Egyptian Soil Research Articles

Isolation and characterization of halophilic Bacillus thuringiensis from local Egyptian sites and their potential against Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)

BackgroundBacillus thuringiensis (Bt) serves as a peculiar soil microbe that is Gram-positive, rod-shaped, spore-forming, and aerobic facultative. It endures across a range of conditions and has been demonstrated to be an effective biological pest control agent against several insect pests. The main objective of the study is to isolate and recognize Bt bacteria from saline environments in Egyptian soil for biological surveillance uses.ResultsIsolates three, four, five, ten, eleven, twelve, and thirteen were found to be moderately tolerant, while isolate eight showed highly tolerant, but isolate six was found to be borderline extreme halophile. On the other hand, the other isolates showed extreme halophiles. To find out the presence of crystals, a scanning electron microscope was carried out and the result showed that the crystals ranged from spherical to bi-pyramidal spherical. Molecular analysis was carried out using universal primers to confirm the presence of cry genes. The results showed that 84.6% of the isolates contain cry seven and eight, whereas cry one and four are distributed by 92.3%. Cry two genes were found to be 100 percent in all tested and isolated cultures. Cry genes were present and distribution among isolated was detected using gene-specific primers. cry3Ba1 and cry8B showed the lowest and equal distribution among the isolates, while the cry2Ab2gene frequency distribution was (84.6%) among isolated cultures. Around six cry genes were found to be absent in all isolated cultures. The bioinsecticidal activity and bioassays were carried out to check the potential effect of halophilic Bt isolates against 1st instar larvae of the Fall Armyworm (FAW) Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae). Mortality was calculated after infecting S. frugiperda with thirteen Bt isolates. The most virulent Bt isolate was isolate 7, followed by isolate 10, with LC50 values of 9.542 × 107 spores/ml and 1.289 × 108 spores/ml, respectively, after 72 h. Morphological traits of the larvae were carried out, to check the effect of Bt isolates as a biological control against the FAW.ConclusionTo protect and enhance the sustainability of field crops and vegetables, especially in new high salinity lands, from disease-causing insects such as FAW, it is necessary to identify new strains of Bt from these saline lands. In this field, local isolates of Bt from several regions in Egypt known for their high levels of salinity were documented and showed an effective bioinsecticide on FAW larvae.

Evaluation of a Novel Streptomyces avermitilis Strain from Egyptian Soil for Biological Control of Tetranychus urticae in Greenhouse Cucumber Plantations

Background: Infestation in greenhouse cucumber with the two-spotted spider mite (Tetranychus urticae Koch) commonly causes severe damage to crop quality and quantity and increases crop production costs. Objective: This study was conducted to investigate the efficacy of high-abamectinproducing isolates of S. avermitilis against T. urticae-infested cucumber and to assess their impact on biochemical stress markers in these vegetables. Methods: In this study, 72 non-antagonistic Streptomyces were isolated from rhizospheric soil samples collected from eight different locations in Egypt and screened for their ability to produce the secondary metabolite, abamectin Results: The screening process identified two potent abamectin-producing isolates, EW8 and T2, which produced 42.7 and 29.6 μg/L abamectin, respectively, as confirmed by LC-MS/MS analysis. According to DNA sequence analysis of the 16S rRNA gene, these two isolates belong to the species S. avermitilis. The acaricidal activity of either culture suspensions of S. avermitilis strains WE8 and T2, or their extracts containing abamectin, against the mobile stages and egg hatchability of T. urticae was evaluated in the laboratory and the greenhouse. Data on the mortality among the examined female mites and the reduction in their number of eggs point out a potential acaricidal activity of the examined strains of S. avermitilis and their extracts containing abamectin against T. urticaes. Furthermore, the extracts containing abamectin from these two S. avermitilis strains induced oxidative stress in the infested cucumber plants by T. urticaes, as indicated by increased levels of malondialdehyde (MDA). However, the levels of MDA in T. urticae-infested cucumber plants varied depending on the strain and the specific abamectin crude extract used. Conclusion: S. avermitilis strains T2 or WE8, or their crude extract could be applied in greenhouse cucumber plantations to combat red mite infestation (Fig. 1).

