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The metabolic capacity of probiotic mixed cultures formed by Lactobacillus and Bifidobacterium strains was assessed through the determination of the acidification profile and the production of amino acids and volatile compounds, during the fermentation of ultra-pasteurized skim milk. Two mixed cultures formed by [L. acidophilus + B. bifidum] and [L. acidophilus + B. animalis] stood out in the production of essential amino acids: His, Ile, Leu, Met, Thr, Trp and Val. As well as increased production of volatile compounds such as: acetoin, 2-heptanone, 2-nonanone, acetic acid, acid butanoic and hexanoic acid, in contrast to commercial fermented dairy products. Additionally, these bacterial mixed cultures were characterized by the production of distinctive volatile compounds: 1-heptanol, diisobutylcarninol, hemellitol, 1-dodecanol, acetone, 2-pentanone, 2-undecanone, ethyl acetate, benzaldehyde as well as valeric, acetyl valeric and isopropylpyruvic acids. Finally, the culture formed by [L. acidophilus + B. bifidum] presented a good acidification profile with a lactic acid production of 26.1 ± 0.1 g / L and pH 3.6 at the end of fermentation. This data suggests a great potential of these mixed cultures to improve the nutritional value and organoleptic characteristics of fermented dairy products, when added as starter or adjunct cultures in the fermentation process.

In the present study, α-amylase and α-glucosidase inhibitory effect and antioxidant activity of capsaicin and piperine from the ethanolic extract of Capsicum chinense (EECch) and Piper nigrum (EEPn...

Mansoa hymenaea (DC.) A.H. Gentry is used in traditional medicine to treat pain, arthritis, and rheumatoid disease. It has also been demonstrated that species belonging to the Mansoa genus exert cy...

This study investigated Lippia palmeri Watt (oregano) phytochemical compounds, their antioxidant capacity, and immunological effects on goat peripheral blood leukocytes (PBL), and on the presence of intermediate polar compounds in goat feces fed dietary oregano. The polar and nonpolar fractions of L. palmeri W. were characterized and phytochemical contents and antioxidant capacity were determined. Twelve healthy Anglo-Nubian goats were used for the in vivo trials, which were randomly assigned to control fed with basal diet, or oregano group fed with basal diet + 2.6% (DM basis) dried oregano leaves. Goat peripheral blood leukocytes (PBL) were isolated for the in vitro study, and PBL were stimulated with oregano extracts at 100 and 150 μg/mL after 24 h. For the in vivo trial, dietary oregano (2.6% on DM basis) was evaluated in the goats for 90 days. Relatively high abundance of carvacrol and thymol phytochemical compounds was found in oregano. The highest antioxidant capacity of oregano extracts was detected at 100 and 150 μg/mL. Nitric oxide production, phagocytosis, and superoxide dismutase activities increased (p

Highly branched neo-fructans (agavins) are natural prebiotics found in Agave plants, with a large capacity to mitigate the development of obesity and metabolic syndrome. Here, we investigated the impact of agavins intake on gut microbiota modulation and their metabolites as well as their effect on metabolic endotoxemia and low-grade inflammation in mice fed high-fat diet. Mice were fed with a standard diet (ST) and high-fat diet (HF) alone or plus an agavins supplement (HF+A) for ten weeks. Gut microbiota composition, fecal metabolite profiles, lipopolysaccharides (LPS), pro-inflammatory cytokines, and systemic effects were analyzed. Agavins intake induced substantial changes in gut microbiota composition, enriching Bacteroides, Parabacteroides, Prevotella, Allobaculum, and Akkermansia genus (LDA > 3.0). l-leucine, l-valine, uracil, thymine, and some fatty acids were identified as possible biomarkers for this prebiotic supplement. As novel findings, agavins supplementation significantly decreased LPS and pro-inflammatory (IL-1α, IL-1β, and TNF-α; p < 0.05) cytokines levels in portal vein. In addition, lipid droplets content in the liver and adipocytes size also decreased with agavins consumption. In conclusion, agavins supplementation mitigate metabolic endotoxemia and low-grade inflammation in association with gut microbiota regulation and their metabolic products, thus inducing beneficial responses on metabolic disorders in high-fat diet-fed mice.

