Phenolic Composition and Antimicrobial Activity of Different Emirati Date (Phoenix dactylifera L.) Pits: A Comparative Study.
The biochemical composition, secondary metabolites (phenolic compounds, flavonoids) and antimicrobial potential of different varieties of Emirati date (Phoenix dactylifera L.) pits were investigated. Total phenolic acids (TPC) and total flavonoid contents (TFC) of the different date pits were measured using a Folin-Ciocalteau reagent. Different organic solvents [(n-hexane; H2O: EtOH (1:1); ethyl acetate; acetone: Water (1:1); and methanol: Chloroform (1:1)] were compared to evaluate the phytotoxicity of Ajwa, Fard, Khalas, Khodari, Abu Maan, Lulu, and Mabroom date pits. The antimicrobial activity of the date pit extracts were evaluated by means of agar-well diffusion assay on Staphylococcus aureus (ATCC 29123), Escherichia coli (ATCC 25922) and Candida albicans (ATCC 66027). Minimum inhibitory concentrations (MICs) were measured following clinical laboratory standardization institute (CLSI) protocol. The biochemical analyses of date pits indicate that TPC were ranged from 7.80 mg of equivalent gallic acid/100 g dry weight in Ajwa to 4.65 mg in Mabroom. The TFC were ranged between 1.6-4.54 mg of equivalent catechin/100 g dry weight. Ajwa pit extract showed good quality traits (higher protein, lower ash content, and intermediate dietary fiber). The results indicate that the ethyl acetate extract of Khalas and Khodari inhibited S. aureus with an inhibition zone diameter of 20 mm and MIC of 10 mg/mL. Abu Mann pit extract inhibited the S. aureus and also decreased the population of E. coli. The diameter of inhibition zone was 15, 16, and 18 mm after treatment with Ajwa extracts, while the MICs were 7.5 and 5 mg/mL. The MeOH: CFM extract of Abu Mann and Ajwa was more potent against E. coli bacteria than any other extract. This work demonstrates that the Emirati date pits extract has antimicrobial (antibacterial, antifungal) potential and can be used as phytotoxic natural compounds.
Twelve complete chloroplast genomes of wild peanuts: great genetic resources and a better understanding of Arachis phylogeny.
BACKGROUND: The cultivated peanut (Arachis hypogaea) is one of the most important oilseed crops worldwide, however, its improvement is restricted by its narrow genetic base. The highly variable wild peanut species, especially within Sect. Arachis, may serve as a rich genetic source of favorable alleles to peanut improvement; Sect. Arachis is the biggest taxonomic section within genus Arachis and its members also include the cultivated peanut. In order to make good use of these wild resources, the genetic bases and the relationships of the Arachis species need first to be better understood. RESULTS: Here, in this study, we have sequenced and/or assembled twelve Arachis complete chloroplast (cp) genomes (eleven from Sect. Arachis). These cp genome sequences enriched the published Arachis cp genome data. From the twelve acquired cp genomes, substantial genetic variation (1368 SNDs, 311 indels) has been identified, which, together with 69 SSR loci that have been identified from the same data set, will provide powerful tools for future explorations. Phylogenetic analyses in our study have grouped the Sect. Arachis species into two major lineages (I & II), this result together with reports from many earlier studies show that lineage II is dominated by AA genome species that are mostly perennial, while lineage I includes species that have more diverse genome types and are mostly annual/biennial. Moreover, the cultivated peanuts and A. monticola that are the only tetraploid (AABB) species within Arachis are nested within the AA genome species-dominated lineage, this result together with the maternal inheritance of chloroplast indicate a maternal origin of the two tetraploid species from an AA genome species. CONCLUSION: In summary, we have acquired sequences of twelve complete Arachis cp genomes, which have not only helped us better understand how the cultivated peanut and its close wild relatives are related, but also provided us with rich genetic resources that may hold great potentials for future peanut breeding.
Kinetic and equilibrium study of the removal of reactive dye using modified walnut shell.
