Publications by authors named "M Boumaiza"

28 Publications

Biochemical, Biophysical and Functional Characterization of an Insoluble Iron Containing Hepcidin-Ferritin Chimeric Monomer Assembled Together with Human Ferritin H/L Chains at Different Molar Ratios.

Curr Issues Mol Biol 2021 Dec 28;44(1):117-127. Epub 2021 Dec 28.

Laboratoire d'Ingénierie des Protéines et des Molécules Bioactives, Institut Nationale des Sciences Appliquées et de Technologie BP 676, Tunis 1080, Tunisia.

Hepcidin and ferritin are key proteins of iron homeostasis in mammals. In this study, we characterize a chimera by fusing camel hepcidin to a human ferritin H-chain to verify if it retained the properties of the two proteins. The construct (HepcH) is expressed in in an insoluble and iron-containing form. To characterize it, the product was incubated with ascorbic acid and TCEP to reduce and solubilize the iron, which was quantified with ferrozine. HepcH bound approximately five times more iron than the wild type human ferritin, due to the presence of the hepcidin moiety. To obtain a soluble and stable product, the chimera was denatured and renatured together with different amounts of L-ferritin of the H-chain in order to produce 24-shell heteropolymers with different subunit proportions. They were analyzed by denaturing and non-denaturing PAGE and by mass spectroscopy. At the 1:5 ratio of HepcH to H- or L-ferritin, a stable and soluble molecule was obtained. Its biological activity was verified by its ability to both bind specifically cell lines that express ferroportin and to promote ferroportin degradation. This chimeric molecule showed the ability to bind both mouse J774 macrophage cells, as well as human HepG2 cells, via the hepcidin-ferroportin axis. We conclude that the chimera retains the properties of both hepcidin and ferritin and might be exploited for drug delivery.
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http://dx.doi.org/10.3390/cimb44010009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8929011PMC
December 2021

Spatio-temporal distribution patterns of Chironomidae communities in the wadis of Northern Tunisia.

Braz J Biol 2021 10;82:e247073. Epub 2021 May 10.

Laboratory of Biomonitoring of the Environment LR01 ES14, University of Carthage, Faculty of Sciences of Bizerte, Zarzouna 7021, Tunisia.

In Northern Tunisia, seasonal streams, called wadi, are characterized by extreme hydrological and thermal conditions. These freshwater systems have very particular features as a result of their strong irregularity of flow due to limited precipitation runoff regime, leading to strong seasonal hydrologic fluctuations. The current study focused on the spatio-temporal distribution of chironomids in 28 sampling sites spread across the Northern Tunisia. By emplying PERMANOVA, the results indicated a significant spatio-temporal variation along various environmental gradients. The main abiotic factors responsible for noted differences in the spatial distribution of chironomids in wadi were the conductivity and temperature, closely followed by altitude, pH, salinity, talweg slope and dissolved oxygen, identified as such by employing distance-based linear models' procedure. The Distance-based redundancy analysis ordination showed two main groups: the first clustered the Bizerte sites, which were characterized by high water conductivity, sodium concentration and salinity. The second main group comprised sites from the Tell zone and was characterized by low temperatures, neutral pH, low conductivity and nutrients content. The subfamily TANYPODIINAE (e.g., Prochladius sp., Prochladius choerus (Meigen, 1804) and Macropelopia sp.) was the dominant group at Tell zone, whereas species such as Diamesa starmachi (Kownacki et Kownacha, 1970) and Potthastia gaedii (Meigen, 1838) were found only in Tell Wadis. In contrast, chironomid species such as Diamesa starmachi (Kownacki et Kownacha, 1970), Potthastia gaedii (Meigen, 1838), Procladius choreus (Meigen, 1804) were specific for Tell Mountain. Cap Bon wadis region was dominated by genus Cladotanytarsus sp. The results of this survey liked the taxonomic composition of chironomid assemblages to the variation of hydromorphological and physic-chemical gradients across the northern Tunisia wadis.
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http://dx.doi.org/10.1590/1519-6984.247073DOI Listing
May 2021

Production and characterization of a fusion form of hepatitis E virus ORF2 capsid protein in .

Prep Biochem Biotechnol 2021 23;51(6):562-569. Epub 2020 Oct 23.

Laboratory of Molecular Microbiology, Vaccinology and Biotechnology Development, Group of Biotechnology Development, Institut Pasteur de Tunis, Université Tunis El Manar, Tunis, Tunisia.