The pandemic caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has quickly spread globally, infecting millions and killing hundreds of thousands of people. Herein, to identify potential antiviral agents, 97 natural amide-like compounds known as alkamides and piperamides were tested against SARS-CoV-2 main protease (Mpro) and RNA-dependent RNA polymerase (RdRp), and the human angiotensin-converting enzyme 2 (ACE2) using molecular docking and molecular dynamics simulations. The docking results showed that alkamides and dimeric piperamides from Piper species have a high binding affinity and potential antiviral activity against SARS-CoV-2. The absorption, distribution, metabolism, and excretion (ADME) profile and Lipinski’s rule of five showed that dimeric piperamides have druglikeness potential. The molecular dynamics results showed that pipercyclobutanamide B forms a complex with Mpro at a similar level of stability than N3-I. Our overall results indicate that alkamides and piperamides, and specifically pipercyclobutanamide B, should be further studied as compounds with SARS-CoV-2 antiviral properties.

In this work, we isolated four Cd-tolerant endophytic bacteria from Typha latifolia roots that grow at a Cd-contaminated site. Bacterial isolates GRC065, GRC066, GRC093, and GRC140 were identified as Pseudomonas rhodesiae. These bacterial isolates tolerate cadmium and have abilities for phosphate solubilization, siderophore production, indole acetic acid (IAA) synthesis, and ACC deaminase activity, suggesting that they are plant growth-promoting rhizobacteria. Bacterial inoculation in Arabidopsis thaliana seedlings showed that P. rhodesiae strains increase total fresh weight and number of lateral roots concerning non-inoculated plants. These results indicated that P. rhodesiae strains promote A. thaliana seedlings growth by modifying the root system. On the other hand, in A. thaliana seedlings exposed to 2.5 mg/l of Cd, P. rhodesiae strains increased the number and density of lateral roots concerning non-inoculated plants, indicating that they modify the root architecture of A. thaliana seedlings exposed to cadmium. The results showed that P. rhodesiae strains promote the development of lateral roots in A. thaliana seedlings cultivated in both conditions, with and without cadmium. These results suggest that P. rhodesiae strains could exert a similar role inside the roots of T. latifolia that grow in the Cd-contaminated environment. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s42770-020-00408-9.

An enzymatic method to produce N-acyl homoserine lactones (AHLs) is described. This report represents the first example of the synthesis of bioactive AHLs using immobilized Candida antarctica lipase as the catalyst. The reaction yields, evaluated by GC-EIMS, ranged from 6 to 99%.

In the search of new and safe antibacterial compounds, the quorum sensing system (QS) modulation by natural products has been studied. As a result, many plant-derived compounds have been identified as potent quorum sensing inhibitors. Piper nigrum L. (black pepper) ethanolic extract inhibits the QS in some Gram-negative bacteria but the active components have not been previously identified. Thus, the objective of this work was to identify the P. nigrum peppercorns main components that block the QS, applying bioassay and chromatographic techniques. Piperine and trichostachine were identified as the main components responsible for the quorum quenching (QQ) activity of P. nigrum peppercorns extract. Piperine at 30 mg/L, decreased the violacein production by Chromobacterium violaceum CV026 by 35%, without affecting bacterial growth. Piperine concentration of 40 mg/L decreases violacein production by C. violaceum CV026 by 70% and growth in only 4.34%. Trichostachine at 50 mg/L decreases violacein production by C. violaceum CV026 by 12%, without affecting bacterial growth. P. nigrum extract concentration of 0.5 g/L decreased violacein production in 40 % and no effects on growth were observed. Neither P. nigrum extract, piperine, nor trichostachine did affect QS of Pseudomonas aeruginosa PAO1. Data here described exhibit the potential of piperamides as modulators of QS, not previously reported., Food science; N-Acyl homoserine lactone; Piper nigrum; Piperamide; Quorum quenching; Quorum sensing.

