Comparison of Free and Immobilized L-asparaginase Synthesized by Gamma-Irradiated Penicillium cyclopium.

Gamma irradiation is used on Penicillium cyclopium in order to obtain mutant cells of high L-asparaginase productivity. Using gamma irradiation dose of 4 KGy, P. cyclopium cells yielded L-asparaginase with extracellular enzyme activity of 210.

Immobilization of halophilic Aspergillus awamori EM66 exochitinase on grafted k-carrageenan-alginate beads.

A novel extreme halophilic exochitinase enzyme was produced by honey isolate Aspergillus awamori EM66. The enzyme was immobilized successfully on k-carrageenan-alginate gel carrier (CA) with 93 % immobilization yield. The immobilization process significantly improved the enzyme specific activity 2.

Detection of gyrA mutation among clinical isolates of Campylobacter jejuni isolated in Egypt by MAMA-PCR.

Introduction: Campylobacter spp are the major cause of enteritis in humans and more than 90% of reported infections are caused by Campylobacter jejuni. Fluoroquinolones such as ciprofloxacin are the antibiotics of choice for treatment. An increase in the frequency of ciprofloxacin-resistant Campylobacter has been reported globally due to a single base mutation (C-257 to T) in codon 86 of the quinolone resistance determining region (QRDR) of the gyrA gene altering the amino acid sequence from threonine at position 86 to isoleucine (Thr-86 to Ile).

Characterization of an exopolygalacturonase from Aspergillus niger.

Polygalacturonase (PGI) from Aspergillus niger NRRL3 was purified about 12.0-fold from the cell-free broth using diethylaminoethyl-Sepharose and Sephacryl S-200 columns. The molecular weight of the PGI was 32,000 Da as estimated by gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

Purification and characterization of a glutathione S-transferase from Mucor mucedo.

An intracellular glutathione transferase was purified to homogenity from the fungus, Mucor mucedo, using DEAE-cellulose ion-exchange and glutathione affinity chromatography. Gel filtration chromatography and SDS-PAGE revealed that the purified GST is a homodimer with approximate native and subunit molecular mass of 53 kDa and 23.4 kDa, respectively.