RESUMEN
BACKGROUND: Studies have linked matrix metalloproteinases (MMPs) to both thoracic aortic aneurysm and abdominal aortic aneurysm (TAA and AAA). The precise MMPs entailed in this procedure, however, were still unknown. This study used a two-sample Mendelian randomization (MR) analysis to look into the causal relationship between MMPs and the risk of TAA and AAA. METHODS: Eight MMPs, including MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, MMP-10, MMP-12, and MMP-13, were found among people of European ancestry with accessible Genome-Wide Association Studies (GWAS). We employed the findings from Genome-Wide Association Studies (GWAS) for 8 MMPs, and TAA and AAA from the FinnGen consortiums (3,201 cases and 317,899 controls, respectively) were used in a two-sample MR analysis. The primary method of analysis for MR was the inverse variance weighted (IVW) method, along with analyses of heterogeneity and horizontal pleiotropy. 31 single-nucleotide polymorphisms connected to MMP were retrieved. RESULTS: IVW demonstrated a negative causal association between TAA and AAA and serum MMP-12 levels. The incidence of TAA decreased by 1.031% for every 1 ng/mL increase in serum MMP-12 [odds ratio (OR) = 0.897, 95% confidence interval (CI): 0.831-0.968, P = 0.005]. The incidence of AAA fell by 1.653% (OR = 0.835, 95% CI: 0.752-0.926, P = 0.001) for every 1 ng/mL increase in serum MMP-12. There was no horizontal pleiotropy or heterogeneity in the MR data (P > 0.05). CONCLUSIONS: The levels of TAA and AAA and serum MMP-12 are causally related. MMP-12 is a factor that reduces the risk of AAA and TTA. Our study suggested that MMP-12 level is causally associated with a decreased risk of TAA and AAA.
Asunto(s)
Aneurisma de la Aorta Abdominal , Aneurisma de la Aorta Torácica , Metaloproteinasas de la Matriz , Humanos , Aneurisma de la Aorta Abdominal/genética , Aneurisma de la Aorta Abdominal/enzimología , Aneurisma de la Aorta Abdominal/diagnóstico por imagen , Aneurisma de la Aorta Abdominal/sangre , Aneurisma de la Aorta Abdominal/epidemiología , Aneurisma de la Aorta Torácica/genética , Aneurisma de la Aorta Torácica/enzimología , Aneurisma de la Aorta Torácica/sangre , Aneurisma de la Aorta Torácica/diagnóstico por imagen , Aneurisma de la Aorta Torácica/epidemiología , Estudios de Casos y Controles , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Incidencia , Metaloproteinasa 12 de la Matriz/genética , Metaloproteinasa 12 de la Matriz/sangre , Metaloproteinasas de la Matriz/genética , Metaloproteinasas de la Matriz/sangre , Análisis de la Aleatorización Mendeliana , Fenotipo , Polimorfismo de Nucleótido Simple , Factores Protectores , Medición de Riesgo , Factores de RiesgoRESUMEN
Class IIa bacteriocins produced in lactic acid bacteria are short cationic peptides with antimicrobial activity. In the search for new biopreservation agents, class IIa bacteriocins are considered to be the best potential candidates, not only due to their large abundance but also because of their high biological activity and excellent thermal stability. However, regulated by the biosynthetic regulatory system, the natural class IIa bacteriocin yield is low, and the extraction process is complicated. The biotechnological production of class IIa bacteriocins in various cell factories has been attempted to improve this situation. In this review, we focus on the application of biotechnological routes for class IIa bacteriocin production. The drawbacks and improvements in the production of class IIa bacteriocins in various cell factories are discussed. Furthermore, we present the main challenge of class IIa bacteriocins, focusing on increasing their production by constructing suitable cell factories. Recombinant bacteriocins have made considerable progress from inclusion body formation, dissolved form and low antibacterial activity to yield recovery. The development of prospective cell factories for the biotechnological production of bacteriocins is still required, which may facilitate the application of bacteriocins in the food industry.
