Estamaran date vinegar: chemical and microbial dynamics during fermentation.

Vinegar is a fermented food produced by alcoholic and then acetic acid microbial metabolism. Date palm fruit (Phoenix dactylifera L.) is a valuable source for the production of vinegar. Microbial identification has a major role in the improvement and bio-management of the fermentation process of vinegar. Estamaran and Kabkab two varieties of date palm fruit were selected to study the fermentation process. A culture-dependent approach was used to study bacterial dynamics. 16 S rRNA gene was amplified by Polymerase Chain Reaction (PCR), also restriction enzyme analysis with HinfI and TaqI, and sequencing was done. Assessment of microbial flora of date palm fruit during fermentation showed that Fructobacillus tropaeoli, Bacillus sp., Leuconostoc mesenteroides, Leuconostoc pseudomesenteroides, and Weissella paramesenteroides existed in the first phase of fermentation. With fermentation progress, microbial diversity decreased so only one species remained. Komagataeibacter xylinus as an acid acetic producer was present in the third phase of fermentation. Based on chemical analysis, the concentration of reducing sugars decreased during fermentation. With decreasing pH, a simultaneous increase in acidity and total phenolic compounds occurred. The trend of changes during Estamaran fermentation was more severe and a vinegar with desirable properties was produced. Therefore, this date variety is recommended for the production of date vinegar.

Endophytic fungi are able to induce tolerance to salt stress in date palm seedlings (Phoenix dactylifera L.).

Date palm, typically considered a salinity-resistant plant, grows in arid and semi-arid regions worldwide, and experiences decreased growth and yields under salt stress. This study investigates the efficacy of endophytic fungi (EF) in enhancing the salinity tolerance of date palm seedlings. In this experiment, EF were isolated from date tree roots and identified morphologically. Following molecular identification, superior strains were selected to inoculate date palm seedlings (Phoenix dactylifera L., cv. Mazafati). The seedlings were subjected to varying levels of salinity stress for 4 months, utilizing a completely randomized factorial design with two factors: fungal strain type (six levels) and salinity stress (0, 100, 200, and 300 mM sodium chloride). The diversity analysis of endophytic fungi in date palm trees revealed that the majority of isolates belonged to the Ascomycota family, with Fusarium and Alternaria being the most frequently isolated genera. In this research, the application of fungal endophytes resulted in increased dry weight of roots, shoots, root length, plant height, and leaf number. Additionally, EF symbiosis with date palm seedling roots led to a reduction in sodium concentration and an increase in potassium and phosphorus concentrations in aerial parts under salt-stress conditions. While salinity elevated lipid peroxidation, consequently increasing malondialdehyde (MDA) levels, EF mitigated damage from reactive oxygen species (ROS) by enhancing antioxidant enzyme activity, including superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX), while promoting proline and total soluble sugar (TSS) accumulation. The colonization percentage generally increased with salinity stress intensity in most strains. According to the results, the application of EF can alleviate the adverse effects of salinity stress and enhance the growth of date palm seedlings under saline conditions.

Salinity of irrigation water selects distinct bacterial communities associated with date palm (Phoenix dactylifera L.) root.

Saline water irrigation has been used in date palm (Phoenix dactylifera L.) agriculture as an alternative to non-saline water due to water scarcity in hyper-arid environments. However, the knowledge pertaining to saline water irrigation impact on the root-associated bacterial communities of arid agroecosystems is scarce. In this study, we investigated the effect of irrigation sources (non-saline freshwater vs saline groundwater) on date palm root-associated bacterial communities using 16S rDNA metabarcoding. The bacterial richness, Shannon diversity and evenness didn't differ significantly between the irrigation sources. Soil electrical conductivity (EC) and irrigation water pH were negatively related to Shannon diversity and evenness respectively, while soil organic matter displayed a positive correlation with Shannon diversity. 40.5% of total Operational Taxonomic Units were unique to non-saline freshwater irrigation, while 26% were unique to saline groundwater irrigation. The multivariate analyses displayed strong structuring of bacterial communities according to irrigation sources, and both soil EC and irrigation water pH were the major factors affecting bacterial communities. The genera Bacillus, Micromonospora and Mycobacterium were dominated while saline water irrigation whereas contrasting pattern was observed for Rhizobium, Streptomyces and Acidibacter. Taken together, we suggest that date-palm roots select specific bacterial taxa under saline groundwater irrigation, which possibly help in alleviating salinity stress and promote growth of the host plant.

