Optimization of some experimental growth conditions for biosilver nanoparticles synthesized using supernatant of Bacillus pseudomycoides MT32 were studied. The optimized growth conditions were obtained at 2mM silver nitrate concentration, 30°C temperature degree, 6.5 pH level, 40 h incubation time, 140 rpm agitation speed, medium type was Nutrient broth (NB) and supernatant and silver nitrate ratio was 20:30. Characterizations of the produced nanoparticles were done using seven advanced instruments. The ultraviolet-visible spectrashowed an absorption peak at 420 nm. Transmis sion Electron Microscopy (TEM) showed that the mean diameter of the formed SNPs was 25 to 43 nm. Powder X-ray diffraction (XRD) revealed that the particles are crystalline in nature, with a spherical structure and their size ranges from 32 to 86 nm. From dynamic light scattering (DLS) and Zeta potential analyses, the average SNPs size was 63.39 nm and the Zeta potential was −18.3 mV. Energy-dispersive X-ray spectroscopy (EDX) exhibited strong signal in the silver region and confirmed the formation of SNPs. The SNPs also exhibited traces of agglomeration. From antifungal studies in vitro, the produced SNPs are capable of suppression, in different extents, of ten commercially plant pathogenic fungi and the recorded values of MIC and MFC were varied due to the type of fungi used, and they were in a range of 70-90, and 75-100 µg / l, respectively. The antifungal activity of the SNPs produced by Bacillus pseudomycoides MT32 is useful in solving different problems in crops production as well as in animals' nutrition.

The present study demonstrates a positive correlation between zinc metal tolerance ability of an isolated fungi and their potential for the synthesis of zinc oxide nanoparticles (ZnO-NPs). A total of 5 fungal cultures were isolated from the rhizospheric soils of plants naturally growing at Sharkia Governorate in Egypt and identified based on morphological characteristics. These isolates are belongs to Aspergillus niger (An), Aspergillus tubulin (At), Aspergillus fumigatus(Af), Penicillium citrinum (Pc) and Fusarium oxysporum (Fo). These isolates were used in the synthesis of zinc-oxide nanoparticles (An-ZnO-NPs, At-ZnO-NPs, Af-ZnO-NPs, Pc-ZnO-NPs and Fo-ZnO-NPs) using Zinc sulfate as the precursor compared to the references strains of A. tubingensis Mosseray AUMC No.6915, A. fumigatus Fresenius AUMC No.48 and A. terreus Thom AUMC No.75. Aspergillus and Fusarium isolates have been shown to have a high zinc metal tolerance ability and a potential for extracellular synthesis of ZnO nanoparticles under ambient conditions. The synthesized ZnO-NPs were tested by the detection of a notable absorption peak at 285 to 296 nm, appearing in UV-Vis spectra due to surface-plasmon-resonance. Transmission electron microscope (TEM) results revealed that An-ZnO-NPs, At-ZnO-NPs, Af-ZnO-NPs, Pc-ZnO-NPs and Fo-ZnO-NPs exhibited a crystalline structure with hexagonal wurtzite shape (30-100 nm size). ZnO nanoparticles exhibited excellent antibacterial activity against tested Gram-positive and Gram-negative bacteria. The ZnO nanoparticles showed better antibacterial activity against Staphylococcus. aureus, Listeria. monocytogenes and Bacillus cereus compared to Salmonella enterica, Escherichia coli and Pseudomonas aerogenosa. The effectiveness of inhibition of the microbial biofilms formation of S.aureus, L. monocytogenes and B. cereus compared to S. enterica, E. coli and P. aerogenosa was analyzed at a concentration of 100 μg/ ml.

Phenols are very soluble in water; as a result, they can pollute a massive volume of fresh water, wastewater, groundwater, oceans, and soil, negatively affecting plant germination and animal and human health. For the detoxification and bioremediation of phenol in wastewater, phenol biodegradation using novel bacteria isolated from sewage sludge was investigated. Twenty samples from sewage sludge (SS) were collected, and bacteria in SS contents were cultured in the mineral salt agar (MSA) containing phenol (500 mg/L). Twenty colonies (S1 up to S20) were recovered from all the tested SS samples. The characteristics of three bacterial properties, 16S rDNA sequencing, similarities, GenBank accession number, and phylogenetic analysis showed that strains S3, S10, and S18 were Pseudomonas aeruginosa, Klebsiella pneumoniae, and Klebsiella variicola, respectively. P. aeruginosa, K. pneumoniae, and K. variicola were able to degrade 1000 mg/L phenol in the mineral salt medium. The bacterial strains from sewage sludge were efficient in removing 71.70 and 74.67% of phenol at 1000 mg/L within three days and could tolerate high phenol concentrations (2000 mg/L). The findings showed that P. aeruginosa, K. pneumoniae, and K. variicola could potentially treat phenolic water. All soybean and faba bean seeds were germinated after being treated with 250, 500, 750, and 1000 mg/L phenol in a mineral salt medium inoculated with these strains. The highest maximum phenol removal and detoxification rates were P. aeruginosa and K. variicola. These strains may help decompose and detoxify phenol from industrial wastewater with high phenol levels and bioremediating phenol-contaminated soils.

