Haytham M.M. Ibrahim

• Professor
• Head of Radiation Microbiology Department (NCRRT) at Egyptian Atomic Energy Authority

The PCR amplification of 16S rRNA gene and surfactin gene from the 14 B. subtilis isolates capable of producing a lipopeptide biosurfactant (surfactin) was performed. Only two isolates producing a high yield of surfactin were selected and subjected to molecular characterization, identification and optimization of their surfactin production. These t...

Antimicrobial nanocomposite films containing oregano essential oil (EO) were prepared by solvent casting. Film matrix was composed of supramolecular poly(lactic acid)–cellulose nanocrystals (PLA–CNC) nanocomposite. Bioactive PLA–CNC–oregano films were prepared by incorporating oregano EO as an antimicrobial agent. Resulting films were then converte...

The present study reports an eco-friendly, cost efficient, rapid and easy method for synthesis of silver nanoparticles using banana peel extract (BPE) as a reducing and capping agent. The different factor affecting silver reduction was investigated. The optimum conditions were silver nitrate (1.75 mM), BPE (20.4 mg dry weight), pH (4.5) and incubat...

Titanium dioxide (TiO2) is a well-studied photocatalyst that is known to break down organic molecules upon ultraviolet irradiation. TiO2 thin films were fabricated on glass substrates using the doctor-blade procedure, the film surface was modified with silver nanoparticles to increase its visible light response. The Ag-TiO2 films were characterized...

This study focused on characterization of chitosan obtained in a previous study from fermented shrimp shell waste (SSW) by Bacillus subtilis NA12. Extracted chitin was exposed to different gamma radiation doses (5-35 kGy). The molecular weight of the resultant chitosan decreased constantly with increasing radiation dose from 1.9 × 106 (g/mol) (non-...

Used engine oil (UEO) constitutes a serious environmental problem due to the difficulty of disposal off or reuse. Ten bacterial strains with biodegradation potential were isolated from UEO-contaminated soil sample using enrichment technique. Two strains which exhibited the highest degradation %, 51 ± 1.2 and 48 ± 1.5, respectively, were selected. B...

Microbial surfactants are widely used for industrial, agricultural, food, cosmetics, pharmaceutical, and medical applications. In this study, two bacterial strains namely, Ochrobactrum anthropi HM-1 and Citrobacter freundii HM-2, previously isolated from used engine oil contaminated soil, and capable of producing biosurfactants, were used. Their ce...

Effect of 2-hydroxylethyl methacrylate (HEMA) monomer grafted on methylcellulose (MC)-based films was characterized. Films were obtained by casting and then exposed to gamma irradiation (5-25 kGy). Results revealed that 1% HEMA-containing films showed the highest puncture strength values (282 N/mm) at 10 kGy. FTIR analysis showed a decrease of the...

Polypropylene fibers were treated against microbial effects by gamma radiation-induced grafting of acrylic acid, followed by metal complexation with Zn2+ or Ag+ metal ions. The treated polypropylene fibers were characterized by using Fourier transform infrared spectroscopy and scanning electron microscopy. The effect of the treatment on the thermal...

New bioactive nanocomposite films were prepared by compression molding method for food applications. Film matrix was composed of poly(lactic acid) containing cellulose nanocrystals (PLA-CNC). Nanocomposite films were converted to bioactive films using nisin as an antimicrobial agent by an adsorption coating method. Resulting antimicrobial films wer...

Abstract This research has demonstrated that cellulose derivatives and alginate are promising polymers for the development of natural edible coatings. The use of irradiation to crosslink these polymers have beneficial effects to improve the shelf life and to preserve the overall quality of ready to eat coated vegetables and fruits i.e. coated pre-c...

Anionic surfactants, e.g., sodium dodecyl sulfate (SDS), as a main components in the detergent and cosmetic industries, contribute significantly to the pollution profile of sewage and wastewaters of all kinds. The purpose of this study was to isolate local SDS degrading bacteria. Screening was carried out by the conventional enrichment culture tech...

An eco-friendly process for the synthesis of silver nanoparticles has been attempted, using the culture filtrate of various microorganisms, included bacteria, fungi and yeast. Only fungi, especially Aspergillus niger, were capable of synthesizing silver nanoparticles. The culture filtrate treated with AgNO3 (1 mM) turned dark brown after 72 h of in...

Fourteen bacterial isolates belonging to B.subtilis were locally isolated from soil and screened for alkaline protease production. Only one strain, the highly potent one, was selected as alkaline protease producer and subjected to further studies to optimize its production. Alkaline protease production was maximum at 35 degree C after 72 h of incub...

Bacillus subtilis strains previously isolated from soil, with the ability to produce extracellular α-amylase, were screened for the most potent one. B. subtilis strains number 210 and 262 were selected; they produced 1930 and 3445 U/ml of α-amylase, respectively, in medium containing soluble starch. Also, they were able to produce α-amylase utilizi...

Twelve filamentous fungal strains, belonging to the genus Aspergillus, Penicillium, Fusarium, Alternaria and Trichoderam, were screened for poly lactic acid (PLA) biodegradation in solid and liquid media. The selected three fungal strains, namely Aspergillus oryzae, Penicillium chrysozenum and Fusarium oxyporium, were able to assimilate the polymer...

The antibacterial activity of irradiated and non-irradiated chitosan against E.coli, S.aureus, Salmonella, Strep. fecalis,Closteridium and P. aerugenosa was studied. Up to 1.25 mg/l, chitosan hardly suppressed the growth of all the strains while 3 mg/l of chitosan clearly inhibited the growth of all the studied strains. Therefore, the concentration...

Three hundred and sixty-eight bacterial isolates; isolated from Egyptian cultivated soil, were screened for biosurfactant producers utilizing the drop collapsing assay, only 14 isolates were capable of producing biosurfactants, these isolates were identified as B. subtilis. The activity of the produced biosurfactant was examined by measuring the su...