Induction of Defense Gene Expression and the Resistance of Date Palm to Fusarium oxysporum f. sp. Albedinis in Response to Alginate Extracted from Bifurcaria bifurcata.

In many African countries, the Bayoud is a common disease spread involving the fungus Fusarium oxusporum f. sp. albedinis (Foa). The induction of plant natural defenses through the use of seaweed polysaccharides to help plants against pathogens is currently a biological and ecological approach that is gaining more and more importance. In the present study, we used alginate, a natural polysaccharide extracted from a brown algae Bifurcaria bifurcata, to activate date palm defenses, which involve phenylalanine ammonia-lyase (PAL), a key enzyme of phenylpropanoid metabolism. The results obtained showed that at low concentration (1 g·L-1), alginate stimulated PAL activity in date palm roots 5 times more compared to the negative control (water-treated) after 24 h following treatment and 2.5 times more compared to the laminarin used as a positive stimulator of plant natural defenses (positive control of induction). Using qRT-PCR, the expression of a selection of genes involved in three different levels of defense mechanisms known to be involved in response to biotic stresses were investigated. The results showed that, generally, the PAL gene tested and the genes encoding enzymes involved in early oxidative events (SOD and LOX) were overexpressed in the alginate-treated plants compared to their levels in the positive and negative controls. POD and PR protein genes selected encoding ß-(1,3)-glucanases and chitinases in this study did not show any significant difference between treatments; suggesting that other genes encoding POD and PR proteins that were not selected may be involved. After 17 weeks following the inoculation of the plants with the pathogen Foa, treatment with alginate reduced the mortality rate by up to 80% compared to the rate in control plants (non-elicited) and plants pretreated with laminarin, which agrees with the induction of defense gene expression and the stimulation of natural defenses in date palm with alginate after 24 h. These results open promising prospects for the use of alginate in agriculture as an inducer that triggers immunity of plants against telluric pathogens in general and of date palm against Fusarium oxysporum f. sp. albedinis in particular.

Phylogeny and Mycotoxin Profile of Pathogenic Fusarium Species Isolated from Sudden Decline Syndrome and Leaf Wilt Symptoms on Date Palms (Phoenix dactylifera) in Tunisia.

In 2017-2018, extensive symptoms of sudden decline and fruit rot were observed on date palms in southern Tunisia. Samples of diseased plants were randomly collected in six localities. Based on morphological identification, Fusarium was the most frequent fungal genus detected. A sequencing of translation elongation factor, calmodulin, and second largest subunit of RNA polymerase II genes was used to identify 63 representative Fusarium strains at species level and investigate their phylogenetic relationships. The main species detected was Fusariumproliferatum, and at a much lesser extent, Fusariumbrachygibbosum, Fusariumcaatingaense, Fusariumclavum, Fusariumincarnatum, and Fusariumsolani. Pathogenicity on the DegletNour variety plantlets and the capability to produce mycotoxins were also assessed. All Fusarium species were pathogenic complying Koch's postulates. Fusariumproliferatum strains produced mainly fumonisins (FBs), beauvericin (BEA), and, to a lesser extent, enniatins (ENNs) and moniliformin (MON). All F.brachygibbosum strains produced low levels of BEA, diacetoxyscirpenol, and neosolaniol; two strains produced also T-2 toxin, and a single strain produced HT-2 toxin. Fusariumcaatingaense, F.clavum, F.incarnatum produced only BEA. Fusariumsolani strains produced MON, BEA, and ENNs. This work reports for the first time a comprehensive multidisciplinary study of Fusarium species on date palms, concerning both phytopathological and food safety issues.

Molecular and physiological characterization of Fusarium strains associated with different diseases in date palm.