Isolation of Polyhydroxybutyrate Microbial Producer from Local Egyptian Soil

Isolation of Polyhydroxybutyrate Microbial Producer from Local Egyptian Soil

Climate Change and the Possibility of Tea Production in the Egyptian Soils

Climate Change and the Possibility of Tea Production in the Egyptian Soils

Unlocking the Potential of Plant Growth-Promoting Rhizobacteria to Enhance Drought Tolerance in Egyptian Wheat (Triticum aestivum)

Plant growth-promoting rhizobacteria (PGPRs) represent a promising strategy for enhancing plant resilience and yields under drought-stress conditions. This study isolated and characterized PGPR from wheat rhizosphere soil in Egypt. Four PGPR strains were evaluated for an array of plant growth-promoting traits, including IAA production, biofilm formation, siderophore production, nitrogen fixation, ACC deaminase activity, phosphate solubilization, and antagonistic potential. Molecular identification via 16S rRNA sequencing classified three isolates (MMH101, MMH102, and MMH103) within the Bacillus genus and one isolate (MMH104) as Myroides sp. Greenhouse experiments examined the effects of PGPR inoculation on the drought-stressed Egyptian wheat cultivar, Gimmeza-9. Wheat plants inoculated with PGPR isolates showed dramatic improvements in growth parameters and stress tolerance indicators compared to non-inoculated controls when subjected to a 10-day drought period, with Bacillus rugosus (MMH101) inoculation resulting in increases of 61.8% in fresh biomass, 77.2% in dry biomass, 108.5% shoot length, and 134.9% root length. PGPR treatments also elevated the chlorophyll and proline content while reducing malondialdehyde levels. The findings demonstrate the effectiveness of PGPR inoculation in enhancing the morphology, physiology, and drought stress resilience of wheat. Isolated PGPR strains hold promise as biofertilizers for improving cereal productivity under water-deficit conditions.

Alpha-sitosterol: a new antiviral agent produced by Streptomyces misakiensis and its potential activity against Newcastle disease virus

BackgroundNewcastle Disease Virus (NDV) causes severe economic losses in the poultry industry worldwide. Hence, this study aimed to discover a novel bioactive antiviral agent for controlling NDV. Streptomyces misakiensis was isolated from Egyptian soil and its secondary metabolites were identified using infrared spectroscopy (IR), gas chromatography–mass spectrometry (GC–MS), and nuclear magnetic resonance (NMR) spectroscopy. The inhibitory activity of bioactive metabolite against NDV were examined. Three experimental groups of 10-day-old specific pathogen-free embryonated chicken eggs (SPF-ECEs), including the bioactive metabolite control group, NDV control positive group, and α-sitosterol and NDV mixture-treated group were inoculated.Resultsα-sitosterol (Ethyl-6-methylheptan-2-yl]-10,13-dimethyl-dodecahydro-1H-cyclopenta[a]phenanthren-3-ol), a secondary metabolite of S. misakiensis, completely inhibited hemagglutination (HA) activity of the NDV strain. The HA activity of the NDV strain was 8 log2 and 9 log2 for 0.5 and 0.75% RBCs, respectively. The NDV HA activity for the two concentrations of RBCs was significantly (P < 0.0001) inhibited after α-sitosterol treatment. There was a significant (P < 0.0001) decrease in the log 2 of HA activity, with values of − 0.500 (75%, chicken RBCs) before inoculation in SPF-ECEs and − 1.161 (50%, RBCs) and − 1.403 (75%, RBCs) following SPF-ECE inoculation. Compared to ECEs inoculated with NDV alone, the α-sitosterol-treated group showed improvement in histological lesion ratings for chorioallantoic membranes (CAM) and hepatic tissues. The CAM of the α-sitosterol- inoculated SPF-ECEs was preserved. The epithelial and stromal layers were noticeably thicker with extensive hemorrhages, clogged vasculatures, and certain inflammatory cells in the stroma layer in the NDV group. However, mild edema and inflammatory cell infiltration were observed in the CAM of the treated group. ECEs inoculated with α-sitosterol alone showed normal histology of the hepatic acini, central veins, and portal triads. Severe degenerative alterations, including steatosis, clogged sinusoids, and central veins, were observed in ECEs inoculated with NDV. Mild hepatic degenerative alterations, with perivascular round cell infiltration, were observed in the treated group.ConclusionTo the best of our knowledge, this is the first study to highlight that the potentially bioactive secondary metabolite, α-sitosterol, belonging to the terpene family, has the potential to be a biological weapon against virulent NDV. It could be used for the development of innovative antiviral drugs to control NDV after further clinical investigation.