Asunto(s)
Bacteriocinas , Biotecnología , Bacteriocinas/biosíntesis , Biotecnología/métodos , Antibacterianos/biosíntesis , Antibacterianos/farmacología , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/biosíntesis , Lactobacillales/metabolismoRESUMEN
In recent years, the emerging concern regarding safety issues associated with live bacterial cells is enhancing the interest in using cell components and metabolites derived from microbiota. Therefore, the term "postbiotics" is increasingly found in food microbiology, food scientific and commercial products. Postbiotics is defined as non-viable microorganisms or their components that provide benefits to the host. Many in vivo and in vitro experiments have shown that beneficial microbiota-generated extracellular nanoparticles (NPs) confer unique health promoting functions to the intestinal local and systemic effects, which can be considered as a novel postbiotics. Meanwhile, the postbiotics-NPs is a protective complex, delivering bioactive components to reach distant tissues and organs at high concentrations. These properties demonstrate that postbiotics-NPs may contribute to the improvement of host health by regulating specific gut microbiota and physiological functions, while the exact mechanisms are not fully elucidated. This review highlights the current understanding of postbiotics-NPs functional properties and mechanisms of health benefits, especially focusing on the interactions in gut microbiota and host, functions in human health and potential applications in future functional food and biomedical fields.
Asunto(s)
Microbioma Gastrointestinal , Microbiota , Probióticos , Humanos , Microbiota/fisiología , Intestinos/microbiología , Alimentos Funcionales , Promoción de la SaludRESUMEN
Chondroitin sulfate (CS) is a well-known bioactive substance with multiple biological functions, which can be extracted from animal cartilage or bone. Sturgeon, the largest soft bone animal with ~20% cartilage content, is a great candidate for CS production. Our recent study confirmed the role of sturgeon chondroitin sulfate (SCS) in reducing colorectal cancer cell proliferation and tumor formation. Here, we further studied the effect of SCS on modulating gut microbiome structure in colorectal cancer bearing mice. In this study, the transplanted tumor mice model was constructed to demonstrate that SCS can effectively halt the growth of transplanted colorectal tumor cells. Next, we showed that SCS significantly altered the gut microbiome, such as the abundance of Lactobacillales, Gastranaerophilales, Ruminiclostridiun_5 and Ruminiclostridiun_6. According to linear discriminant analysis (LDA) and abundance map analysis of the microbial metabolic pathways, the changes in microbial abundance led to an increase of certain metabolites (e.g., Phe, Tyr, and Gly). Fecal metabolome results demonstrated that SCS can significantly reduce the amount of certain amino acids such as Phe, Pro, Ala, Tyr and Leu presented in the feces, suggesting that SCS might inhibit colorectal cancer growth by modulating the gut microbiome and altering the production of certain amino acids. Our results revealed the therapeutic potential of SCS to facilitate treatment of colorectal cancer. This study provides insights into the development of novel food-derived therapies for colorectal cancer.