Several species of Fusarium cause serious diseases in date palm worldwide. In the present work, 14 SSR markers were used to assess the genetic variation of Fusarium strains isolated from diseased trees in Saudi Arabia. We also studied the effect of different temperatures on mycelial growth of these strains. The pathogenicity of four strains of F. proliferatum was also evaluated on local date palm cultivars. Eleven SSR markers amplified a total of 57 scorable alleles from Fusarium strains. Phylogenetic analysis showed that F. proliferatum strains grouped in one clade with 95% bootstrap value. Within F. proliferatum clade, 14 SSR genotypes were identified, 9 of them were singleton. Four out of the five multi-individual SSR genotypes contained strains isolated from more than one location. Most F. solani strains grouped in one clade with 95% bootstrap value. Overall, the SSR markers previously developed for F. verticillioides and F. oxysporum were very useful in assessing the genetic diversity and confirming the identity of Saudi Fusarium strains. The results from the temperature study showed significant differences in mycelial growth of Fusarium strains at different temperatures tested. The highest average radial growth for Fusarium strains was observed at 25°C, irrespective of species. The four F. proliferatum strains showed significant differences in their pathogenicity on date palm cultivars. It is anticipated that the assessment of genetic diversity, effect of temperature on hyphal growth and pathogenicity of potent pathogenic Fusarium strains recovered from date palm-growing locations in Saudi Arabia can help in effectively controlling these pathogens.

Crystallicutis gen. nov. (Irpicaceae, Basidiomycota), including C. damiettensis sp. nov., found on Phoenix dactylifera (date palm) trunks in the Nile Delta of Egypt.

The taxonomy of Polyporales is complicated by the variability in key morphological characters across families and genera, now being gradually resolved through molecular phylogenetic analyses. Here a new resupinate species, Crystallicutis damiettensis sp. nov. found on the decayed trunks of date palm (Phoenix dactylifera) trees in the fruit orchards of the Nile Delta region of Egypt is reported. Multigene phylogenetic analyses based on ITS, LSU, EF1α, RPB1 and RPB2 loci place this species in Irpicaceae, and forming a distinct clade with Ceraceomyces serpens and several other hitherto unnamed taxa, which we also incorporate into a new genus Crystallicutis. We name two of these species, Crystallicutis huangshanensis sp. nov. and Crystallicutis rajchenbergii sp. nov. The distinctive feature of Crystallicutis gen. nov. is the presence of crystal-encrusted hyphae in the hymenium and subiculum. Basidiomes are usually honey-yellow with white margins but there is variability in the presence of clamp connections and cystidia, as noted for other genera within Irpicacae. C. damiettensis is hitherto consistently associated with date palms killed by the red palm weevil Rhynchophorus ferrugineus, a highly damaging and invasive pest, recently spread to the Mediterranean region. C. damiettensis causes rapid wood decay by a potentially unusual white-rot mechanism and may play a role in the damage caused by R. ferrugineus.

A preliminary study on mycobiota and ochratoxin a contamination in commercial palm dates (Phoenix dactylifera).

The occurrence of mycotoxins and mycotoxigenic fungi in palm dates has not been thoroughly documented. The aims of the present study were to identify the mycobiota present in commercial date samples (n = 19), to determine the ability of the isolated fungi to produce mycotoxins, and to determine and quantify the presence of OTA in date fruits. The majority of products originated from Tunisia (n = 14) and Algeria (n = 3). The dominant fungal species were Aspergillus niger, Aspergillus tubingensis and Aspergillus flavus which were most frequently found in premium quality and organic produce, produced without chemical preservatives. OTA was found in only one sample at a concentration of 0.75 µg/kg, as determined by HPLC with fluorescence detection. Although this preliminary study did not find elevated levels of OTA, its presence in one out of 19 samples indicates that palm dates for human consumption require continuous and stringent control, in order to prevent contaminated produce from entering the market.

Changes in microbial communities and their predictive functionalities during fermentation of toddy, an alcoholic beverage of India.

