminished body weight loss, mortality, and illness severity in CRKP-infected mice, showing a preventive effect of our PMC 104 against CRKP infection.DiscussionOur results demonstrate the potential therapeutic effect of our candidate probiotic strain against CRKP, suggesting that L. sakei PMC 104 could be considered an antimicrobial candidate for treating CRKP infections. However, extensive studies, including additional toxicity tests and clinical trials, are still essential to develop it as a new anti-CRKP therapeutic agent.

Cu(OH)2 nanowire arrays@Cu Foam for high–sensitivity nonenzymatical electroanalysis of histamine: Exploration of electron transfer kinetics and determination of histamine levels in Lactobacillus sakei subsp. sakei–inoculated fermented mandarin fish

Presently, Cu(OH)2 nanowire arrays@Cu Foam (Cu(OH)2–NWA@Cu Foam) nanostructure has been confirmed to possess an excellent capacity of nonenzymatical electroanalysis of histamine (His). Based on Cu(OH)2–NWA@Cu Foam electrode, electrochemical investigations elucidated electron transfer kinetics principles of electrooxidation of His. Substantially, it was realized that a four–electron–transferring dehydrogenation was involved in diffusion–controlled electrooxidation of His, contributing tremendously to establishing as–proposed mechanization of His electrooxidation. At optimal conditions, Cu(OH)2–NWA@Cu Foam electrode reflected excellent electrochemical performance such as sensitivity of 3.089 mA mM–1 cm–2, limit of determination of 94 nM, respond time of 1.6 s and linear respond rang of 0.5–1250 μM. The outperformed electroanalytical performance can be physically explicated by the dedications from larger exposed surface area, bigger interface–hydrophilicity–deduced His diffusion coefficient and less charge transfer resistance. Moreover, the outstanding selectivity, stability and reproducibility of Cu(OH)2–NWA@Cu Foam electrode ensured its practical effectiveness in regulating real His levels in fermented mandarin fish. Compared with control group, the mandarin fish by inoculating Lactobacillus sakei subsp. sakei delivered less His contents, deducing that inoculation of Lactobacillus sakei subsp. sakei can effectively depress His generation during fermentation process. Eventually, the one–step as–established Cu(OH)2–NWA@Cu Foam nanostructure positioned itself as an upcoming possibility to pursue commercialized utilization.

Identification of amine-producing bacterium (APB) in Chinese fermented mandarin fish (Chouguiyu) by high-throughput sequencing and culture-dependent methods

Identifying the main amine-producing bacteria (APB) in fermented foods is the key to controlling the biogenic amines (BAs) content. This study investigated the BAs contents and bacterial profiles in fourteen Chinese fermented mandarin fish (Chouguiyu). The orthogonal partial least squares-discriminant analysis was used to explore the potential relationship between bacteria and BAs profiles. Identification of unclassified APB and verification of amine-producing capacity by the culture-dependent method. The results show that the total BA contents of Chouguiyu were in the range of 81.9–860 mg/kg-1. The predominant BAs in Chouguiyu were putrescine, cadaverine, histamine and tyramine. Three bacterial species (Lactobacillus sakei, unclassified Enterobacteriaceae, Morganella psychrotolerans) were closely related to BAs production. The nucleotide sequence comparison showed that Citrobacter sp. was 100 % identical to the unclassified Enterobacteriaceae.

Efficacy of Probiotic Strains Lactobacillus sakei Probio65 and Lactobacillus plantarum Probio-093 in Management of Obesity: An In Vitro and In Vivo Analysis.