Asunto(s)
Neoplasias Colorrectales , Microbioma Gastrointestinal , Aminoácidos/metabolismo , Animales , Sulfatos de Condroitina/química , Neoplasias Colorrectales/patología , Heces/química , Peces/metabolismo , Metaboloma , RatonesRESUMEN
BACKGROUND: Recent studies demonstrate that fish byproducts can be used as sources of bioactive peptides for functional foods. Sturgeon skin contains abundant proteins but it has commonly been discarded during sturgeon processing. The objective of the present work was to identify and characterize the bioactive peptides from protein hydrolysates of sturgeon skin. RESULTS: Sturgeon skin protein extract (SKPE) hydrolyzed by flavourzyme for 60 min exhibited high antioxidant activity, dipeptidyl peptidase IV (DPP-IV) and angiotensin converting enzyme (ACE) inhibitory activity. The sequences of peptides from flavourzyme hydrolysates were identified using high-performance liquid chromatography-tandem mass spectrometry. Gly-Asp-Arg-Gly-Glu-Ser-Gly-Pro-Ala (P1) showed the highest DPPH radical scavenging activity (DPPH IC50 = 1.93 mmol L-1 ). Gly-Pro-Ala-Gly-Glu-Arg-Gly-Glu-Gly-Gly-Pro-Arg (P11) (DPP-IV IC50 = 2.14 mmol L-1 ) and Ser-Pro-Gly-Pro-Asp-Gly-Lys-Thr-Gly-Pro-Arg (P12) (DPP-IV IC50 = 2.61 mmol L-1 ) exhibited the strongest DPP-IV inhibitory activity. Gly-Pro-Pro-Gly-Ala-Asp-Gly-Gln-Ala-Gly-Ala-Lys (P6) displayed the highest ACE inhibitory activity (ACE IC50 = 3.77 mmol L-1 ). The molecular docking analysis revealed that DPP-IV inhibition of P11 and P12 are mainly attributed to hydrogen bonds and hydrophobic interactions, whereas ACE inhibition of P6 is mainly attributed to strong hydrogen bonds. CONCLUSIONS: These results indicate that SKPE hydrolysates generated by flavourzyme are potential sources of bioactive peptides that could be used in the health food industry. © 2021 Society of Chemical Industry.
Asunto(s)
Productos Pesqueros , Péptidos , Hidrolisados de Proteína , Piel , Animales , Cromatografía Líquida de Alta Presión , Productos Pesqueros/análisis , Simulación del Acoplamiento Molecular , Péptidos/análisis , Péptidos/química , Hidrolisados de Proteína/análisis , Hidrolisados de Proteína/química , Proteínas , Piel/químicaRESUMEN
Food microbial contamination not only poses the problems of food insecurity and economic loss, but also contributes to food waste, which is another global environmental problem. Therefore, effective packaging is a compelling obstacle for shielding food items from outside contaminants and maintaining its quality. Traditionally, food is packaged with plastic that is rarely recyclable, negatively impacting the environment. Bio-based materials have attracted widespread attention for food packaging applications since they are biodegradable, renewable, and have a low carbon footprint. They provide a great opportunity to reduce the extensive use of fossil fuels and develop food packaging materials with good properties, addressing environmental problems and contributing significantly to sustainable development. Presently, the developments in food chemistry, technology, and biotechnology have allowed us to fine-tune new methodologies useful for addressing major safety and environmental concerns regarding packaging materials. This review presents a comprehensive overview of the development and potential for application of new bio-based materials from different sources in antimicrobial food packaging, including carbohydrate (polysaccharide)-based materials, protein-based materials, lipid-based materials, antibacterial agents, and bio-based composites, which can solve the issues of both environmental impact and prevent foodborne pathogens and spoilage microorganisms. In addition, future trends are discussed, as well as the antimicrobial compounds incorporated in packaging materials such as nanoparticles (NPs), nanofillers (NFs), and bio-nanocomposites.
Asunto(s)
Materiales Biocompatibles , Contaminación de Alimentos , Microbiología de Alimentos , Embalaje de Alimentos , Antiinfecciosos/química , Antiinfecciosos/farmacología , Materiales Biocompatibles/química , Biopolímeros/química , Fenómenos Químicos , Contaminación de Alimentos/prevención & control , Embalaje de Alimentos/métodos , Embalaje de Alimentos/tendencias , Conservación de Alimentos , Humanos , Nanocompuestos/químicaRESUMEN
Chondroitin sulfate (CS) is a food-derived bioactive substance with multiple biological functions, which exists in animal cartilage and/or bone. Sturgeon, a type of cartilaginous fish, is rich in CS. Our recent study demonstrated the effect of sturgeon chondroitin sulfate (SCS) on reducing colorectal cancer cell proliferation and tumor formation. However, the molecular mechanisms of its anticancer activity remain unknown. In this study, the cell proliferation assay and flow cytometric analysis were used to examine the cell viability and apoptosis of colon cancer cell HT-29 cells and normal colonic epithelial cell NCM460 cells. Transcriptomic and proteomic studies were used to identify the main targets of SCS. SCS showed little effect on the genes/proteins expression profile of NCM460 cells but more sensitive to HT-29, in which 188 genes and 10 proteins were differentially expressed after SCS treatment. Enrichment analysis of those genes/proteins showed that the majority of them are involved in DNA replication, cell cycle progression and apoptosis. Quantitative RT-PCR and Western blot were used to determine essential genes/proteins and networks targeted by SCS to exert inhibiting the development of colorectal cancer function. This study provided great insights into developing food-derived novel therapeutics for colorectal cancer treatment.