Modified walnut shell (EAWNS) was prepared by reaction with epichlorohydrin and alkaline solution of aspartic acid and used to remove reactive dye (Reactive Brilliant Blue (KN-R)) from aqueous media. The isotherms, kinetics and thermodynamics of KN-R adsorption onto EAWNS were studied at 298-318 K. The isotherm data of KN-R adsorption onto EAWNS agreed closely with the Langmuir model. The theoretical monolayer adsorption capacity for KN-R was 224.42 mg/g at 318 K. The result from the Dubinin-Radushkevich model showed that the KN-R adsorption onto EAWNS is chemisorption. The adsorption rate of KN-R onto EAWNS conformed to the pseudo-second-order model. The diffusion mechanism was investigated by the intraparticle diffusion model. The mass-transfer coefficient calculated by the surface mass-transfer coefficient model was in range of 2.95 × 10-5 to 2.93 × 10-4cm/s. The thermodynamic results suggested that the adsorption of KN-R onto EAWNS is spontaneous and endothermic in nature. The design of a single-stage batch adsorption process based on EAWNS adsorbent was carried out. Furthermore, the recycled EAWNS maintains high adsorption capacity despite four cycles.
Intraspecific variability of growth and ochratoxin A production by Aspergillus carbonarius from different foods and geographical areas.
Ochratoxin A (OTA) is a nephrotoxic mycotoxin naturally found in a wide range of food commodities throughout the world. Aspergillus carbonarius is the most important source of OTA in food commodities such as wine, grapes and dried vine fruits and is also responsible for the formation of OTA in coffee. The aim of this study was to determine the simultaneous effect of three culture media (Czapek Yeast Extract Broth (CYB); Synthetic Grape Juice Medium (SGM) and White grape juice (WGJ)) at three water activity (aw) levels (0.90; 0.95 and 0.98-0.99), and three incubation temperatures (15 °C, 25 °C and 35 °C) on the growth and OTA production by 16 strains of A. carbonarius. The strains were mainly isolated from grapes from areas with a Mediterranean climate. All the strains were confirmed for identity by sequencing of the calmodulin gene. The assay was performed in microtiter plates, determining the absorbance at 530 nm and the concentration of OTA after 1, 2, 4 and 10 days of incubation. No significant differences were observed in absorbance values between the strains. The highest absorbance values were recorded in CYB at 0.99 aw and at 0.95 aw after 10 days of incubation at 25 °C and 35 °C. None of the strains were able to grow at 0.90 aw and 15 °C in any culture media after 10 days of incubation. OTA concentration was statistically higher at 15 °C than at 25 °C or 35 °C. The highest significant OTA values were obtained at 0.98-0.99 aw and the best culture media for OTA production was CYB, followed by WGJ and SGM. While strains isolated from Mediterranean climate foods had a similar behavior despite being isolated from different geographical areas, OTA concentration produced by one Robusta coffee strain from Thailand was statistically higher at 25 °C than at 15 °C. This would suggest that the type of food matrices and consequently the adaptation of A. carbonarius strains to different climatic conditions would have a greater influence on the ecophysiology of the strains than only their geographical origin.
Genome-wide identification of microsatellite markers from cultivated peanut (Arachis hypogaea L.).
BACKGROUND: Microsatellites, or simple sequence repeats (SSRs), represent important DNA variations that are widely distributed across the entire plant genome and can be used to develop SSR markers, which can then be used to conduct genetic analyses and molecular breeding. Cultivated peanut (A. hypogaea L.), an important oil crop worldwide, is an allotetraploid (AABB, 2n = 4× = 40) plant species. Because of its complex genome, genomic marker development has been very challenging. However, sequencing of cultivated peanut genome allowed us to develop genomic markers and construct a high-density physical map. RESULTS: A total of 8,329,496 SSRs were identified, including 3,772,653, 4,414,961, and 141,882 SSRs that were distributed in subgenome A, B, and nine scaffolds, respectively. Based on the flanking sequences of the identified SSRs, a total of 973,984 newly developed SSR markers were developed in subgenome A (462,267), B (489,394), and nine scaffolds (22,323), with an average density of 392.45 markers per Mb. In silico PCR evaluation showed that an average of 88.32% of the SSR markers generated only one in silico-specific product in two tetraploid A. hypogaea varieties, Tifrunner and Shitouqi. A total of 39,599 common SSR markers were identified among the two A. hypogaea varieties and two progenitors, A. duranensis and A. ipaensis. Additionally, an amplification effectiveness of 44.15% was observed by real PCR validation. Moreover, a total of 1276 public SSR loci were integrated with the newly developed SSR markers. Finally, a previously known leaf spot quantitative trait locus (QTL), qLLS_T13_A05_7, was determined to be in a 1.448-Mb region on chromosome A05. In this region, a total of 819 newly developed SSR markers were located and 108 candidate genes were detected. CONCLUSIONS: The availability of these newly developed and public SSR markers both provide a large number of molecular markers that could potentially be used to enhance the process of trait genetic analyses and improve molecular breeding strategies for cultivated peanut.
