The study of antifungal activities of magnesium oxide and copper oxide nanoparticles against different species of Aspergillus

Background & Objective: Food can be contaminated with various fungi. The use of nanotechnology, especially metal oxides can reduce this contamination. The aim of this study was to investigate the antifungal effect of magnesium oxide and copper oxide nanoparticles against Aspergillus species that are important in food hygiene. Materials & Methods: Magnesium oxide and copper oxide nanoparticles were synthesized chemically, then their morphology and size were investigated by transmission electron microscopy, scanning electron microscopy, X-ray diffraction and zetasizer. MIC and MFC of these nanoparticles against Aspergillus species were examined individually and in combination with each other by micro dilution method in saboraud dextrose broth and saboraud dextrose agar media and FIC was calculated. Results: The size of nanoparticles was between 10 to 60 nm. They had different forms and high purity. The mean MIC and MFC values of magnesium oxide nanoparticles for the species of A. flavus, A. fumigatus, A. niger and A. parasiticus were 10.1 and 10.31 mg/ml, respectively. These values for copper oxide nanoparticles were 10.25 and 10.08, respectively. Most inhibitory and fungicidal effect of these nanoparticles was on A. niger and A. fumigatus respectively. Since FIC index was greater than 1, there was no interaction. The mean MIC value of the two nanoparticles combination was 9.49 mg/ml. Conclusions: This study showed that each of magnesium oxide or copper oxide nanoparticles as anti-fungal substances could have inhibitory and fungicidal properties individually, but their combination do not have any interacting effect

Usporedba biokemijskih i funkcionalnih svojstava devina i goveđega mesa tijekom smrzavanja.

The quality of camel meat has received little attention. It is nutritionally as good as that of the major sources of red or white meats. The purpose of this study was to compare the biochemical and functional properties of fresh and frozen camel meat with cattle meat. Twenty four slaughtered animals (camel and cattle) of different ages and sexes were randomly sampled. Samples from biceps femoris, triceps brachii, longissimus dorsi, and heart muscles were removed and external fat and epimysial connective tissues separated. Measurement of gross composition, pH, water holding capacity (WHC), total volatile nitrogen (TVN), peroxide value, acid value, tensile strength analysis and myofi brillar protein electrophoresis was done on meat samples. Meat samples were frozen for 1, 4 and 8 weeks at -18 °C. After defrosting, WHC, dripping loss, TVN, peroxide value, acid value and kreis test were determined at each storage time. Results indicated that for most of the factors studied, fresh camel and cattle meat were similar, except for ash and fat contents which were lower in camel meat (P<0.05). In the frozen state, camel and cattle meat were similar in all parameters except TVN, acid value, WHC and dripping loss. The latter was higher and others were lower in camel meat (P<0.05). In conclusion, the quality of camel meat is comparable with cattle meat. It may even have an edge over beef or lamb due to its low intramuscular fat and cholesterol contents. However, since animals are usually slaughtered at the end of their productive life, camel meat is usually tough. In view of the above it is possible that camel meat could make a greater contribution to the growing need for meat in developing countries.Malo pozornosti pridaje se kakvoći devina mesa. Hranidbeno je jednako vrijedno kao i ostale vrste crvena mesa. Stoga je cilj ovog istraživanja usporediti biokemijska i funkcionalna svojstva svježega i smrznutoga devina mesa sa svojstvima goveđega mesa. Nasumce su bili uzeti uzorci m. biceps femoris, m. triceps brachii, m. longissimus dorsi i srčanoga mišića od 24 životinje (deva i goveda) različite dobi i spola. Od svakog uzorka odstranjeno je vanjsko masno tkivo i epimizijalno vezivno tkivo. Svakom uzorku elektroforezom je bio određen sastav, pH, sposobnost vezanja vode, ukupni hlapljivi dušik, peroksidni broj, stupanj kiselosti, žilavost i proteinski sastav miofi brila. Uzorci su bili zamrznuti tijekom jedan, četiri i osam tjedana pri temperaturi -18 oC. Nakon odmrzavanja određivana je sposobnost vezanja vode, gubitak vode, ukupni hlapljivi dušik, peroksidni broj, stupanj kiselosti i vrijednosti dobivene Kreisovim testom. Svježe devino i goveđe meso bilo je slično po većini pretraživanih pokazatelja, osim po sadržaju pepela i masti za koje su ustanovljene značajno manje vrijednosti u devinu mesu (P<0,05). Smrznuto devino i goveđe meso bilo je slično po svim pretraživanim pokazateljima osim po sadržaju ukupna hlapljiva dušika, stupnju kiselosti, sposobnosti vezanja vode i gubitka vode. Gubitak vode bio je veći, a vrijednosti ostalih pokazatelja bile su manje za devino meso (P<0,05). Može se zaključiti da je kakvoća devina mesa usporediva s kakvoćom goveđega mesa, čak i bolja s obzirom na to da sadrži malo mišićne masti i kolesterola. Ipak, budući da se deve kolju pod kraj života, devino meso obično je žilavo. S obzirom na sve rečeno devino meso trebalo bi više upotrebljavati u rastućim potrebama za mesom u zemljama u razvoju

In Silico Analysis of Glutaminase from Different Species of Escherichia and Bacillus

Background: Glutaminase (EC 3.5.1.2) catalyzes the hydrolytic degradation of L-glutamine to L-glutamic acid and has been introduced for cancer therapy in recent years. The present study was an in silico analysis of glutaminase to further elucidate its structure and physicochemical properties. Methods: Forty glutaminase protein sequences from different species of Escherichia and Bacillus obtained from the UniProt Protein Database were characterized for homology search, physiochemical properties, phylogenetic tree construction, motif, superfamily search, and multiple sequence alignment. Results: The sequence level homology was obtained among different groups of glutaminase enzymes, which belonged to superfamily serine-dependent β-lactamases and penicillin-binding proteins. The phylogenetic tree constructed indicated 2 main clusters for the glutaminases. The distribution of common β-lactamase motifs was also observed; however, various non-common motifs were also observed. Conclusion: Our results showed that the existence of a conserved motif with a signature amino-acid sequence of β-lactamases could be considered for the genetic engineering of glutaminases in view of their potential application in cancer therapy. Nonetheless, further research is needed to improve the stability of glutaminases and decrease their immunogenicity in both medical and food industrial applications