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Nanotechnology and nanoparticles (NPs) researches have attracted a lot of interest in recent decades, and there is growing attention to find more effective ways for their synthesis. The use of biological approach, (using various microorganisms), as bio-nanofactories provides a clean and promising alternative process for the fabrication of silver nanoparticles. This study confirmed the production of silver nanoparticles (AgNPs) by a cost effective, safe and environment-friendly technique using silver nitrate and supernatants of the bacterium Bacillus subtilis ssp spizizenii MT5 as a bio reducing agent. Supernatants of the tested microbe growing on nutrient broth (NB) were used for fabrication of AgNPs. Some parameters of optimization i.e., incubation time, silver nitrate concentration, mixing ratio of culture supernatant and silver nitrate, media type, temperature degree and pH level were studied. The biosynthesis of AgNPs in the cell extract filtrate was confirmed and characterized by biophysical methods using the advanced available instruments. The determined conditions for the bioinspired synthesis of AgNPs revealed that incubation time was 40 h, silver nitrate concentration was 3mM, supernatant and silver nitrate ratio was 1:4, medium type was nutrient broth (NB), agitation speed was 160 rpm, temperature degree was 35°C and pH level was 7. Characterizations of the produced bio silver nanoparticles were done using the advanced available methods. The ultraviolet-visible spectrum showed an absorption peak at 420 nm. Transmission electron microscopy (TEM) showed that the mean diameter of the formed AgNPs was 38 to 49 nm. Powder X-ray diffraction (XRD) showed that the particles are crystalline in nature, with a facecentered spherical structure. Dynamic light scattering (DLS) and Zeta potential analysis showed that the average AgNPs size was 31.42 nm and the zeta potential was-20.8mV, Fourier Transform Infrared Spectroscopy analysis (FT-IR) confirmed the presence of elemental silver and the dual function of biomolecule responsible for the bio reduction and stabilization of AgNPs in the reaction mixtures. The scanning electron microscopy (SEM) micrograph indicated that produced AgNPs are spherical in shape. However, it also showed an indeterminate morphology. Energy-dispersive X-ray spectroscopy (EDX) exhibited strong signal in the silver region which confirms the formation of AgNPs.

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This study aimed to isolate, purify, and identify some bacteria from different sources known to be contaminated with pesticides and evaluate their ability to degrade two important pesticides, chlorantraniliprole (CAP), and flubendiamide (FBD). In our study, six isolates showed maximum growth in the presence of CAP and FBD in the growth media as a sole carbon source. The isolates were purified and then identified by biochemical and morphological tests, MALD-TOF-MS, and 16S rRNA techniques, as Bacillus subtilis subsp. subtilis AZFS3, Bacillus pumilus AZFS5, Bacillus mojavensis AZFS15, Bacillus paramycoides AZFS18, Pseudomonas aeruginosa KZFS4, and Alcaligenes aquatilis KZFS11. The degradation ability of studied bacterial strains against pesticides was estimated under different conditions (temperatures, pH, salt, and incubation time). The results reveal that the optimal conditions for all bacterial strains’ growth were 30–35 °C, pH 7.0, 0.0–0.5% NaCl, and an incubation period of 11 days at 150 rpm in the presence of diamide insecticides at 50 mg/L. The capacity of six bacterial strains of CO2 production and degradation ability against various diamide pesticides and other pesticide groups (Profenofos, Cypermethrin, Carbofuran, and Malathion) were evaluated. The results show that the Pseudomonas aeruginosa KZFS4 (LC599404.1) strain produced the highest CO2 content, about 1.226 mg CO2/16 day, with efficacy in the biodegradation of FBD-CAP (78.6%), while the absorbance of bacterial growth (OD 600) on various pesticides ranged from 1.542 to 1.701. Additionally, Consortium-(No. 3)-mix-6-strains gave 1.553 mg CO2/16 days with efficacy (99.6%) and turbidity of 2.122 to 2.365 (OD 600) on various pesticides. In conclusion, the six bacterial strains could play an important role in the biodegradation process of pollutants in soils.

A group of twenty faba bean rhizobial isolates was collected from two Egyptian Governorates (Dakahlia and Damitta). The isolates were further morphologically and physiologically characterized to check their growth and symbiotic performance on faba bean plants. According to remarkable lab and pots tests, five rhizobial isolates (Rh 32, Rh 6-A, Rh 3-4, Rh RL3, and Rh 8-A) were selected and subjected to further biochemical and molecular characterizations. Genetic profiling of the five promising rhizobial isolates was conducted using six ISSR-primers. Amplification of bacterial genomic DNA produced a total of 37 genomic loci, 54% of them were polymorphic and 46% were monomorphic. The rate of polymorphism ranged between 25% to 80% with an average of 54%. Clustering pattern analysis of morphological and physiological data grouped the twenty rhizobial isolates in five clusters and the five selected rhizobial isolates were falling close to each other. Clustering analysis of ISSR data grouped the the five rhizobial isolates in four clusters. Analysis based on ISSR data revealed that the lowest genetic distance was 2.00 between Rh 6-A and Rh 3-4 isolates, while the highest genetic distance of 3.61 was between Rh 32 and each of Rh 6-A, Rh 3-4, and Rh RL3 isolates. The greatest similarity measurement was 0.931 between Rh 6-A and Rh 3-4 isolates; while the lowest similarity was 0.745 between Rh 32 and Rh 3-4 isolates. It can concluded that clustering pattern analysis based on molecular data could be used in facilitating the selection of rhizobial isolates that will be promising as a source of genes for biological nitrogen fixation and plant growth-promotion.