Asunto(s)
Biomarcadores de Tumor/metabolismo , Sulfatos de Condroitina/farmacología , Neoplasias Colorrectales/tratamiento farmacológico , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Redes Reguladoras de Genes , Proteoma/efectos de los fármacos , Transcriptoma/efectos de los fármacos , Animales , Apoptosis , Biomarcadores de Tumor/genética , Ciclo Celular , Proliferación Celular , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Peces/fisiología , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Biologically active, artificially synthesized two-peptide bacteriocin PlnEF was used to study its mode of action on sensitive bacteria Lactobacillus plantarum pl2. The data obtained showed that PlnEF induced membrane permeabilization, allowing for the efflux of electrolytes, which was evidenced by the increased extracellular conductivity, the dissipation of transmembrane electrical potential and pH gradient, and rapid intracellular ATP depletion after L. plantarum pl2 cells were treated with PlnEF for minutes. Laser confocal microscopy showed that PlnEF accumulated very quickly in L. plantarum pl2 cells and the accumulation of PlnEF caused damage to cell membrane. Scanning electron microscopy and transmission electron microscopy further showed that PlnEF induced morphological changes and structure disruption to L. plantarum pl2 cells, such as the formation of blebs, microspheres, membrane deformation and cell lysis. In summary, the data obtained show that PlnEF caused cell membrane damage to L. plantarum pl2 cells. Our study reveals the antimicrobial mechanism of two-peptide bacteriocin PlnEF against L. plantarum.
Asunto(s)
Bacteriocinas/farmacología , Membrana Celular/metabolismo , Lactobacillus plantarum/metabolismo , Potenciales de la Membrana/efectos de los fármacos , Fuerza Protón-Motriz/efectos de los fármacos , Bacteriocinas/química , Membrana Celular/químicaRESUMEN
Bacillomycin L, a natural iturinic lipopeptide produced by Bacillus amyloliquefaciens, is characterized by strong antifungal activity against a variety of agronomically important filamentous fungi including Rhizoctonia solani Kühn. To further understand its antifungal actions, proteomes were comparatively studied within R. solani hyphal cells treated with or without bacillomycin L. The results show that 39 proteins were alternatively expressed within cells in response to this lipopeptide, which are involved in stress response, carbohydrate, amino acid and nucleotide metabolism, cellular component organization, calcium homeostasis, protein degradation, RNA processing, gene transcription, and others, suggesting that, in addition to inducing cell membrane permeabilization, iturin exhibits antibiotic activities by targeting intracellular molecules. Based on these results, a model of action of bacillomycin L against R. solani hyphal cells was proposed. Our study provides new insight into the antibiotic mechanisms of iturins.