The prevalence of obesity, characterized by an excessive accumulation of adipose tissue and adipocyte hypertrophy, presents a major public health challenge. This study investigates the therapeutic potential of two probiotic strains, Lactobacillus sakei Probio65 and Lactobacillus plantarum Probio-093, in the context of obesity. Utilizing 3T3-L1 cell-derived human adipocytes, we assessed Probio65's and Probio-093's capacity to mitigate triglyceride accumulation and influence adipocytokine production in vitro. Subsequently, an in vivo trial with male C57BL/6J mice examined the effects of both probiotic strains on adipose tissue characteristics, body weight, fat mass, and obesity-related gene expression. This study employed both live and ethanol-extracted bacterial cells. The results demonstrated significant reductions in the triglyceride deposition, body weight, and adipose tissue mass in the treated groups (p < 0.05). Furthermore, both strains modulated adipokine profiles by downregulating proinflammatory markers such as PAI-1, leptin, TNF-α, STAMP2, F4/80, resistin, and MCP-1, and upregulating the insulin-sensitive transporter GLUT4 and the anti-inflammatory adiponectin (p < 0.05). Our findings suggest that Lactobacillus sakei Probio65 and Lactobacillus plantarum Probio-093 are promising agents for microbiome-targeted anti-obesity therapies, offering the effective mitigation of obesity and improvement in adipocyte function in a murine model.

Quality and safety of pork meat after cooling and treatment with lactic starters

Cooling the pork half-carcasses in a refrigerating chamber with showering had no significant impact on their surface temperature. Still, it reduced the core temperature of the meat in 1 hour after cooling compared with air-cooling. pH-value of all pork half-carcasses that were subjected to cooling with the showering method, as well as the final processing of the pork with suspensions of Lactobacillus sakei and Leuconostoc carnosum in 1 hour and on the 4th day of storage in a chilled condition was within the limits typical for fresh and high-quality meat. The greatest weight loss of the pork half-carcasses occurred during the first 24 hours when they were being cooled. The weight loss of the pork half-carcasses in a chilled condition during 1 day when they were being cooled in a refrigerating chamber without the use of showering was 2.27%, when they were being cooled with the use of showering – 1.65%, when they were being cooled with the use of showering and final processing with SafePro® В-SF-43 (Leuconostoc carnosum) – 1.61% and SafePro® В-2 (Lactobacillus sakei) – 1.25% in comparison with the output of a hot carcass. Microorganism cultures of strains SafePro® B-SF-43 and SafePro® B-2, when they are applied at a dose of 106/cm2, had contributed to a colonization of the meat with the lactic-acid microorganisms and a significant decrease in the number of QMAFAnM in the neck and spine areas in 1 hour after cooling. S. aureus, Salmonella spp., and L. monocytogenes were not detected in the meat of the pork half-carcasses in all processing options during 4 days of storage in a chilled condition.

Investigation of Polyvinyl Alcohol (PVA)-Sakacin P Interaction by Molecular Docking Method

Aim: Group IIA bacteriocins, which contain unmodified amino acids and have antimicrobial activity, are a very broad group. Sakacins in this group are bacteriocins produced by Lactobacillus sakei. The most well-known sakacins are Sakacin A, G, K, P, and Q. In particular, Sakacin A and P are well characterized. This study aims to examine the interaction between a single monomer of PVA polymer and Sakacin P bacteriocin. Method: In t this study, the interaction of a single monomer of PVA polymer, which is among the water-soluble, biocompatible synthetic polymers, and Sakacin P bacteriocin, which has a protein structure, was investigated by molecular docking method. Results: As a result of our molecular docking study, the presence of binding affinity between the C2H4O monomer of PVA selected as the ligand and the Sakacin P protein selected as the receptor was determined. Conclusion: According to the results of the analysis, the presence of a strong inhibitor was detected between the ligand and the target. Therefore, this study can serve as a template for polymer-bacteriocin materials to be produced in the laboratory.

Influence of Different Starter Cultures on Physical–Chemical, Microbiological, and Sensory Characteristics of Typical Italian Dry-Cured “Salame Napoli”