Persistence of a mixed lactic acid bacterial starter culture during lysine fortification of sourdough breads by addition of pistachio powder.
Pistachio powder was added to flour or semolina to evaluate its contribution to increase the amount of lysine in bread. Bread production was carried out by sourdough technology using a selected 3-species (Lactobacillus sanfranciscensis/Leuconostoc citreum/Weissella cibaria) lactic acid bacterial (LAB) starter culture. All sourdoughs were subjected to a long-time fermentation (21 h) and showed levels of LAB around 109 CFU/g, indicating the suitability of pistachio powder for lactic fermentation. Yeasts were also detected, in particular in semolina trials. MiSeq Illumina technology was applied to investigate the bacterial composition of sourdoughs evidencing a different distribution of LAB species among the trials with Lactobacillus as major LAB group in almost all sourdoughs. Physicochemical parameters were comparable among the trials. After baking, pistachio powder was found not to influence the height of the breads, but pistachio breads were more firm than control breads. Color of the breads, void fraction and cell density, were influenced by pistachio powder. The amount of lysine increased consistently thanks to pistachio supplementation which also determined a higher presence of o-xylene, p-cymene and limonene and the appearance of α-pinene and 1-octen-3-ol in breads. Sensory tests showed the best appreciation scores for the breads produced with flour and pistachio powder.
Oral immunotherapy for hazelnut allergy: a single-center retrospective study on 100 patients.
BACKGROUND: Oral immunotherapy (OIT) protects patients with IgE-mediated food allergies from food-induced allergic reactions due to accidental exposure and may improve their quality of life. This approach has never been evaluated for hazelnut, a major cause of food allergy in Europe. OBJECTIVE: We sought to determine the proportion of hazelnut-desensitized patients after 6 months of OIT and to identify predictors of successful desensitization. METHOD: In a retrospective single-center study, we included patients under 18 years of age who underwent at least 6 months of hazelnut OIT for IgE-mediated allergy, defined by history of hypersensitivity reaction after hazelnut ingestion, positive hazelnut skin prick test (SPT) or specific IgE, and positive double-blind, placebo-controlled food challenge (DBPCFC). Patients able to tolerate 1635 mg of hazelnut protein (approximately 8 hazelnuts) were considered to be hazelnut desensitized. We determined the proportion of desensitized patients after 6 months of OIT, searched for associations between baseline variables and successful desensitization, and estimated the frequency and severity of OIT-related adverse reactions. RESULTS: One hundred patients were included (64% male, median age 5 years). History of severe reactions was noted in 7% of cases. At 6 months, the proportion of desensitized patients was 34% (95%CI: 25-44). The median eliciting dose (defined as the amount of hazelnut protein provoking a hypersensitivity reaction during the DBPCFC) increased from 106 mg [IQR: 51-249] at baseline to 523 mg [IQR: 190-1635] after 6 months of OIT (p<0.0001). With longer therapy, the proportion of desensitized patients increased. Using multivariate analysis, successful desensitization was associated with older age (OR: 1.5, 95%CI: 1.2-2.2), smaller hazelnut SPT wheal diameter (OR: 0.61, 95%CI: 0.4-0.8), lower hazelnut specific IgE level (OR: 0.86, 95%CI: 0.72-0.98), and absence of cashew allergy (OR: 0.42, 95%CI: 0.12-0.64). Adverse reactions occurred in 30% of patients; none were severe. CONCLUSION: In a cohort of 100 patients aged 3-9 years, our results show for the first time that hazelnut OIT is associated with hazelnut desensitization and may be safe in the majority of patients undergoing this therapy.
Molecular evolution of genes encoding allergen proteins in the peanuts genus Arachis: Structural and functional implications.