Asunto(s)
Proteínas Fúngicas/aislamiento & purificación , Fungicidas Industriales/farmacología , Hifa/efectos de los fármacos , Proteoma/aislamiento & purificación , Rhizoctonia/efectos de los fármacos , Bacillus amyloliquefaciens/química , Membrana Celular/efectos de los fármacos , Permeabilidad de la Membrana Celular/efectos de los fármacos , Electroforesis en Gel Bidimensional , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Fungicidas Industriales/aislamiento & purificación , Expresión Génica , Perfilación de la Expresión Génica , Ontología de Genes , Hifa/genética , Hifa/crecimiento & desarrollo , Hifa/metabolismo , Redes y Vías Metabólicas/efectos de los fármacos , Redes y Vías Metabólicas/genética , Viabilidad Microbiana/efectos de los fármacos , Anotación de Secuencia Molecular , Péptidos Cíclicos/aislamiento & purificación , Péptidos Cíclicos/farmacología , Proteoma/genética , Proteoma/metabolismo , Rhizoctonia/genética , Rhizoctonia/crecimiento & desarrollo , Rhizoctonia/metabolismo , Espectrometría de Masa por Láser de Matriz Asistida de Ionización DesorciónRESUMEN
Bacillomycin L, a natural iturinic lipopeptide produced by Bacillus amyloliquefaciens, is characterized by strong antifungal activities against a variety of agronomically important filamentous fungi including Rhizoctonia solani Kühn. Prior to this study, the role of membrane permeabilization in the antimicrobial activity of bacillomycin L against plant pathogenic fungi had not been investigated. To shed light on the mechanism of this antifungal activity, the permeabilization of R. solani hyphae by bacillomycin L was investigated and compared with that by amphotericin B, a polyene antibiotic which is thought to act primarily through membrane disruption. Our results derived from electron microscopy, various fluorescent techniques and gel retardation experiments revealed that the antifungal activity of bacillomycin L may be not solely a consequence of fungal membrane permeabilization, but related to the interaction of it with intracellular targets. Our findings provide more insights into the mode of action of bacillomycin L and other iturins, which could in turn help to develop new or improved antifungal formulations or result in novel strategies to prevent fungal spoilage.
Asunto(s)
Antibacterianos/química , Membrana Celular/química , Hifa/química , Rhizoctonia/química , Anfotericina B/química , Anfotericina B/farmacología , Antibacterianos/farmacología , Membrana Celular/efectos de los fármacos , Permeabilidad de la Membrana Celular , Relación Dosis-Respuesta a Droga , Ensayo de Cambio de Movilidad Electroforética , Hifa/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica , Péptidos Cíclicos/química , Péptidos Cíclicos/farmacología , Rhizoctonia/efectos de los fármacosRESUMEN
BACKGROUND: Sturgeon (Acipenser schrencki) were filleted, minced, vacuum-packed and stored at 4 °C. Minced sturgeon muscles were analysed for 10 days to determine biochemical [eight biogenic amines, ATP and breakdown products, K value, total volatile basic nitrogen (TVB-N) and pH], microbiological (total viable counts, Enterobacteriaceae, Psychrotrophs, Pseudomonas, Aeromonas, Vibrio, Lactobacillus and Brochothrix thermosphacta) changes and their relationships. RESULTS: The shelf-life of sturgeon was found to be 3-4 days according to microbiological assessment. At the end of the storage, Psychrotrophs, Enterobacteriaceae and Aeromonas became the dominant bacteria, reaching 7.85, 7.98 and 8.02 log cfu g(-1), respectively. Biogenic amines, hypoxanthine and the K value increased significantly (P < 0.05) during the storage. Putrescine and cadaverine was the dominant biogenic amines while tryptamine was not detected during the storage. In addition, putrescine, cadaverine and hypoxanthine were highly related to storage time and total viable counts (r(2), 0.876-0.962), indicating that they can be good biomarkers for quality assessment of vacuum-packed minced sturgeon stored at 4 °C. CONCLUSION: In this study, key biochemical and microbiological attributes were established to monitor the spoilage and shelf life of vacuum-packed sturgeon. These results could help to establish better cold storage management of minced sturgeon products under commercial conditions.
