Two different substrates, sunflower (Helianthus annuus L.) tubers and lettuce (Lactuca sativa) roots, were tested. Using a mixture of both wastes resulted in higher production of endoinulinase than either waste alone. Also, ten fungal species grown on these substrates as inexpensive, carbon sources were screened for the best production of endoinulinase activities. Of these, Aspergillus niger AUMC 9375 was the most productive, when grown on the mixture using a 6:1 w/w ratio of sun flower: lettuce, and yielded the highest levels of inulinase at 50% moisture, 30°C, pH 5.0, with seven days of incubation, and with yeast extract as the best nitrogen source. Inulinase was purified to homogeneity by ion-exchange chromatography and gel-filtration giving a 51.11 fold purification. The mixture of sunflower tubers and lettuce roots has potential to be an effective and economical substrate for inulinase production. Inulinase was successfully immobilized with an immobilization yield of 71.28%. After incubation for 2 h at 60°C, the free enzyme activity decreased markedly to 10%, whereas that of the immobilized form decreased only to 87%. A reusability test demonstrated the durability of the immobilized inulinase for 10 cycles and in addition, that it could be stored for 32 days at 4°C. These results indicate that this inulinase, in the immobilized form, is a potential candidate for large-scale production of high purity fructose syrups.

No abstract

A N ECO-FRIENDLY protocol for the biosynthesis of extracellular zinc nanoparticles (ZnNPs) by Penicillium chrysogenum was performed. The formation of ZnNPs was observed by the formation of white aggregates of ZnNPs and confirmed by UV absorption spectrum at 340nm. The synthesized ZnNPs were also characterized by High resolutiontransmission electron microscope (HR-TEM), dynamic light scattering (DLS) and fourier transform infrared spectroscopy (FT-IR). The optimum conditions were pH 10, 72h of reaction between culture filtrate (CF) and 1mM (ZnSO 4) solution with (6:1) ratio. Exposure of ZnNPs to gamma radiation showed an increase in the absorption band intensities when compared to the non irradiated sample. Samples of ZnNPs exposed to 20kGy dose recorded the greatest antimicrobial effect. The study of its antitumor activity against human breast carcinoma (MCF-7) and colon carcinoma cells (HCT-116) was performed. The IC 50 values of (MCF-7) were 373µg/ml and >500µg/ml, while of (HCT-116) were 226 and 317µg/ml for irradiated and non irradiated samples, respectively. TEM and DLS showed the formation of spherical monodispersed ZnNPs from 9 to 17nm with a mean of 13nm for the irradiated sample exposed to 20kGy. The current research provided an insight on using ɤ-radiation as a highly efficient and inexpensive tool for the enhancement of antimicrobial and antitumor effects of nanoparticles against infectious and tumor diseases.

No abstract

No abstract