جستجوی مقالات مرتبط با کلیدواژه "آسپرژیلوس فلاوس" در نشریات گروه "پزشکی"

Aflatoxins are natural fungal toxins produced by Aspergillus species such as A. flavus. The toxins are poisoning and can cause tissue necrosis and liver cancer. The aim of this study was to determine the control of Aflatoxin B1 production by extracts and essential oils.
Aqueous extracts were prepared by heating and essential oil by Clevenger's apparatus. Antifungal activity of essential oil and aqueous extract of Mentha pulegium and Satureja hortensis were determined by disc diffusion and microplate dilution methods. Production control of Aflatoxin B1 was investigated with concentrations under MIC(Minimum inhibitory growth concentration) of two materials and were determined by HPLC method.
The most zone of inhibition was 10% belonging to Satureja essential oil and its aqueous extracts with diameters of 26mm and 12mm, respectively. These values for Mentha extract and 10% essential oil were 18mm and 8mm respectively. MIC of the aqueous extract of Satureja and Mentha were 0.031 and 0.063mg/ml respectively, and 1% essential oil of two materials was 0.039 and 0.078 mg/ml, respectively. Aflatoxin B1 produced by A. flavus in concentrations of 1%, 2% and 10% Satureja essential oil were 122, 113 and 134 ppb, in 1%, 2% and 10% Mentha were 163, 168 and 171 ppb, respectively. The aqueous extracts of 1% Satureja reduced the production of toxin as 58.1 and the 1% aqueous extract of Mentha as 39.6.
The results of this study showed that both Satureja hortensis and Mentha pulegium have the ability to inhibit the growth of Aspergillus flavus fungus, as well as control of aflatoxin B1 production in low concentrations and recommended for further studies.

Uricase (EC 1.7.3.3) is an enzyme which catalyses uric acid to H2O2 and alantoin and is utilized in the treatment of hyperuricemia or gout. The aim of this study was cloning of Aspergillus flavus uricase synthetic gene into pET-28(a) and its recombinant expression in E. coli
The coding sequence of uricase retrieved from gene bank and once optimized, the gene synthesis was ordered. Then, the synthetic gene subcloned between NcoI and XhoI within the vector. The proper subcloning was confirmed by enzymatic digestion check, PCR and finally DNA sequencing. The construct, then chemically transformed into E. coli BL21 and induced by IPTG which followed by overexpression optimization. For enzyme expression evaluation, protein gel electrophoresis was utilized.
Restriction check, PCR and sequencing indicated that the coding sequence of enzyme was cloned in the desired point of vector. The optimized condition obtained for enzyme expression was IPTG 1mM for 6 h at 22 °C. Enzyme molecular weight was determined 34.5 kDa by electrophoresis. Evaluation of uricase specific activity showed that the expressed enzyme is 7.69 U/mg and it is catalytically active.
The results of the current research showed that the uricase gene could be simply cloned and expressed in pET system. Enzyme specific activity determination exhibited that the enzyme was produced as a soluble protein and catalytically active in E. coli cytosole.