The present study investigated the biosynthesis of silver (AgNPs), zinc oxide (ZnONPs) and titanium dioxide (TiO2NPs) nanoparticles using Aspergillusoryzae, Aspergillusterreus and Fusariumoxysporum. Nanocomposites (NCs) were successfully synthesized by mixing nanoparticles using a Sonic Vibra-Cell VC/VCX processor. A number of analytical techniques were used to characterize the synthesized biological metal nanoparticles. Several experiments tested biologically synthesized metal nanoparticles and nanocomposites against two types of human pathogenic bacteria, including Gram-positive Staphylococcus aureusand methicillin-resistant Staphylococcus aureus (MRSA), and Gram-negative Escherichia coli and Pseudomonasaeruginosa. Additionally, the antitumor activity in HCT-116 cells (colonic carcinoma) was also evaluated. Significant antimicrobial effects of various synthesized forms of nanoparticles and nanocomposites against E. coli and P. aeruginosa bacteria were detected. Various synthesized biogenic forms of nanoparticles and nanocomposite (9.0 to 29 mm in diameter) had high antibacterial activity and high antitumor activity against HCT-116 cells (colonic carcinoma) with IC50 values of 0.7–100 µg/mL. Biosynthesized NPs are considered an alternative to large-scale biosynthesized metallic nanoparticles and nanocomposites, are simple and cost effective, and provide stable nanomaterials.

A field experiment was conducted in a newly reclaimed soil at El-Saff region, El-Giza Governorate, Egypt to study the effects of different rates of nitrogen (N: 62 to 248 kg ha −1 ) with or without soil inoculation of sulfur-(S-) oxidizing bacteria (SoxB) and combined inoculation of SoxB and N-fixing bacteria (NFxB) on yield, quality and nutritional status of onion (Allium cepa L., "Giza 20"). Elemental S at 620 kg ha −1 was applied to all treatments. Application of N at 62, 124, and 248 kg ha −1 rates increased onion yield, plant height, and N uptake by 28 to 76%, 32 to 53%, and 61 to 145%, as compared to those of the plants that received no N. Inoculation of SoxB at various N rates increased onion yields by 47 to 69% and N uptake by 76 to 93%, as compared to those of the plants which received the respective rates of N but no SoxB inoculation. Inoculation with SoxB and NFxB increased onion yield by 221%, plant height by 62%, and N uptake by 629%, as compared to those of the plants grown without inoculation and no N applied.

Due to the wide and inappropriate use of the antibiotics, the development of new resistant strains of bacteria to the most of common antibiotics has become a serious problem in public health; so there is a strong stimulant to continuity developing new and effective antimicrobial agents. Nanotechnology considers as a magic tool to explore and treat the difficult problems of medical sciences. The confluence of nanotechnology and microbiology solves several biomedical problems, and also can revolutionize the health and medicine fields. Recently reports prove that carbon-based nanomaterials like multiwalled carbon nanotubes (MWCNTs) show potent antimicrobial properties. The nanocomposite chitosan-multiwalled carbon nanotube (Ch/MWCNT) was synthesized by the process of sonication for 20 min and examined their antibacterial activity. Seven different concentrations of MWCNT were used in the preparation of Ch/MWCNT (from 5 to 100 mg). The prepared differently concentrated MWCNT nanocomposite was characterized using TEM and FTIR. According to TEM results which showed that the morphology of MWCNTs were obtained in the form of small tubes of a length. FTIR show that the presence of the C=C absorption at the wave number 2344 cm-1 which confirm the successful incorporation between chitosan and MWCNT. For antimicrobial activity estimation, the serial dilution method was used towards Gram positive bacteria (Staphylococcus aureus NRC 23516, Methicillin-resistant Staphylococcus aureus (MRSA) NRC 629012) and Gram negative bacteria (Escherichia coli 0157H7 and Pseudomonas aeruginosa ATCC10145). The composite Ch/MWCNT showed higher antimicrobial activity against both Gram negative and Gram positive bacteria; P. aeruginosa, Staphylococcus aureus; respectively with increasing MWCNT concentrationtill ratio 1:4. The nanocomposites are highly differentiable at the low concentration; 1% concentration of the multifunctional nanocomposite is very effective against the tested microbes. Minimal inhibitory concentrations (MIC) of Ch/MWCNT (100:50 Ch/MWCNT) against Gram negative and Gram positive pathogenic bacteria between 0.5 and 0.0625 μg, and the growth inhibition effect was observed in a concentration-dependent species.

A newly cultivated sandy soil was supplemented with composted (rice straw, maize stalks, water hyacinth) or farmyard manure (FYM) in the presence and absence of multi-biofertilizers to evaluate its effect on growth, yield and yield components of peanut plants grown in pot experiment. Counts of phosphate dissolving bacteria, Azospirillum spp. and Pseudomonas spp. were always higher in the rhizosphere of plants growing in soil treated with various composted plant residues in the presence and absence of biofertilizers as compared to FYM or chemical fertilizer application. The amendment of soil with composted rice straw recorded higher counts of tested microorganisms in peanut rhizosphere as compared to composted water hyacinth or maize stalks under biofertilizers application. The dry weight of different peanut organs and the fresh weight of nodules were increased as a result of organic wastes fertilization alone or in combined with biofertilizers as compared to chemical fertilizer treatment. Significant differences in peanut yield of pods and seeds were obtained between composted rice straw or water hyacinth along with biofertilizers and NPK treatment (control). Generally, the addition of biofertilizers with different organic wastes led to improve the quantity and quality yield of peanut plants as compared to various organic wastes alone or chemical fertilizer application. Concentration of P, Zn, Mn, Fe and Cu in peanut seeds exhibited marked increases over chemical fertilization as a result of biofertlization under different organic wastes application. Peanut seeds contained the greatest percentage of protein and oil when plants were fertilized with composted water hyacinth or rice straw in the presence of biofertilizers.