Nodule formation efficiency evaluation and nifH gene detection of Rhizobium species isolated from Egyptian soil

Nodule formation efficiency evaluation and nifH gene detection of Rhizobium species isolated from Egyptian soil

Lytic phages isolated from Egypt for biocontrol of potato soft rot caused by Pectobacterium carotovorum

Pectobacterium carotovorum is an economically important phytopathogen causing destructive bacterial soft rot disease in many ornamental plants and fruit and vegetable crops worldwide, including potato. Phage therapy is a promising and environmentally safe alternative to combat bacterial diseases either in the field or during storage. In this study, we characterized two novel P. carotovorum-specific phages, designated PcaP1EGY and PcaP2EGY, isolated from soil in Egypt. We also sequenced the genomes of the two phages, which are the first two complete genome sequences determined for P. carotovorum-infecting podoviruses from Egypt. Phages PcaP1EGY and PcaP2EGY have a high phage titer of 1012 PFU/mL and growth characteristics of an exclusively lytic life cycle. Both phages displayed specificity to and visible lysis activity against all four tested strains of P. carotovorum. They both had a latent period of 30 min and a high burst size of approximately 599 PFU/infected cell for PcaP1EGY and 570 for PcaP2EGY. Additionally, they exhibited remarkable survivability under a wide range of pH, temperature, salt concentration and UV exposure conditions. Both phages, when used alone or in combination, significantly reduced in vitro growth of P. carotovorum after 4 h at all tested multiplicity of infection. Phages PcaP1EGY and PcaP2EGY offered significant protection for both potato tubers and potato plants against soft rot disease caused by P. carotovorum in both our tuber maceration test and greenhouse pot experiment as compared to tubers/plants inoculated with P. carotovorum without receiving any phage treatment. Our results suggest that phages PcaP1EGY and PcaP2EGY have great biocontrol potential against potato soft rot disease caused by P. carotovorum either in the field or during storage after harvest.

Modeling study of adsorption isotherms of chlorantraniliprole and dinotefuran on soil

Knowledge of pesticide adsorption characteristics is essential to predict their behavior in soil. The adsorption equilibrium isotherms of two insecticides chlorantraniliprole (CAP) and dinotefuran (DNF) on two common Egyptian soil types, clay loam and sandy loam were studied and modeled. To predict the adsorption isotherms and to determine the adsorption parameters, ten isotherm models: Langmuir (five linear forms), Freundlich, Temkin, Dubinin-Radushkevich, Elovick, Fowler-Guggenheim, Kiselev, Jovanoic, Harkins-Jura, and Halsey were applied on experimental data. The results revealed that the adsorption isotherm models fitted the data in the order of Halsey &gt; Freundlich &gt; Jovanoic &gt; Langmuir isotherme. The models of Harkins-Jura, Elovich, Temkin, and Fowler-Guggenheim are not applicable to predict the adsorption isotherms of the tested insecticides. In order to determine the best-fit isotherm, the correlation coefficient (R2), comparing the experimental (exp) and calculated (cal) adsorption data, and a normalized standard deviation (Δg%) were used to evaluate the data. Therefore, the isotherm models Halsey and Freundlich could be used to predict the adsorption characteristics of CAP and DNF in the common Egyptian soil types, clay loam and sandy loam. Consequently, the mathematical models Halsey, Freundlich, and Jovanoic can describe the fate of CAP and DNF and can be used to control Egyptian soil contamination.

Promising Egyptian soil bacterial isolates for hydrocarbon waste biodegradation: petroleum wax

Promising Egyptian soil bacterial isolates for hydrocarbon waste biodegradation: petroleum wax

Aspergillus niger; Aspergillus terreus HDJZ-ZWM and Paecilomyces variotii as polyextremophilic fungi isolated from Egyptian soil.

Aspergillus niger; Aspergillus terreus HDJZ-ZWM and Paecilomyces variotii as polyextremophilic fungi isolated from Egyptian soil.