Asunto(s)
Aminas Biogénicas/análisis , Peces/microbiología , Conservación de Alimentos/métodos , Almacenamiento de Alimentos/métodos , Nitrógeno/metabolismo , Nucleótidos/metabolismo , Alimentos Marinos/análisis , Animales , Cadaverina/análisis , Frío , Seguridad de Productos para el Consumidor , Microbiología de Alimentos , Embalaje de Alimentos/métodos , Humanos , Concentración de Iones de Hidrógeno , Hipoxantina/análisis , Oxígeno , Putrescina/análisis , Alimentos Marinos/microbiología , VacioRESUMEN
Metallothionein is a cysteine-rich protein with a high metal content that is widely found in nature. In addition to heavy metal detoxification, metallothionein is well known as a potent antioxidant. The high sulfhydryl content of metallothionein confers excellent antioxidant activity, enabling it to effectively scavenge free radicals and mitigate oxidative stress damage. In addition, metallothionein can play a neuroprotective role by alleviating oxidative damage in nerve cells, have an anticancer effect by enhancing the ability of normal cells to resist unfavorable conditions through its antioxidant function, and reduce inflammation by scavenging reactive oxygen species. Due to its diverse biological functions, metallothionein has a broad potential for application in alleviating environmental heavy metal pollution, predicting and diagnosing diseases, and developing skin care products and health foods. This review summarizes the recent advances in the classification, structure, biological functions, and applications of metallothionein, focusing on its powerful antioxidant effects and related functions.
RESUMEN
Weizmannia coagulans is an important potential probiotic with dual characteristics of Bacillus and Lactobacillus. This study describes a novel Weizmannia coagulans PL-W with excellent antibacterial activity isolated from Mongolian traditional cheese, in which safety and probiotic potential were evaluated by complete genome sequencing. The crude bacteriocins of W. coagulans PL-W showed antibacterial activity against various foodborne pathogens, including Listeria monocytogenes CMCC 54,004, Bacillus cereus ATCC 14,579, and Staphylococcus aureus ATCC 25,923. Moreover, the crude bacteriocins have outstanding stability against pH, temperature, surfactants, and are sensitive to protease. The complete genome sequencing revealed W. coagulans PL-W consists of 3,666,052-base pair (bp) circular chromosomes with a GC content of 46.24% and 3485 protein-coding genes. It contains 84 tRNA, 10 23S rRNA, 10 16S rRNA, and 10 5S rRNA. In addition, no risk-related genes such as acquired antibiotic resistance genes, virulence, and pathogenic factors were identified, demonstrating that W. coagulans PL-W is safe to use. Furthermore, the presence of gene clusters involved in bacteriocin synthesis, adhesion-related genes, and genes contributing to acid and bile tolerance indicate that W. coagulans PL-W is a potential candidate probiotic. Thus, antimicrobial activity and genome characterization of W. coagulans PL-W demonstrate that it has extensive potential applications as a food protective culture.
RESUMEN
The demand for lactic acid and lactic acid-derived products in the food, pharmaceutical, and cosmetic industries is increasing year by year. In recent decades, the synthesis of lactic acid by microbials has gained much attention from scientists due to the superior optical purity of the product, its low production costs, and its higher production efficiency compared to chemical synthesis. Microbial fermentation involves the selection of feedstock, strains, and fermentation modes. Each step can potentially affect the yield and purity of the final product. Therefore, there are still many critical challenges in lactic acid production. The costs of feedstocks and energy; the inhibition of substrates and end-product; the sensitivity to the inhibitory compounds released during pretreatment; and the lower optical purity are the main obstacles hindering the fermentation of lactic acid. This review highlights the limitations and challenges of applying microbial fermentation in lactic acid production. In addition, corresponding solutions to these difficulties are summarized in order to provide some guidance for the industrial production of lactic acid.