Toddy is a traditional mild-alcoholic drink of India, which is produced from fresh palm saps by natural fermentation. We studied the successional changes in bacterial and fungal communities during the natural fermentation (0 h-96 h) of toddy. During fermentation, alcohol content of the fermenting saps increased significantly from 0.6 %±0.15 to 5.6 %±0.02, pH decreased from 6.33 %±0.02-3.93 ± 0.01, volatile and titratable acidity acidity (g/100 mL) increased from 0.17 ± 0.02 (0 h) to 0.48 ± 0.02 (96 h) and 1.30 ± 0.005 (0 h) to 2.47 ± 0.005 (96 h), respectively. Total sugar content and ˚BRIX also decreased during the fermentation. Firmicutes (78.25 %) was the most abundant phylum followed by Proteobacteria (21.57 %). Leuconostoc was the most abundant genus in the early stages of fermentation. However, Lactobacillus and Gluconoacetobacter were found abundant with increase in pH during the later phases of fermentation (72 h-96 h). Ascomycota (99.02 %) was the most abundant fungal phylum. Hanseniaspora was the abundant yeast in the initial stages of fermentation, whereas the population of Saccharomyces increased significantly after 24 h of fermentation. Torulaspora, Lachancea and Starmerella showed their heterogeneous distribution throughout the fermentation. Computational analysis of metagenomes based on KEGG and MetaCyc databases showed different predictive functional profiles such as folate biosynthesis, glutathione metabolism, terpenoids biosynthesis and biosynthesis of amino acids with significant differences between the fresh palm saps and fermenting saps during toddy fermentation.

Wine produced from date palm (Phoenix dactylifera L.) fruits using Saccharomyces cerevisiae X01 isolated from Nigerian locally fermented beverages.

The study focused on the production of wine from date palm fruits (Phoenix dactylifera L.) using a strain of yeast isolated from selected Nigerian locally fermented beverages ('pito', 'brukutu' and palm wine). Seven (7) distinct yeasts were isolated and identified using cultural, microscopy and biochemical tests (temperature tolerance, flocculation, ethanol tolerance, H2S production and killer toxin production and the ability to assimilate and ferment sugars. The yeast isolates were screened using refractometric and spectrophotometric methods to select the isolate with the best ability for wine production. This isolate was molecularly characterized, grown in 1 L of potatoes dextrose broth, freeze dried and used for wine production. The population of yeast, bacteria and the physicochemical analysis of the must were monitored during fermentation. Populations of bacteria in the wine were assessed by standard pour plate count. The proximate content and physicochemical properties of the produced wine before and after ageing, as well as the sensorial quality of the produced wine was determined. All the yeast isolates possessed the ability to flocculate, tolerate ethanol concentration of between 5 and 20% and temperature range of 30-45 °C, produced low concentration of H2S and does not produce killer toxins. A palm wine isolate, identified as Saccharomyces cerevisiae X01 was selected as the best isolate with the most ability for wine production. The total yeast count increases as the period of fermentation progressed while the total viable bacterial count reduced as the fermentation period progressed. There was a significant difference (P < 0.05) in the physicochemical properties of the must during fermentation. At the end of the fermentation, the produced wine had 5.22% and 4.86% ethanol content for S. cerevisiae QA23 and S. cerevisiae X01 respectively. There was no significant difference (P > 0.05) between the proximate and physicochemical compositions of the produced wine before and after ageing using Saccharomyces cerevisiae X01 when compared to the control S. cerevisiae QA23. This study revealed that the Nigerian locally sourced S. cerevisiae X01 can be used as an alternative substrate for industrial scale production of wine with a mild alcoholic content.

Functional Heterologous Expression of Mature Lipase LipA from Pseudomonas aeruginosa PSA01 in Escherichia coli SHuffle and BL21 (DE3): Effect of the Expression Host on Thermal Stability and Solvent Tolerance of the Enzyme Produced.

This study aimed to express heterologously the lipase LipA from Pseudomonas aeruginosa PSA01 obtained from palm fruit residues. In previous approaches, LipA was expressed in Escherichia coli fused with its signal peptide and without its disulfide bond, displaying low activity. We cloned the mature LipA with its truncated chaperone Lif in a dual plasmid and overexpressed the enzyme in two E. coli strains: the traditional BL21 (DE3) and the SHuffle® strain, engineered to produce stable cytoplasmic disulfide bonds. We evaluated the effect of the disulfide bond on LipA stability using molecular dynamics. We expressed LipA successfully under isopropyl ß-d-1-thio-galactopyranoside (IPTG) and slow autoinducing conditions. The SHuffle LipA showed higher residual activity at 45 °C and a greater hyperactivation after incubation with ethanol than the enzyme produced by E. coli BL21 (DE3). Conversely, the latter was slightly more stable in methanol 50% and 60% (t½: 49.5 min and 9 min) than the SHuffle LipA (t½: 31.5 min and 7.4 min). The molecular dynamics simulations showed that removing the disulfide bond caused some regions of LipA to become less flexible and some others to become more flexible, significantly affecting the closing lid and partially exposing the active site at all times.