Experimental and finite-element study for improvement of the swelling characteristics of expansive soil in Egypt using coarse soil

Experimental and finite-element study for improvement of the swelling characteristics of expansive soil in Egypt using coarse soil

Identification and molecular characterization of arginine deiminase-producing bacteria in Egyptian soil from various soil environments

Identification and molecular characterization of arginine deiminase-producing bacteria in Egyptian soil from various soil environments

The application of deep neural networks for the prediction of California Bearing Ratio of road subgrade soil

California Bearing Ratio (CBR) of the subgrade soil is one of the essential values for the design and construction of the asphalt pavement of highway projects. However, the estimation of the CBR value through laboratory tests is time-consuming and labor-intensive. Thus, this study focuses on providing artificial neural network (ANN) prediction models that can be efficiently used for the prediction of the CBR value of the subgrade soil in Egypt from the grain size distribution, Atterberg limits, and compaction parameters. 240 ANNs with different hyperparameters are investigated in order to optimize the hyperparameters so that the final chosen ANN can provide accurate results. The analysis shows that the deep neural networks outperform the shallow ANNs. Finally, comparing the performance of the ANNs with the traditional multiple linear regression (MLR) shows that ANNs outperform the MLR models as the ANNs have much better performance and can generate highly accurate predictions.

Enhancing the Availability of Potassium in New Egyptian Soils using Biochar Produced from Olive Stone Waste

The warming phenomenon is one of the most difficult challenges of the times. Agricultural waste decomposition contributes to global warming due to the increase in greenhouse gases. Carbon sequestering is used to reduce greenhouse gases to mitigate the warming phenomenon. Applying biochar is one of the most important tools for sequestering carbon in the soil for hundreds to thousands of years. Paper aims to produce olive stone biochar (OSB) and apply it to soils to study its effect on soil properties and the status of K (Quantity/Intensity of K). Biochar was produced from olive stone waste at 650°C and applied at rates of 0, 1, 2, and 5% in two investigated soils (sandy and calcareous) to study its effects on soil properties and growth of the wheat plants. Results of biochar analysis indicated that it possesses several functional groups and essential elements (N, P, and K), a large surface area (394.25 m2 g-1), and an average fine diameter (0.8 µm). The application of OSB improved several soil properties, including water holding capacity, %porosity, bulk density, cation exchange capacity, and availability of some nutrients, especially potassium. Additionally, it increased the soluble-K and ammonium acetate (NH4OAc-K) levels in the investigated soils. The potential buffering capacity of K (PBCK), activity ratio of K (ARK), and labile K (KL) were also enhanced. Moreover, OSB application improved the wheat plant’s height, root depth, dry matter, and NPK content. Therefore, we concluded that biochar is beneficial for sequestering carbon for the long-term and improving soil fertility.

Biosynthesized silver nanoparticles (Ag NPs) from isolated actinomycetes strains and their impact on the black cutworm, Agrotis ipsilon

Nanomaterials have been produced with the use of bio-nanotechnology, which is a low-cost approach. Currently, research is being conducted to determine whether actinomycetes isolated from Egyptian soil can biosynthesize Ag nanoparticles (Ag NPs) and characterized by using the following techniques: Transmission electron microscopy (TEM), Dynamic light scattering (DLS), Fourier transforms infrared (FT-IR), Energy-dispersive X-ray spectroscopy (EDX), UV–Vis spectroscopy and X-ray diffraction (XRD). The most promising actinomycetes isolate were identified, morphologically, biochemically, and molecularly. Streptomyces avermitilis Azhar A.4 was found to be able to reduce silver metal nanoparticles from silver nitrate in nine isolates collected from Egyptian soil. Toxicity of biosynthesized against 2nd and 4th larval instar of Agrotis ipsilon (Hufn.) (Lepidoptera: Noctuidae) was estimated. In addition, activity of certain vital antioxidant and detoxifying enzymes as well as midgut histology of treated larvae were also investigated. The results showed appositive correlations between larval mortality percentage (y) and bio-AgNPs concentrations (x) with excellent (R2). The 4th larval instar was more susceptible than 2nd larval instar with LC50 (with 95% confirmed limits) =8.61 (2.76–13.89) and 26.44(13.25–35.58) ppml−1, respectively of 5 days from treatment. The initial stages of biosynthesized AgNps exposure showed significant increases in carboxylesterase (CarE) and peroxidases (PODs) activity followed by significant suppression after 5 days pos-exposure. While protease activity was significantly decreased by increasing time post-exposure. Midgut histology showed abnormality and progressive damage by increasing time post exposure leading to complete destruction of midgut cells after 5 days from exposure. These results make biosynthesized AgNPs an appropriate alternative to chemical insecticide in A. ipsilon management.