RESUMEN
A newly isolated anti-Streptococcus suis bacteriocin-producing strain LPL1-5 was obtained from healthy unweaned piglets' fecal matter, and was designated as Lactobacillus pentosus LPL1-5 based on morphology, biochemical properties, and 16S rDNA sequencing analysis. The medium composition for enhanced bacteriocin production by L. pentosus LPL1-5 was optimized by statistical methodology. Yeast extract, K(2)HPO(4)·3H(2)O, and MnSO(4)·H(2)O were identified as significant components influencing pentocin LPL1-5 production using the Plackett-Burman method. Response surface methodology was applied for further optimization. The concentrations of medium components for enhanced pentocin LPL1-5 production were as follows (g/L): lactose 20.00, tryptone 10.00, beef extract 10.00, yeast extract 14.00, MnSO(4)·H(2)O 0.84, K(2)HPO(4)·3H(2)O 4.92, triammonium citrate 2.00, Na-acetate 5.00, MgSO(4)·7H(2)O 0.58, Tween 80 1.00. Under the optimized condition, a value of 3154.65 ± 27.93 IU/mL bacteriocin activity was achieved, which was 4.2-fold that of the original medium.
Asunto(s)
Antibacterianos/aislamiento & purificación , Bacteriocinas/aislamiento & purificación , Medios de Cultivo/química , Lactobacillus/crecimiento & desarrollo , Lactobacillus/aislamiento & purificación , ARN Ribosómico 16S/genética , Algoritmos , Animales , Animales Recién Nacidos , Animales Lactantes , Antibacterianos/biosíntesis , Bacteriocinas/biosíntesis , Heces/microbiología , Lactobacillus/genética , Filogenia , Streptococcus suis/efectos de los fármacos , Streptococcus suis/crecimiento & desarrollo , PorcinosRESUMEN
Vibrio harveyi is considered as a causative agent of the systemic disease, vibriosis, which occurs in many biological fields. The effects of temperatures (12.9-27.1 °C) and water activity (NaCl% 0.6%-3.4%) on V. harveyi were investigated. The behavior and growth characteristics of V. harveyi was studied and modeled. Growth curves were fitted by using Gompertz and Baranyi models, and the Baranyi model showed a better fittness. Then, the maximum growth rates (µmax) and lag phase durations (LPD, λ) obtained from both Gompertz and Baranyi model were modeled as a combination function of temperature and water activity using the response surface and Arrhenius-Davey models for secondary model. The value of r(2), MSE, bias and accuracy factor suggest Baranyi model has better fitness than Gompertz model. Furthermore, validation of the developed models with independent data from ComBase also shown better interrelationship between observed and predicted growth parameter when using Baranyi model.
RESUMEN
Plantaricin E/F (PlnEF) is a pair of two-component class IIb bacteriocin produced by lactic acid bacteria. PlnEF commonly displays potent antimicrobial activity against certain Gram-positive organisms. In this study, we investigated the synergistic activity of PlnEF combined with lactic acid against Gram-negative food and aquaculture potential pathogen Aeromonas hydrophila LPL-1, which is naturally resistant to PlnEF. We applied SDS-PAGE, wavelength-scanning, laser confocal microscopy, flow cytometer, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and two-dimensional electrophoresis to investigate their synergistic inhibitory activities. The results showed that L-lactic acid drove the release of LPS from A. hydrophila, making it possible for PlnEF to contact the inner cell membrane of A. hydrophila. Besides, co-treatment of lactic acid and PlnEF caused severe morphological and intracellular changes of A. hydrophila, including blebs on the cell surface, abnormal cell elongation, inner membrane disruption, pore-forming through the outer and inner membrane, coagulation of the cytoplasm, and structural transformation of DNA. Protein profile analysis revealed that combined treatment of lactic acid and PlnEF inhibited the energy metabolism, protein synthesis, protein folding, and DNA replication in A. hydrophila. These findings proved that PlnEF combined with lactic acid was efficient against A. hydrophila and shed light on bacteriocin's potential and a new inhibition mechanism against A. hydrophila. IMPORTANCE: Bacteriocins and their producing strains are increasingly used to substitute artificial preservatives and antibiotics in the food and aquaculture industries. However, the bacteriocins produced by lactic acid bacteria are efficient to mainly Gram-positive bacteria. Our paper had demonstrated the antimicrobial activity of class IIb bacteriocin against potential Gram-negative pathogen, A. hydrophila LPL-1, when combined with lactic acid. The results could refresh our knowledge about the potential of class IIb bacteriocins produced by lactic acid bacteria.