Hepatitis E virus (HEV) is a nonenveloped virus causing an emerging zoonotic disease posing a severe threat to the public health in the world, especially to pregnant women. In this study, a truncated form (aa 368-606) of the open reading frame 2 of the capsid protein (ORF2-HEV), a major structural protein of HEV, was expressed in . This work characterizes for the first time, the fused Glutathione-S-Transferase-tagged ORF2 (GST-ORF2) and ORF2-HEV forms in . The fusion protein was purified by affinity chromatography with a purity higher than 90% and to yield about 27% after thrombin digestion. The purified GST-ORF2 protein was then characterized by western blot, using anti-GST antibodies, and CD spectroscopy. The GST-ORF2 and ORF2-HEV proteins were shown to be efficient to develop an ELISA test to detect anti-HEV IgG in mice sera immunized with a recombinant full length ORF2 protein. Sera showed a significant increase of the absorbance signal at 450 nm, in plate wells coated with a quantity of 0.5, 1 and 2 µg of proteins. ELISA plates coated with the purified GST-ORF2 and ORF2-HEV showed similar response when compared to the HEV ELISA where total insect cell lysate, infected with the recombinant baculovirus expressing full ORF2, was used as positive control.
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http://dx.doi.org/10.1080/10826068.2020.1836656DOI Listing
July 2021

Application of isolated and strains as a probiotic starter culture during the industrial manufacture of Tunisian dry-fermented sausages.

Food Sci Nutr 2020 Aug 3;8(8):4172-4184. Epub 2020 Jul 3.

Faculté des Sciences de Tunis LR03ES03 Microorganismes et Biomolécules Actives Université de Tunis El Manar Tunis Tunisia.

For decades, lactic acid bacteria has been isolated and selected to be used as starter cultures in meat fermentation for standardization and management of quality of dry-fermented sausage which constitute a considerable challenge. The aim of this study was to evaluate the effect of strains, isolated from different origins, on qualities of dry-fermented sausages. These last, manufactured with different combinations of starter cultures ( + ), were ripened, using the same raw materials and conditions, for 45 days. Samples were collected during this period, and microbiological, physicochemical, fatty acid profile, and sensorial analyses determined. Lactic acid bacteria were the dominant flora during ripening. A desirable PUFA/SFA ratio, corresponding to 1:1.7 (0.6), was detected after 24 days of maturation in sausages inoculated by BMG 95 and . Sensory analysis showed that fermented sausages manufactured with and had a more desirable odor, flavor, and texture and consequently were preferred overall. In particular, sensory panellists preferred sausages produced with either 23K or BMG 95 when compared to fermented sausage produced with a commercial starter or no starter at all.
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http://dx.doi.org/10.1002/fsn3.1711DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7455971PMC
August 2020

Microbiological quality and safety of commercialized thalassotherapy products based on marine mud and algae extracts in Tunisia.

Arch Microbiol 2020 Nov 30;202(9):2437-2451. Epub 2020 Jun 30.

Laboratory of Microorganisms and Active Biomolecules, MBA-LR03ES03, Faculty of Sciences of Tunis, University of Tunis El Manar, Tunis, Tunisia.

A total of 15 samples of thalassotherapy products, distributed in Tunisia in their intact and final state of production, was analyzed to determine their microbiological safety status. The result shows the absence of pathogenic bacteria (Staphylococcus aureus, Candida albicans, Salmonella, Pseudomonas aeruginosa and coliforms). The incidence of contamination by Gram-positive Bacilli (mesophelic bacteria, aerobic and anaerobic spore forming bacteria, anaerobic sulphite-reducing bacteria) was found to be higher in products composed by mud and extract of alga. The biochemical and molecular identification of the major contaminant show that Bacilli were the most covered from 75% of the thalassotherapy products. Mineral analysis (organic matter, Fe, Mg, Ca, Na d K, Al, Si and Ti) shows strong composition on Aluminum and Silica. Cytotoxicity study of six thalassotherapy products and three essential oil extracts (Menthol, Clove and Eucalyptus) did not show any cytotoxic effect. Furthermore, antibacterial acitivity of 5 essentila oils, against 30 isolates of the genus Bacillus and 10 reference strains, has been characterized showing an interesting bactericidal potential of the extract of menthol and Eucalyptus.
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http://dx.doi.org/10.1007/s00203-020-01957-1DOI Listing
November 2020
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