The selection of starter cultures with different technological profiles and suitable microclimatic conditions is among the main tools used to improve the technological quality and safety of dry-cured salami. The aim of this study is to evaluate the effect of two different starter cultures [fast (SR) and medium (SM) acidification] during the process and on the quality of typical Italian dry-cured “Salame Napoli”. The ripening process was evaluated in dry-cured salami made with different cultures: Euroferment Medium (Staphylococcus xylosus, Lactobacillus plantarum) in SM and Euroferment Rapid (Staphylococcus carnosus, Staphylococcus xylosus, Lactobacillus sakei) in SR. The salami was stuffed in artificial casings, dried for 5 days and then ripened for 28 days at a controlled temperature of 12–14 °C and 80–90% RH. During the ripening process, an evaluation of the appearance, the pH, and the weight loss of the salami were conducted. For each finished product, the physical–chemical, microbiological, rheological, and sensory characteristics were evaluated. The results showed that the different starter cultures influenced the pH descent, which was faster in SR, reaching a pH value of 4.80 in three days. This influenced the consistency profile of the SR salami, which showed higher hardness (46.04 ± 6.53 in SR vs. 35.60 ± 2.62 in SM; p &lt; 0.05) and gumminess (19.21 ± 3.44 in SR vs. 11.89 ± 0.71 in SM; p &lt; 0.05) values. SR salami revealed a higher count of yeasts and a lower malondialdehyde concentration than SM. The presence of the starter in SM has positively affected the intensity of the aroma. The outcomes indicated the importance of selecting starter cultures to not only ensure food safety but also to obtain the desired sensorial characteristics of the product.

Adjunctive administration of parabiotic Lactobacillus sakei CVL-001 ameliorates drug-induced toxicity and pulmonary inflammation during antibiotic treatment for tuberculosis

Tuberculosis (TB) treatment requires a long therapeutic duration and induces adverse effects such as hepatotoxicity, causing discontinuation of treatment. Reduced adherence to TB medications elevates the risk of recurrence and the development of drug resistance. Additionally, severe cavitary TB with a high burden of Mycobacterium tuberculosis (Mtb) and inflammation-mediated tissue damage may need an extended treatment duration, resulting in a higher tendency of drug-induced toxicity. We previously reported that the administration of Lactobacillus sakei CVL-001 (L. sakei CVL-001) regulates inflammation and improves mucosal barrier function in a murine colitis model. Since accumulating evidence has reported the functional roles of probiotics in drug-induced liver injury and pulmonary inflammation, we employed a parabiotic form of the L. sakei CVL-001 to investigate whether this supplement may provide beneficial effects on the reduction in drug-induced liver damage and pulmonary inflammation during chemotherapy. Intriguingly, L. sakei CVL-001 administration slightly reduced Mtb burden without affecting lung inflammation and weight loss in both Mtb-resistant and -susceptible mice. Moreover, L. sakei CVL-001 decreased T cell-mediated inflammatory responses and increased regulatory T cells along with an elevated antigen-specific IL-10 production, suggesting that this parabiotic may restrain excessive inflammation during antibiotic treatment. Furthermore, the parabiotic intervention significantly reduced levels of alanine aminotransferase, an indicator of hepatotoxicity, and cell death in liver tissues. Collectively, our data suggest that L. sakei CVL-001 administration has the potential to be an adjunctive therapy by reducing pulmonary inflammation and liver damage during anti-TB drug treatment and may benefit adherence to TB medication in lengthy treatment.