Naphthenic acids (NAs) are complex mixtures of carboxylic acids from petroleum that have industrial applications and that may be released to the environment after oil spills. There is significant research on the chemical composition and toxicity of water-soluble NAs derived from oil sands mining in Alberta, Canada. Yet, little is known about low molecular weight organic compounds (LMWOC) from these sources. Headspace solid-phase microextraction coupled to gas chromatography-electron impact mass spectrometry was used for LMWOC profiling of commercial NA blends, and an acid-extractable organics (AEOs) mixture from a tailings pond. From Sigma 1, Sigma 2, Merichem NAs and the AEO extract, 54, 56, 40 and 4 compounds were identified, respectively. These include aliphatic and cyclic hydrocarbons, carboxylic acids, alkylbenzenes, phenols, naphthalene and alkyl-naphthalene, and decalin compounds. A sample of oil sands process-affected water (OSPW) and aqueous solutions of the NA blends were evaluated for matrix effects on LMWOC profiles. Principal component and clustering analyses revealed that LMWOC profiles of commercial extracts were closely related but distinct from the AEO and OSPW samples. Some of the identified LMWOC are reported to be genotoxic or carcinogenic, and therefore the NA mixtures and AEOs should be considered hazardous materials and further evaluated.

Chenopodium ambrosioides L. has been used for centuries as traditional medicine in many clinical situations. The objectives of this study were first to assess the nutraceutical potential of C. ambrosioides L. extract through analyses of its chemical composition and antioxidant properties, followed by assessing toxicity and antioxidative activities on fish splenocytes. The second one was to perform an in vivo study using dietary C. ambrosioides L. extract (0.0, 0.5, 1.0 and 2.0%; w/w) for 15 and 30 days (2-week and 4-week treatments) to assess associated-intestine health status by short-chain fatty production, antioxidant enzyme activities and anti-inflammatory effects on Pacific red snapper (Lutjanus peru). Non-polar and polar fractions were detected by gas chromatography/mass spectrometry (GC-MS) in C. ambrosioides, of which the most abundant compounds were carvacrol, phytol, squalene, vitamin E and sucrose. The extract of C. ambrosioides L. enhanced a considerable antiradical and reducing power; fish splenocytes responded positively with higher (88%) cell viability than control. The production of nitric oxide and superoxide anion, as well as superoxide dismutase and catalase activities, were also enhanced in splenocytes treated with C. ambrosioides L. The in vivo study results showed that acetate was the major short-chain fatty acid found in fish receiving C. ambrosioides L. after week four. Pro-inflammatory cytokine gene expression in intestine was modulated in fish fed with C. ambrosioides L. at any time of the experimental trial. In addition, the histological findings suggested that its extract did not cause inflammatory damage in intestine. Overall, the results suggest that C. ambrosioides L. is safe for immune cells and promoting intestinal health status of fish through antioxidant and anti-inflammatory effects, making it an interesting additive in functional diets.

Medicinal plants are alternative supplements to increase antioxidant and immune capacity of farmed fish. In this study, the composition (polyphenols and flavonoids) and antioxidant capacity (FRAP and ABTS) of Chenopodium ambrosioides L. was analyzed; and the effects of dietary (0, 0.5, 1.0, and 2.0%) C. ambrosioides L. on antioxidant and immune parameters were evaluated in Pacific red snapper (Lutjanus peru). The results indicated that C. ambrosioides L. has a strong antioxidant capacity, which was related with a high polyphenol content. Fish fed C. ambrosioides L. had higher hemoglobin content after week 4; while, respiratory burst activity significantly increased in fish fed 0.5% C. ambrosioides L. dose at week 2 and 4. Similarly, leukocyte blood populations significantly increased in fish fed 0.5% C. ambrosioides L. In contrast, fish fed 1.0% C. ambrosioides had antimicrobial activity in skin mucus against Vibrio parahaemolyticus and Aeromonas hydrophila. Moreover, skin mucus anti-protease, lysozyme, and peroxidase activities were enhanced in fish fed 0.5 or 1.0% C. ambrosioides. Finally, superoxide dismutase and catalase activities were higher in fish fed 1.0 or 2.0% C. ambrosioides. In conclusion, the results indicate that dietary C. ambrosioides has antioxidative and immunostimulant properties for innovative applications in finfish.