The production of biosurfactants by local fungi isolated from Egyptian soil

One of the most important sources of biomolecules is soil fungi which have unique metabolic and physiologic features. The present study investigates the ability of local fungi isolated from Egyptian soil to produce biosurfactants. The oil displacement area (ODA) test was used to study the effect of three different environmental conditions (pH, temperature, and salinity) on the stability of produced biosurfactants. The study aimed also to reuse four vegetable oils (sunflower oil, olive oil, waste frying oil, and corn oil), which are widely used in the daily activities of the Egyptians, for the enhancement of the production and activity of biosurfactants by fungal isolates. The highest production of biosurfactants was observed by Aspergillus wentii, Aspergillus flavus, and Fusarium sp. The results showed that most of the biosurfactants were stable at a wide range of temperatures, alkaline pH, and high salinity. Sunflower oil followed by waste frying oil showed the highest enhancement effects. Olive oil showed moderate enhancement while corn oil showed the lowest effect. Thus, it can be concluded local soil fungi are considered a promising potential source to produce biosurfactants. It can be concluded that our study is the first study that mentioned the ability of A. wentii isolated from the soil as a biosurfactant producer.

The Brazilian archaeological program in Egypt: the first six years on TT123: assembling the puzzle

Created in 2015, the Brazilian Archaeological Program in Egypt (BAPE) develops transversal and participatory research on Egyptian soil. Since 2016, BAPE has been developing, together with the Egyptian government, an excavation project for Theban Tomb 123, located in Sheikh Abdel Qurna, Luxor, known as the Amenemhet Project. Tomb 123 served as a burial ground during the Pharaonic period and is currently a modern residence for Qurnawi families. This paper presents the first results of the research conducted at the site, offering a first interpretation based on the data collected so far, from an archaeological, historical and ethnographic perspective.

Identification of Antimicrobial Metabolites from the Egyptian Soil-Derived Amycolatopsis keratiniphila Revealed by Untargeted Metabolomics and Molecular Docking.

Actinomycetes are prolific producers of bioactive secondary metabolites. The prevalence of multidrug-resistant (MDR) pathogens has prompted us to search for potential natural antimicrobial agents. Herein, we report the isolation of rare actinobacteria from Egyptian soil. The strain was identified as Amycolatopsis keratiniphila DPA04 using 16S rRNA gene sequencing. Cultivation profiling, followed by chemical and antimicrobial evaluation of crude extracts, revealed the activity of DPA04 ISP-2 and M1 culture extracts against Gram-positive bacteria. Minimum inhibitory concentrations (MIC) values ranged from 19.5 to 39 µg/mL. Chemical analysis of the crude extracts using ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF) led to the identification of 45 metabolites of different chemical classes. In addition, ECO-0501 was identified in the cultures with significant antimicrobial activity. Multidrug resistance in Staphylococcus aureus is reported to be related to the multidrug efflux pump (MATE). ECO-0501 and its related metabolites were subjected to molecular docking studies against the MATE receptor as a proposed mechanism of action. ECO-0501 and its derivatives (AK_1 and N-demethyl ECO-0501) had better binding scores (-12.93, -12.24, and -11.92 kcal/mol) than the co-crystallized 4HY inhibitor (-8.99 kcal/mol) making them promising candidates as MATE inhibitors. Finally, our work established that natural products from this strain could be useful therapeutic tools for controlling infectious diseases.

A comparative technical study for estimating seeped water from irrigation canals in the Middle Egypt (Case study: El-Sont branch canal network)

Integrating with the national project of irrigation canal lining in the Egyptian countryside, the present study is introduced. The study presents a technical comparison of differential equations that are usually used for estimating the seeped water from the earthen irrigation canals. The quantities of irrigation water that are lost due to seepage are great enough to decrease the wide gap between the needed and available water quantities that Egypt seriously suffers from. So, the accurate estimation of the seeped water quantities is very important. The study aims to select the suitable seepage equations for the Egyptian soil, climate, and the currently used distributed irrigation system. It is also to assess the understudy network by estimating the lost water quantities due to seepage by using the designed water sections’ dimensions and comparing the results with those obtained using the existing field dimensions. In addition, to determining the agricultural area that can be added to the current served area after preserving such great quantities. From the Assiut countryside, the El-Sont canal and its network were chosen to be a case study. After a careful technical reading of the seepage equations that researchers introduced previously, the closest relationships to the case study were used. Results indicated that using the suggested relationship by Nazir Ahmed and the Indian equation, gave the maximum seepage quantities for the entire El-Sont canal network with about 21.5% of the total canal head discharge. Most of this lost water can be saved due to the implementation of the national project for irrigation canal lining. This large amount of preserved water can be used to irrigate 15% of the currently served area.