Bacteria-antagonists of the agents of soryz bacterial diseases

Aim. To isolate and identify bacteria with antagonist properties for biocontrol of the agents of bacterial diseases of soryz (Sorghum oryzoidum) and sorghum crops. Methods. The studies were conducted in 2021-2023. Spore-forming bacteria were isolated from the soryz samples, collected in the fields of the experimental farm of the Uman National Horticulture University (Cherkasy region, Uman). Lactic acid bacteria were isolated from soryz plants, collected in the private land plot, located between the villages of Teolyn, Vladyslavchyk, Kniazhyky in Monastyryshche com- munity, Uman district, where Pershotravneve hamlet used to be situated. A total of 1,250 samples were analyzed. The experiment had three repeats. Spore-forming and lactic acid bacteria were isolated from the surface of soryz plants on the firm ripe stage in summer while isolating phytopathogenic bacteria. The isolates of lactic acid bacteria- antagonists were also isolated from the inner part of winter stubble stalk of soryz, collected from the tilled field. The antagonistic activity of the strains of lactic acid bacteria and spore-forming bacteria, isolated from different ecological niches, to phytopathogens of soryz and sorghum crops was determined in vitro. The strains of Pseudomonas syringae, the agents of soryz bacterial spots, were used as test-cultures: 211141a, 211141, 210341, 21034, and 210521, along with the collection strains of phytopathogens: Pseudomonas syringae 8299, Pseudomonas syringae subsp. syringae UKM B-1021, X. oryzae 8375, Dickeya chrysanthemi 8683, Diskeya chryzanthemi 8683. The antagonistic activity of the extracted isolates of spore-forming and lactic acid bacteria was studied using the method of radial strokes (joint cultivation of the antagonist and the strains under investigation). The bacterial isolates were deemed inactive if the growth delay zone was 0–5 mm (–), from 5 to 10 mm (+) – low activity, 11–20 mm (++) – moderate activity, over 20 mm (+++) – high activity regarding the test-cultures. To check the effect of the isolate-antagonist of phytopathogenic bacteria, artificial infecting was conducted in the field conditions. For this purpose, a diurnal culture of the antagonist was introduced into the stalk of plants in the concentration of 1×108 colony-forming units, and 24 h later, a culture of test-strain of the phytopathogen was administered above the previous puncture. The results were evaluated 7–14 days after the artificial infection. The experiment had three repeats. The isolates of bacteria which demonstrated their an- tagonistic properties regarding the phytopathogenic bacteria were identified by their morphological properties, Gram staining, catalase test, profile of carbohydrate fermentation and mass-spectrometry (MALDI-TOF – Matrix Assisted Laser Desorption/Ionization) using VITEK MS mass-spectrometer. Results. Thirty-eight spore-forming bacterial iso- lates were extracted from soryz; among these, 21030, 21095, 21040, ASV1, ASV3, B4 demonstrated their antagonistic activity towards the investigated phytopathogenic bacteria. Isolate 21040 showed high antagonistic activity to most test-strains of P. syringae from soryz (the zone of negative culture – 23–30 mm) and lower activity regarding the collection cultures. Isolates B4 and AVS3 demonstrated their selective activity regarding the investigated phytopatho- gens. Twenty isolates of lactic acid bacteria were extracted. Higher antagonistic activity was noted for the isolates of lactic acid bacteria 8/1 and F1 to the strains of P. syringae, isolated from soryz and collection cultures. The highest antagonistic activity of isolate 8/1 was noted regarding test-strains of P. syringae 210521 and X. oryzae 8375 (the zone of negative culture – 40–35 mm). In the field conditions, the treatment of sorghum plants with F1 affected the pathological process that developed due to the impact of the phytopathogenic bacteria P. syringae, which led to the reduction in disease symptoms. The taxonomic position of the isolates of bacteria, which seem to be promising for the control of disease agents, was determined. In terms of morphology of cells and colonies, the biochemical profile, and mass-spectrometry MALDI-TOF, the spore-forming isolates 21040 and B4 were identified as Bacillus subtilis, and ASV3 – as Bacillus vallismortis. The identified isolates of lactic acid bacteria were Lactobacillus pentosus F1 and Lactobacillus sakei 8/1. Conclusions. In addition to phytopathogenic bacteria, from soryz plants we isolated the strains of spore-forming bacteria Bacillus subtilis 21040, B4, Bacillus vallismortis AVS3 and such lactic acid bacteria as Lactiplantibacillus pentosus and Lactobacillus sakei 8/1 (Latilactobacillus sakei 8/1), promising for the elaboration of methods for the biocontrol of the agents of bacterial diseases.

Zein and tannic acid hybrid particles improving physical stability, controlled release properties, and antimicrobial activity of cinnamon essential oil loaded Pickering emulsions

Pickering emulsion loading essential oil has demonstrated a promising strategy as delivery system in food preservation, but localization in stability and antimicrobial activity limits application. In this study, Pickering emulsions co-loaded with tannic acid and cinnamon essential oil (ZTC) have been developed based on zein and tannic acid complexes (ZT) mediated interfacial engineering. Fourier transform infrared, fluorescence spectroscopy, and molecular docking results indicated tannic acid altered the structural of zein. Interfacial tension results indicated that tannic acid accelerated the adsorbed speed of zein particles by decreased interfacial tension (11.99–9.96 mN/m). ZT5 formed a viscoelastic and dense layer in oil–water interface than that for other ZTs, which improved stability and control release performance of ZTC. Furthermore, the ZTC showed an effective antimicrobial activity against spoilage organisms Pseudomonad paralactis MN10 and Lactobacillus sakei VMR17. These findings provide new insight for developing co-loaded multiple antimicrobial agents within Pickering emulsion as a delivery system.