RESUMEN
Spoilage bacteria seriously influence the flavor and quality of fish meat. In this study, we investigated the quality characteristics, bacterial community, and volatile profiles of refrigerated (4°C) sturgeon filets during 10-day storage. On day 10, the refrigerated samples showed the lowest bacterial diversity and the largest difference in microbiota and biochemistry. The dominant genera in the fresh samples were Macrococcus, Acinetobacter, Moraxella, Brucella, and Pseudomonas, while the dominant bacteria changed into Acinetobacter, Carnobacterium, Macrococcus, Pseudomonas, and Psychrobacter at the end of storage. Our results suggest that these dominant taxa contribute to the spoilage of the refrigerated sturgeon filets. Meanwhile, during the storage, total viable counts, total volatile basic nitrogen, thiobarbituric acid-reactive substances, and trichloroacetic acid-soluble peptide significantly increased (P < 0.05), while the sensory score decreased steadily. Additionally, the ATP-related compounds and the K-value showed similarly increasing trends. The shelf-life of the refrigerated sturgeon filets was less than 8 days. The gas chromatography-ion mobility spectrometry results suggest that hexanal, ethyl acetate, ethanol, butanal, 1-propanol, isopentyl alcohol, 2-pentanone, 2-heptanone, ethyl propanoate, and propyl sulfide are potential chemical spoilage markers. The predicted metabolic pathways indicated an abundant carbohydrate metabolism and amino metabolism in the refrigerated sturgeon filets. This study provides insight into the determinants of sturgeon shelf-life and the spoilage process involved in refrigerated fish.
RESUMEN
Although many coatings and films can improve the quality and shelf life of fish fillets during refrigerated storage, a more multifunctional coating material is needed. In this study, an edible alginate/protein-based coating solution was prepared by incorporating antimicrobial agents. The coating properties were characterized and its effects on the quality and shelf life of sturgeon fillets during refrigeration (4 °C) were investigated. Compared with sodium alginate coating (2% sodium alginate + antibacterial agents, H), the composite coatings (2% sodium alginate + antibacterial agents + 1:15 or 1:10 protein solution, HP-15 and HP-10) exhibited a more stable structure and better light, gas, and water barrier properties, and showed better quality-preservation effects on sturgeon fillets. The composite coatings treatments, especially HP-10 composite coating, exhibited significant (p < 0.05) effects in inhibiting microbial growth, maintaining sensory quality, reducing the production of total volatile basic nitrogen (TVB-N), decreasing nucleotide breakdown, and delaying the lipid oxidation and protein degradation in fillets. These findings confirm that the composite coatings can be used as a multifunctional coating material for freshness preservation of sturgeon fillets to improve quality and extend shelf life.
RESUMEN
Low-molecular-weight chondroitin sulfate (CS) has attracted widespread attention due to its better bioavailability and bioactivity than native CS. In this study, a low-molecular-weight CS (named SCS-F2) was prepared from hybrid sturgeon (Acipenser schrenckii × Huso dauricus) cartilage by enzymatic depolymerization with high in vitro absorption and anti-cancer activity. The structure of SCS-F2 was characterized and the in vivo biodistribution and colorectal cancer prevention effect was investigated. The results revealed that SCS-F2 consisted of 48.84% ΔDi-6S [GlcUAß1-3GalNAc(6S)], 32.11% ΔDi-4S [GlcUAß1-3GalNAc(4S)], 16.05% ΔDi-2S,6S [GlcUA(2S)ß1-3GalNAc(6S)] and 3.0% ΔDi-0S [GlcUAß1-3GalNAc]. Animal study showed that the SCS-F2 could be effectively absorbed and delivered to the tumor site and significantly prevented the growth of HT-29 xenograft by inhibiting cell proliferation and inducing apoptosis without showing any negative effect to normal tissues. Therefore, SCS-F2 could be developed as a potential nutraceutical to protect against colorectal cancer.