Food allergies are severe immune responses to plant and animal products mediated by immunoglobulin E (IgE). Peanuts (Arachis hypogaea L.) are among the top 15 crops that feed the world. However, peanuts is among the "big eight food allergens", and allergies induced by peanuts are a significant public health problem and a life-threatening concern. Targeted mutation studies in peanuts demonstrate that single residue alterations in these allergen proteins could result in substantial reduction in allergenicity. Knowledge of peanut allergen proteins is confined to the allotetraploid crop and its two progenitors. We explored frequencies and positions of natural mutations in the hyperallergenic homologues Ara h 2 and Ara h 6 in newly generated sequences for 24 Arachis wild species and the crop species, assessed potential mutational impact on allergenicity using immunoblots and structural modeling, and evaluated whether these mutations follow evolutionary trends. We uncovered a wealth of natural mutations, both substitutions and gaps, including the elimination of immunodominant epitopes in some species. These molecular alterations appear to be associated with substantial reductions in allergenicity. The study demonstrated that Ara h 2 and Ara h 6 follow contrasting modes of natural selection and opposing mutational patterns, particularly in epitope regions. Phylogenetic analysis revealed a progressive trend towards immunodominant epitope evolution in Ara h 2. The findings provide valuable insight into the interactions among mutations, protein structure and immune system response, thus presenting a valuable platform for future manipulation of allergens to minimize, treat or eliminate allergenicity. The study strongly encourages exploration of genepools of economically important plants in allergenicity research.
Component-resolved diagnostics can be useful for identifying hazelnut allergy in Japanese children.
BACKGROUND: Microsatellites, or simple sequence repeats (SSRs), represent important DNA variations that are widely distributed across the entire plant genome and can be used to develop SSR markers, which can then be used to conduct genetic analyses and molecular breeding. Cultivated peanut (A. hypogaea L.), an important oil crop worldwide, is an allotetraploid (AABB, 2n = 4× = 40) plant species. Because of its complex genome, genomic marker development has been very challenging. However, sequencing of cultivated peanut genome allowed us to develop genomic markers and construct a high-density physical map. RESULTS: A total of 8,329,496 SSRs were identified, including 3,772,653, 4,414,961, and 141,882 SSRs that were distributed in subgenome A, B, and nine scaffolds, respectively. Based on the flanking sequences of the identified SSRs, a total of 973,984 newly developed SSR markers were developed in subgenome A (462,267), B (489,394), and nine scaffolds (22,323), with an average density of 392.45 markers per Mb. In silico PCR evaluation showed that an average of 88.32% of the SSR markers generated only one in silico-specific product in two tetraploid A. hypogaea varieties, Tifrunner and Shitouqi. A total of 39,599 common SSR markers were identified among the two A. hypogaea varieties and two progenitors, A. duranensis and A. ipaensis. Additionally, an amplification effectiveness of 44.15% was observed by real PCR validation. Moreover, a total of 1276 public SSR loci were integrated with the newly developed SSR markers. Finally, a previously known leaf spot quantitative trait locus (QTL), qLLS_T13_A05_7, was determined to be in a 1.448-Mb region on chromosome A05. In this region, a total of 819 newly developed SSR markers were located and 108 candidate genes were detected. CONCLUSIONS: The availability of these newly developed and public SSR markers both provide a large number of molecular markers that could potentially be used to enhance the process of trait genetic analyses and improve molecular breeding strategies for cultivated peanut.
NMR resonance assignments of the four isoforms of the hazelnut allergen Cor a 1.04.
In large parts of Europe, Northern America and China people are suffering from allergies after consuming certain kinds of fruits and vegetables. Typical allergic symptoms range from scratching and itching of the throat to severe symptoms like rhino conjunctivitis and anaphylaxis. For hazelnuts (Corylus avellana), these allergies result from initial sensitization to the birch (Betula verrucosa) pollen allergen Bet v 1 and subsequent development of allergic cross-reactions to proteins that are similar in their three-dimensional structure to the sensitizing protein Bet v 1. The cross-reactive proteins in hazelnut are the four isoforms Cor a 1.04 with a molecular weight of about 17.5 kDa. Significant differences regarding the immunologic behavior of these proteins have been reported. In this work we assigned backbone and side chain 1H, 13C, and 15N chemical shifts of these four isoforms, Cor a 1.0401, Cor a 1.0402, Cor a 1.0403, and Cor a 1.0404 by solution NMR spectroscopy. The chemical shift data confirm the characteristic Bet v onefold for all four isoforms, consisting of seven β-strands that are separated by two short α-helices, along with a long C-terminal α-helix. These data provide the basis for a comparative structural and dynamic analysis of these proteins by NMR in order to characterize their different immunologic cross-reactivities on a molecular level.