Effect of lactic acid bacteria ferment cultures on pork freshness

During the primary pork processing at the stage of cooling half-carcasses, their mass is lost, leading to economic losses. One promising way to solve this problem is to wash halfcarcasses with chilled water. This requires decontaminating meat with microflora, which causes its spoilage. The purpose of the study is to determine the effectiveness of the final treatment of pork half-carcasses with ferment cultures of SafePro® B-SF-443 (Leuconostoc carnosum) and SafePro® B-2 (Lactobacillus sakei) strains for their bioconservation and preservation of freshness. The paper uses organoleptic, chemical, and microbiological research methods. It was established that cooling half-carcasses of pork in the refrigerator using cold water washing contributes to the appearance of signs of meat spoilage in terms of microbial contamination and pH value already on the 4th day of storage. Surface treatment of half-carcasses with suspensions of lactic acid microorganisms of SafePro® B-SF-43 (Leuconostoc carnosum) and SafePro® B-2 (Lactobacillus sakei) strains at a dose of 107 /cm2 provides proper organoleptic parameters and the pH value of pork up to 7 days of storage, which correspond to high-quality meat. Both ferment cultures of lactic acid microorganisms reduce microbial contamination of meat due to the number of mesophilic aerobic and facultative anaerobic microorganisms in paired carcasses by 1.25 and 0.65 lg CFU/cm2 and increase the number of lactic acid microorganisms by 3.47 and 3.43 lg CFU/cm2 accordingly, this allows extending the shelf life of meat in the chilled form to at least 7 days. The most suitable culture for the final processing of half-carcasses of pork, which are cooled in the refrigerator in combination with washing with chilled water, is the SafePro® B-2 (Lactobacillus sakei) strain. The results obtained are promising for improving the technology of primary pork processing at the cooling stage using ferment cultures of lactic acid microorganisms as natural preservatives, which will increase the shelf life of meat, considering its quality and safety

Retraction Note: Characterization of a new bacteriocin-like inhibitory peptide produced by Lactobacillus sakei B-RKM 0559.

Retraction Note: Characterization of a new bacteriocin-like inhibitory peptide produced by Lactobacillus sakei B-RKM 0559.

Characteristics of Lactic Acid Bacteria as Potential Probiotic Starters and Their Effects on the Quality of Fermented Sausages.

The aim of this study was to explore the potential of commercial lactic acid bacteria (LAB) as probiotic starters in fermented sausages. We initially investigated the growth activity, acid production capability, and tolerance to fermentation conditions of Lactobacillus sakei, Lactiplantibacillus plantarum, and Pediococcus pentosaceus. All three LAB strains proved viable as starters for fermented sausages. Subsequently, we explored their potential as probiotics based on their antibacterial and antioxidant capabilities. L. plantarum exhibited stronger inhibition against Escherichia coli and Staphylococcus aureus. All three strains displayed antioxidant abilities, with cell-free supernatants showing a higher antioxidant activity compared to intact cells and cell-free extracts. Moreover, the activities of superoxide dismutase, glutathione peroxidase, and catalase were stronger in the cell-free supernatant, cell-free extract, and intact cell, respectively. Finally, we individually and collectively inoculated these three LAB strains into sausages to investigate their impact on quality during the fermentation process. External starters significantly reduced pH, thiobarbituric acid reactive substances, and sodium nitrite levels. The improvements in color and texture had positive effects, with the L. plantarum inoculation achieving higher sensory scores. Overall, all three LAB strains show promise as probiotic fermentation starters in sausage production.

Hydroxylation of Fatty Acids by Lactic Acid Bacteria.

