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Abstract
One of the major and yet unsolved threats for viticulture is the group of vascular fungal infections, the so-called grapevine trunk diseases. Besides their latent nature and the enormous number of associated pathogens, their control is also hampered by the lack of effective fungicides, directing growing attention toward the use of biocontrol agents. In the present study the isolation, identification, and characterization of a bacterial strain are presented, showing biocontrol potential against some main causal agents of grapevine trunk diseases. The strain was isolated from the wood of an asymptomatic grapevine and selected for the fungicidal activity against the pathogen Phaeomoniella chlamydospora. According to 16S rDNA, gyrA, and gyrB sequences, the isolate belongs to Bacillus velezensis species. Confrontation tests with the bacterium or with its fermentation broth further revealed growth inhibition and fungicide activity against Botryosphaeria dothidea, Eutypa lata and Diaporthe ampelina pathogens. Fractionation of the bacterial culture filtrate suggests that the antifungal agents secreted by the B. velezenzis isolate are mainly lipoproteins. Phytotoxicity tests were also carried out with the isolate, showing no harmful effects on grapevine foliar disks.
Abstract
Soluble dietary fibre (SDF) is well recognised for its remarkable effectiveness in promoting human health. This study utilised response surface methodology to evaluate the optimal conditions required to extract SDF (U-SDF) from Lentinula edodes via the ultrasonic-assisted hot-water method, and evaluated the hypolipidemic effects and anti-inflammatory effects of U-SDF. The optimal extraction conditions for U-SDF were ultrasonic power of 182 W, extraction time of 2 h, extraction temperature of 81 °C, and solid-liquid ratio of 1:24 (g mL−1). Under these conditions, the extraction rate of U-SDF reached 8.08%. U-SDF treatment significantly improved liver and kidney indices in diabetic mice, markedly reduced the levels of plasma triglycerides (TG), total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), and significantly increased the level of high-density lipoprotein-cholesterol (HDL-C) in a dose-dependent manner. U-SDF also improved adipose tissue injury in diabetic mice, significantly decreased the levels of cytokines interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumour necrosis factor-α (TNF-α), and alleviated inflammation of the abdominal aorta. In conclusion, U-SDF from L. edodes is an excellent source of dietary fibres, which exhibit good hypolipidemic and anti-inflammatory activities, suggesting potential applications as a functional additive in diverse food products.
Abstract
Food industrial bacterial cells eliminate aflatoxin M1 (AFM1) at different ratios. The study aimed to investigate the effect of AFM1 on probiotic industrial bacteria (Lactococcus lactis ssp. lactis R703, Bifidobacterium animalis ssp. lactis BB12, and L. paracasei subsp. paracasei 431) and evaluating their AFM1 binding ability in naturally contaminated milk. The growth of the R703 strain was affected by AFM1 at 1.47 μg L−1 concentration. Peptidoglycan (PG) cell wall fractions of R703 and BB12 bound a significant amount of AFM1 from naturally contaminated milk under one-hour treatment, while L. paracasei 431 was not effective. PG was better absorbent for AFM1 than viable cells of BB12, while the difference was insignificant for the R703 strain. Increasing the time did not significantly change the mycotoxin binding of BB12, while for R703 PG the absorption seemed reversible. BB12 PG needs further analysis for biotechnological application in dairy products.
Abstract
The aim of this work was to microencapsulate propolis phenolic compounds using polycaprolactone as wall material by double emulsion solvent evaporation (w1/o/w2). Microencapsulation experiments were carried out by investigating the effect of sample/solvent ratio (10–100 mg mL−1), poly(ε-caprolactone) (PCL) concentrations (200–1,000 mg mL−1), poly(vinyl alcohol) (PVA) concentrations (0.5–2.5 g mL−1), and stirring speed (200–1,000 r.p.m.) on the microencapsulation efficiency of total phenolic content (TPC%) and antioxidant activity of propolis. The best microencapsulation conditions were selected according to the total phenolic amount and their antioxidant activity. Experimental results showed that all microencapsulation conditions had significant effects (P < 0.05) on total phenolic content and antioxidant activities. The best conditions were: 30 mg mL−1, 600 mg mL−1, 2 g mL−1, and 400 r.p.m. for sample/solvent ratio, PCL concentrations, PVA concentrations, and stirring speed, respectively, with values of 86.98 ± 0.03% for phenolic encapsulation efficiency, 53.81 ± 0.50% for free radical scavenging activity (DPPH), and 45,480 Trolox equivalent, mg TE/100 g dry weight for ferric reducing antioxidant power (FRAP). Under all encapsulation conditions, a significant positive correlation was observed between ferric reducing antioxidant power, free radical scavenging activity, and phenolic content.
Abstract
The effects of milk from different species (sheep/cow) and pH adjustment in the production of Requeijão cremoso, a kind of processed cheese, were investigated. The results showed that the sheep's Requeijão cremoso had higher pH (∼3%), lower yellowness index (∼11%), and lower brightness (∼12%) after 5 days of storage, and at least 40% lower hardness compared to the Requeijão made from cow milk. The pH adjustment did not change the visual appearance of the samples but affected their hardness in different ways, with an increase of up to 16% for the cheese from cow milk and a reduction of up to 39% for the cheese produced from sheep milk. The results suggested that the protein-protein interactions were favoured in the Requeijão cremoso from sheep milk, while a protein network with higher water holding capacity and increased hardness was observed for the samples from cow milk.