Aspergillus, Penicillium and Cladosporium species associated with dried date fruits collected in the Perugia (Umbria, Central Italy) market.

A total of 20 dried date samples, chosen as representative among those available on the Perugia (Umbria, Central Italy) market, were analyzed for the possible occurrence of fungal species and related contamination by fungal secondary metabolites. Twenty-six isolates, representative of the total mycobiota, were obtained and morphologically identified as belonging to the genera Aspergillus, Penicillium and Cladosporium. Inside each genus, molecular characterization (by partial sequencing of ITS region and/or ß-tubulin and calmodulin regions for Aspergillus and Penicillium isolates or actin region for Cladosporium isolates) and in vitro mycotoxigenic profile characterization (by LC-MS/MS analysis) showed the presence of the following species: A. flavus, A. tubingensis, P. brevicompactum, P. chrysogenum, P. crustosum, P. glabrum, P. solitum, P. venetum, C. cladosporioides, C. limoniforme and C. halotolerans, with A. tubingensis as the prevalent species and P. crustosum, P. solitum, P. venetum and C. limoniforme first reported here on dates. Date packaging and format showed an effect on the incidence of isolated fungi, with the lowest incidence recovered from whole dates and in hermetic bag packaging. These findings can be useful both for dried dates producers and consumers, guiding them towards choices of packaging and format with a lower risk of mycotoxigenic species presence. However, no fungal metabolites were detected in the dried date samples analyzed, which were therefore regarded as safe for human consumption, underlining the absence of correspondence between fungal isolation and mycotoxin contaminations.

Effect of Trichoderma reesei Degraded Date Pits Supplementation on Growth Performance, Immunoglobulin Levels, and Intestinal Barrier Functions of Broiler Chickens.

BACKGROUND: Date palm (Phoenix dactylifera L.) is a dominant fruit crop in most Arabian countries. Date pits, as a major byproduct which remained after consumption of date flesh, proved to be a valuable source of energy. OBJECTIVES: The impact of degraded date pits (DDP) on growth performance, intestinal bacterial population, and expression profiles of intestinal genes in broilers was determined. Recent patents have been established on DDP from the European patent office (EP2586318B1), Hong Kong patent registry office (HK1184642) and by the United States patent and trademark office (US8968729B2 and US10265368B2). METHODS: Solid-state degradation system (SSD) was used for the preparation of DDP using Trichoderma reesei. One-day-old Brazilian broiler chicks "Cobb 500" were randomly divided into six treatments with six replicates, which consisted of a normal diet containing only corn-soy (control), diet containing corn-soy + (20%, 50g/100Kg oxytetracycline), diet containing corn-soy + 10% (DDP), diet containing corn-soy + 0.2% mannan oligosaccharides (MOS), diet containing corn-soy + 0.1% mannose, and diet containing corn-soy + 0.2% mannose. RESULTS: There were no significant differences in body weight, feed intake, and feed conversion ratio (FCR) in broilers among the treatments. The bacterial count was significantly decreased in 10% DDP diet-fed broilers, 0.2% MOS and antibiotic diet-fed broilers. Immunoglobulin levels in serum and intestinal contents and expression pattern of genes in jejunum were upregulated in 10% DDP and 0.2% MOS diet-fed broilers. CONCLUSION: DDP can be used as an energy source for replacing part of corn, mannan oligosaccharide and also recommended as a potential alternative to antimicrobials in broilers diet.

Overexpression of a Metallothionein 2A Gene from Date Palm Confers Abiotic Stress Tolerance to Yeast and Arabidopsis thaliana.