Hydroxy fatty acids (HFAs) are fatty acids with hydroxyl functional groups attached to the main chain. HFAs are used in widely diverse industrial applications, healthy functional foods, artificial food flavorings, and alcoholic beverages. A lactic acid bacterium (LAB), Lactobacillus sakei, hydroxylates oleic acid. Furthermore, the hydroxyl fatty acid was identified by GC-MS as 10-hydroxystearic acid. The Lactobacillus sakei hydroxylated more than 90% of the oleic acid in the medium at 15°C after 30-48h. The hydroxyl enzyme needs a coenzyme for an electron donor as NADPH. The enzyme is useful for assay with monitoring NADPH concentration used an A340 device. The hydroxylate fatty acids are converted by LAB lactonize aroma lactone from commercial yeast strains, which can be detected directly by scent. Commercial beer brewing yeast T-58 produced the highest concentration of aroma lactone from hydroxyl fatty acids. Furthermore, the aroma lactone is identified by GC-MS as gamma-dodecalactone. The ratio of conversion is 87%. These results suggest that the lactonization conversion system is useful to hydroxylate fatty acids for alcoholic beverages.

Effects of dietary feed supplementation with heat-treated Lactobacillus sakei HS-1 on the health status, blood parameters, and fecal microbes of Japanese Black calves before weaning.

Our previous research suggested that heat-killed Lactobacillus sakei HS-1 (HK-LS HS-1) is potentially beneficial for improving intestinal microbes and reducing the number of medical treatments. This study aimed to investigate the effect of HK-LS HS-1 as a supplement in milk replacers (MRs) on clinical health during the 1-month preweaning period. Eighteen female calves were randomly assigned to either a group receiving the HK-LS HS-1 supplement (n = 9) or a control group without it (n = 9). We then investigated the effect of including supplementary HK-LS HS-1; 0.2% in MRs twice daily at 09:00 and 16:00 on the health, serum biochemical parameters (measured using an automated biochemical analyzer), and fecal bacteriological changes of preweaning Japanese Black calves at the day of the start of supplementation (before HK-LS HS-1 supplementation; day 0), at weaning (day 30), and at 2 weeks (day 45) and 4 weeks (day 60) after weaning. During the supplementation period (0-30 days), (1) an increase (p = 0.023) was observed in albumin, and there was a tendency of increase in total cholesterol level in the HK-LS HS-1 group but not in the control group; (2) substantial differences were obtained after the weaning period (30-60 days), although no differences were observed from 0-30 days in both groups. The anti-Müllerian hormone (AMH) level was substantially increased after weaning in the control group. No differences were observed in the amounts of Coliform spp. and Staphylococcaceae spp. between the two groups; thus, HK-LS HS-1 supplementation had similar antibacterial effects. A significant reduction was observed in the time to weaning of the HK-LS HS-1 group in the field trial. Supplementation with HK-LS HS-1 from an early stage after birth to weaning is a cost-effective treatment to improve the growth rate of preweaning calves. However, supplementation during only preweaning periods appears to have no beneficial effects on preventing weaning stress, especially in terms of AMH levels.

Multifunctional effects of Lactobacillus sakei HEM 224 on the gastrointestinal tract and airway inflammation

Mucosal tissues serve as the first defense line and their commensal microbiota play a role in sustaining of host health. This study aimed to isolate and evaluate a putative probiotic strain on various mucosal regions. Lactobacillus sakei HEM 224 was isolated from traditional Korean kimchi and identified. In the safety assessment L. sakei HEM 224 showed negative results for hemolysis, biogenic amine production and transferable antibiotic resistance. The probiotic potential of strain HEM 224 in diverse mucosal areas was shown in two different models, viz. a murine model with colitis induced by dextran sulfate sodium (DSS) and an allergic airway inflammation model induced by ovalbumin (OVA). In the colitis model, oral administration of L. sakei HEM 224 improved colitis physiology with immunomodulation, enhancing barrier components and gut microbiota alteration. In the allergic airway inflammation model, the intranasal administration of the strain decreased type 2 inflammation and enhanced epithelial barrier integrity from the airways. These results demonstrate that L. sakei HEM 224 can ameliorate inflammatory conditions in both the gastrointestinal and respiratory tracts through the reinforcement of the epithelial barrier and immunomodulation.