Abstract
This work used a carrageenan-based thrombosis model to determine the preventative effects of Lactobacillus plantarum YS1 (LPYS1) on thrombus. In thrombotic mice, LPYS1 improved the activated partial thromboplastin time (APTT), while decreasing the thrombin time (TT), prothrombin time (PT), and fibrinogen (FIB) content. In thrombotic mouse serum, LPYS1 decreased the levels of malondialdehyde (MDA), tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), nuclear factor kappa-B (NF-κB), and interleukin-1 beta (IL-1β), while also increasing the activities of superoxide dismutase (SOD) and catalase (CAT). Moreover, LPYS1 upregulated the mRNA expression levels of copper/zinc-SOD (Cu/Zn-SOD), manganese-SOD (Mn-SOD), and CAT in the colon tissues of thrombotic mice, while downregulating those of NF-κB p65, IL-6, TNF-α, and interferon-gamma (IFN-γ) mRNA. In tail vein vascular tissues, LPYS1 suppressed the mRNA expression levels of NF-κB p65, intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin. The abundances of both beneficial and pathogenic bacteria were altered by LPYS1. These findings show that LPYS1 has the capacity to protect mice from thrombosis, while also revealing some of the underlying mechanisms of this effect.
Abstract
The activity and structural variation of glycogen phosphorylase (GP) at different phosphorylation levels during incubation at 4 °C were explored in this study. The GP was assigned into four treatments to obtain high/low phosphorylation levels, which were (1) treated with glycogen phosphorylase kinase (Phk) to obtain high phosphorylation level, (2) treated with protein kinase A to obtain high phosphorylation level, (3) treated with alkaline phosphatase to obtain low phosphorylation level, and (4) control. Compared with the control group, the content of α-helix and β-sheet increased and the secondary structure of GP changed from disorder to order after phosphorylation. The activity of GP was increased and its structure was more tightly in the Phk group than that in the control group. The phosphorylation at Ser277, Ser430, Ser809, Thr304, Tyr298, and Tyr525 resulted in tighter spatial structure. In conclusion, phosphorylation of GP enhanced its catalytic activity by making the secondary and spatial structure more orderly, which is of great significance for controlling meat quality by regulating glycolysis.
Abstract
Carob pulp is a natural source of polyphenols, which have been shown to possess health benefits. These compounds play a crucial role in initiating, shaping, and modulating the gut microbiota. The objective of this study was to evaluate the impact of carob pulp phenolic extracts on nine specific groups of human gut microbiota before and after in vitro gastrointestinal digestion. The effects of pure gallic and coumaric acids were also tested. The results showed that the treated phenolic compounds exhibited inhibitory effects on the growth of most pathogenic bacteria. Gallic acid, in particular, demonstrated the most potent antimicrobial effect on Listeria monocytogenes, reducing its growth to below 5%. Staphylococcus aureus and Escherichia coli showed a growth reduction of up to 10%. Furthermore, both phenolic acids, before and after digestion, led to a slight reduction in E. coli O157:H7 numbers. Probiotic bacteria experienced minimal decrease following exposure to phenolic extracts. However, the growth of Lactobacillus casei ssp. rhamnosus was significantly inhibited by almost 50%. Interestingly, the in vitro digestion process exhibited a stronger antibacterial effect against pathogenic bacteria compared to probiotic bacteria. These results highlight the potential of carob phenolic extracts in modulating the intestinal microbiota, thereby offering interesting prospects for the development of diet-based health strategies.
Abstract
The bacterial spirochete Borrelia burgdorferi, the causative agent of Lyme Disease, can disseminate and colonize various tissues and organs, orchestrating severe clinical symptoms including arthritis, carditis, and neuroborreliosis. Previous research has demonstrated that breast cancer tissues could provide an ideal habitat for diverse populations of bacteria, including B. burgdorferi, which is associated with a poor prognosis. Recently, we demonstrated that infection with B. burgdorferi enhances the invasion and migration of triple-negative MDA-MB-231 cells which represent a type of breast tumor with more aggressive cancer traits. In this study, we hypothesized that infection by B. burgdorferi affects the expression of cancer-associated genes to effectuate breast cancer phenotypes. We applied the high-throughput technique of RNA-sequencing on B. burgdorferi-infected MDA-MB-231 breast cancer and normal-like MCF10A cells to determine the most differentially expressed genes (DEG) upon infection. Overall, 142 DEGs were identified between uninfected and infected samples in MDA-MB-231 while 95 DEGs were found in MCF10A cells. A major trend of the upregulation of C-X-C and C-C motif chemokine family members as well as genes and pathways was associated with infection, inflammation, and cancer. These genes could serve as potential biomarkers for pathogen-related tumorigenesis and cancer progression which could lead to new therapeutic opportunities.
Abstract
Infections caused by Staphylococcus aureus are currently a worldwide threat affecting millions of individuals. The pathogenicity of S. aureus is associated with numerous virulence factors, including cell surface proteins, polysaccharides, and secreted toxins. The pore-forming α-hemolysin, known as α-toxin, is produced by nearly all virulent strains of S. aureus and is implicated in several diseases including skin and soft tissue infections, atopic dermatitis, and pneumonia. There are currently no vaccines available for the prevention of S. aureus infections and the efficacy of available antibiotics has been fading. In this study we examined the mode of antihemolytic activity of theaflavin-3,3′-digallate against α-hemolysin of methicillin-resistant S. aureus by molecular docking using AutoDock Vina as the molecular docking tool. The theaflavin-3,3′-digallate docked the molecular sequence of the Hla (PDB ID:7ahl). The scores of the top 10 binding modes obtained were between −9.0 and −8.5 kcal mol−1, and the best binding mode was −9.0 kcal mol−1. Direct binding sites of theaflavin-3,3′-digallate to the “stem” domain of Hla were revealed which primarily targeted of the residues Met113, Thr117, Asn139. The disclosure of this potential binding mode warrants further clinical evaluation of theaflavin-3,3′-digallate as an anti-hemolytic compound in order to practically validate our results.