Although the date palm tree is an extremophile with tolerance to drought and certain levels of salinity, the damage caused by extreme salt concentrations in the soil, has created a need to explore stress-responsive traits and decode their mechanisms. Metallothioneins (MTs) are low-molecular-weight cysteine-rich proteins that are known to play a role in decreasing oxidative damage during abiotic stress conditions. Our previous study identified date palm metallothionein 2A (PdMT2A) as a salt-responsive gene, which has been functionally characterized in yeast and Arabidopsis in this study. The recombinant PdMT2A protein produced in Escherichia coli showed high reactivity against the substrate 5'-dithiobis-2-nitrobenzoic acid (DTNB), implying that the protein has the property of scavenging reactive oxygen species (ROS). Heterologous overexpression of PdMT2A in yeast (Saccharomyces cerevisiae) conferred tolerance to drought, salinity and oxidative stresses. The PdMT2A gene was also overexpressed in Arabidopsis, to assess its stress protective function in planta. Compared to the wild-type control, the transgenic plants accumulated less Na+ and maintained a high K+/Na+ ratio, which could be attributed to the regulatory role of the transgene on transporters such as HKT, as demonstrated by qPCR assay. In addition, transgenic lines exhibited higher chlorophyll content, higher superoxide dismutase (SOD) activity and improved scavenging ability for reactive oxygen species (ROS), coupled with a better survival rate during salt stress conditions. Similarly, the transgenic plants also displayed better drought and oxidative stress tolerance. Collectively, both in vitro and in planta studies revealed a role for PdMT2A in salt, drought, and oxidative stress tolerance.

Consistent bacterial selection by date palm root system across heterogeneous desert oasis agroecosystems.

Highly productive conventional agroecosystems are spatially embedded in resource-homogeneous systems and count on generally nutrient-rich soils. On the contrary, desert oases are isolated, the soil is relatively poor, but yet productivity is similar to conventional agroecosystems. Soil dominates over plant as the main factor shaping root-associated microbiomes in conventional agroecosystems. We hypothesize that in desert oasis, the environmental discontinuity, the resource paucity and limited microbial diversity of the soil make the plant a prevailing factor. We have examined the bacterial communities in the root system of date palm (Phoenix dactylifera), the iconic keystone species of the oases, grown in heterogeneous soils across a broad geographic range (22,200 km2 surface area) of the Sahara Desert in Tunisia. We showed that, regardless of the edaphic conditions and geographic location, the plant invariably selects similar Gammaproteobacteria- and Alphaproteobacteria-dominated bacterial communities. The phylogeny, networking properties and predicted functionalities of the bacterial communities indicate that these two phyla are performing the ecological services of biopromotion and biofertilization. We conclude that in a desert agroecosystem, regardless of the soil microbial diversity baseline, the plant, rather than soil type, is responsible of the bacterial community assembly in its root systems, reversing the pattern observed in conventional agroecosystem.

Bioactive coatings from nano-biopolymers/plant extract composites for complete protection from mycotoxigenic fungi in dates.

BACKGROUND: Contamination of date fruit with mycotoxigenic fungi is a hazardous threat. The present study investigated the effectiveness of natural derivatives for controlling this. Chitosan (Cts) was produced from Aspergillus niger mycelia and characterized and then nanochitosan (NCt) particles were synthesized from fungal Cts. Edible-coating films were formulated based on Cts, NCt, pomegranate peel extract (PPE) and their composites and these were evaluated as antifungal materials against mycotoxigenic fungi, Aspergillus flavus, Aspergillus ochraceus and Fusarium moniliforme. RESULTS: The Cts produced had 88.7% deacetylation, a molecular weight of 24.5 kDa and 98% solubility in diluted acetic acid, whereas the particle diameters of synthesized NCts ranged from 35 to 65 nm. The inhibition zone assay emphasized the antifungal effectiveness of the entire coating films. The most effective agent for preparing edible film was the blend of NCt + PPE followed by Cts + PPE based films. The practical application of antifungal films for date decontamination with respect to mycotoxigenic fungi demonstrates that the films were very effective for controlling the entire fungal strain and preventing growth on the fruits. CONCLUSION: The NCt + PPE and Cts + PPE based films were found to be the most effective because they could completely eliminate the growth of any fungal spore on date fruit after 48 h from the coating experiment. © 2019 Society of Chemical Industry.

Molecular Identification and Disease Management of Date Palm Sudden Decline Syndrome in the United Arab Emirates.