In this study, we report for the first time the efficiency of pentafluorobenzyl bromide (PFBBr) for naphthenic acid (NA) mixtures derivatization, and the comparison in the optimal conditions to the most common NAs derivatization reagents, BF3/MeOH and N-(t-butyldimethylsilyl)-N-methyltrifluoroacetamide (MTBSTFA). Naphthenic acids are carboxylic acid mixtures of petrochemical origin. These compounds are important for the oil industry because of their corrosive properties, which can damage oil distillation infrastructure. Moreover, NAs are commercially used in a wide range of products such as paint and ink driers, wood and fabric preservatives, fuel additives, emulsifiers, and surfactants. Naphthenic acids have also been found in sediments after major oils spills in the United States and South Korea. Furthermore, the toxicity of the oil sands process-affected water (OSPW), product of the oil sands extraction activities in Canada's oil sands, has largely been attributed to NAs. One of the main challenges for the chromatographic analysis of these mixtures is the resolution of the components. The derivatization optimization was achieved using surface response analysis with molar ratio and time as factors for derivatization signal yield. After gas chromatography-electron impact mass spectrometry (GC/EIMS) analysis of a mixture of NA standards, it was found that the signal produced by PFB-derivatives was 2.3 and 1.4 times higher than the signal produced by methylated and MTBS-derivatives, respectively. The pentafluorobenzyl derivatives have a characteristic fragment ion at 181m/z that is diagnostic for the differentiation of carboxylic and non-carboxylic acid components within mixtures. In the analysis of a Sigma and a Merichem derivatized oil extract NA mixtures, it was found that some peaks lack the characteristic fragment ion; therefore they are not carboxylic acids. Open column chromatography was used to obtain a hexane and a methanol fraction of the Sigma and Merichem mixtures. The components in the hexane fraction, presumably hydrocarbons that did not react with PFBBr were ~7% by weight. The effectiveness of PFBBr was confirmed when the two NA oil extracts were spiked with 8 distinct NA standards and identified by GC/EIMS in the methanol fraction. Here, we also report retention indices of the methyl, MTBS and PFB derivatives of these 8 NAs. The use of PFBBr increases sensitivity, chromatographic resolution, and identification accuracy for the analysis of standards and mixtures of NAs compared to MTBSTFA and BF3/MeOH. This methodology will have wide applications in the elucidation of NA mixtures.

Microorganisms of subaerial biofilms, which develop on the surface of stone monuments, have been widely studied due to their impact on Cultural Heritage deterioration. Nevertheless, these extremophile microorganisms are poorly characterised. In this study, a cyanobacterial strain isolated from an archaeological zone in north-central Mexico was characterised through a polyphasic study based on ecological, morphological, and molecular data. Phylogenetic analyses were done using sequences of the 16S rRNA gene and the 16S-23S ITS region. Based on the polyphasic data, a new species corresponding to the genus Nodosilinea is described. This alkaliphilic species has optimum growth at pH of 9. Its fatty acid profile indicates that C18:1, 9E and C16:0 are its most abundant fatty acids. Extracellular polymeric substance production was verified on this strain. Only a few species of the genus Nodosilinea have been documented and described, and this is the first report of their presence in central Mexico. Hence the name Nodosilinea chupicuarensis sp. nov. is proposed.