Date palm orchards suffer from serious diseases, including sudden decline syndrome (SDS). External symptoms were characterized by whitening on one side of the rachis, progressing from the base to the apex of the leaf until the whole leaf dies; while the internal disease symptoms included reddish roots and highly colored vascular bundles causing wilting and death of the tree. Although three Fusarium spp. (F. oxysporum, F. proliferatum and F. solani) were isolated from diseased root samples, the fungal pathogen F. solani was associated with SDS on date palm in the United Arab Emirates (UAE). Fusarium spp. were identified based on their cultural and morphological characteristics. The internal transcribed spacer regions and large subunit of the ribosomal RNA (ITS/LSU rRNA) gene complex of the pathogens was further sequenced. Pathogenicity assays and disease severity indices confirm the main causal agent of SDS on date palm in the UAE is F. solani. Application of Cidely® Top (difenoconazole and cyflufenamid) significantly inhibited the fungal mycelial growth in vitro and reduced SDS development on date palm seedlings pre-inoculated with F. solani under greenhouse conditions. This is the first report confirming that the chemical fungicide Cidely® Top is strongly effective against SDS on date palm.

Date Palm Trees Root-Derived Endophytes as Fungal Cell Factories for Diverse Bioactive Metabolites.

Endophytic fungi of healthy and brittle leaf diseased (BLD) date palm trees (Phoenix dactylifera L.) represent a promising source of bioactive compounds with biomedical, industrial, and pharmaceutical applications. The fungal endophytes Penicillium citrinum isolate TDPEF34, and Geotrichum candidum isolate TDPEF20 from healthy and BLD date palm trees, respectively, proved very effective in confrontation assays against three pathogenic bacteria, including two Gram-positive bacteria Bacillus thuringiensis (Bt) and Enterococcus faecalis (Ef), and one Gram-negative bacterium Salmonella enterica (St). They also inhibited the growth of three fungi Trichoderma sp. (Ti), Fusarium sporotrichioides (Fs), Trichoderma sp. (Ts). Additionally, their volatile organic compounds (VOCs) were shown to be in part responsible for the inhibition of Ti and Ts and could account for the full inhibition of Fs. Therefore, we have explored their potential as fungal cell factories for bioactive metabolites production. Four extracts of each endophyte were prepared using different solvent polarities, ethanol (EtOH), ethyl acetate (EtOAc), hexane (Hex), and methanol (MetOH). Both endophyte species showed varying degrees of inhibition of the bacterial and fungal pathogens according to the solvent used. These results suggest a good relationship between fungal bioactivities and their produced secondary metabolites. Targeting the discovery of potential anti-diabetic, anti-hemolysis, anti-inflammatory, anti-obesity, and cytotoxic activities, endophytic extracts showed promising results. The EtOAc extract of G. candidum displayed IC50 value comparable to the positive control diclofenac sodium in the anti-inflammatory assays. Antioxidant activity was evaluated using α,α-diphenyl-ß-picrylhydrazyl (DPPH), ß-carotene bleaching, reducing power (RP), and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulphonique) (ABTS) radical scavenging assays. The findings revealed strong anti-oxidant power with an IC50 of 177.55 µg/mL for G. candidum EtOAc extract using DPPH assay, probably due to high polyphenol and flavonoid content in both fungal extracts. Finally, LC-HRMS (Liquid Chromatography­High Resolution Mass Spectrometry) and GC-MS (Gas Chromatography­Mass Spectrometry) analysis of G. candidum and P. citrinum extracts revealed an impressive arsenal of compounds with previously reported biological activities, partly explaining the obtained results. Finally, LC-HRMS analysis indicated the presence of new fungal metabolites that have never been reported, which represent good candidates to follow for the discovery of new bioactive molecules.

Effect of edible co-polymers coatings using γ-irradiation on Hyani date fruit behavior during marketing.

The present work introduces a preparation of coating fruits film from natural biodegradable materials with evaluation of its efficiency in keeping the quality of fresh date fruits. Triple blend (Tb) which involved PVA, chitosan (Cs) and tannic (TA) acids was studied in preservation of Rutab (Hyani) date. Antimicrobial characters besides decay of fruits during a cold storage were determined. The blend solutions were exposed to the γ-irradiation (5.0 to 20 kGy) before casting or use. The effects of polymer composition and irradiation dose on the mechanical and thermo-mechanical properties were studied. The obtained results showed that γ-irradiation and the addition of tannic acid (TA) increased the mechanical properties of the films and the shelf-life of Rutab (Hyani) date during the marketing period (12 ±â€¯2 °C, 98%, RH) from one week to one month of marketing period for consumers with accepted freshness and quality.