ABSTRACT
Objective: Organophosphorus [OPs] compounds are widely used in many pesticides, insecticides and chemical nerve agents. These compounds are hazardous for humans and the environment. Organophosphate hydrolase [OPH] is a homodimeric protein initially isolated from Pseudomonas diminuta MG and Flavobacterium species. This enzyme is able to degrade a broad spectrum of toxic OPs compounds. Using immobilized OPH commonly presents a variety of advantages versus the free form of the enzyme. Advantages include an increase in stability, cost reduction by simple recovery and reutilization of the enzyme, quick and easy separation of the reactant and product in the reaction medium
Methods: Plasmid pET-26b [+] was used to generate the OPH protein under the control of the T7lac promoter. E. coli BL21 [DE3] pLysS was used as the host for expression of the OPH enzyme. Recombinant OPH was secreted into the extracellular medium and the purified enzyme was immobilized on the surface of Bacillus subtilis spores by the adsorption method, for the first time
Results: Approximately 42% to 45% enzymatic activity was determined to be associated with spores. Optimal pH and temperature of the enzyme were not altered by the presence of the spores. Thermo and pH stabilities of the immobilized enzyme was higher than the free form of the enzyme. Conclusion: Bacillus subtilis spores are safe for humans and the environment. Therefore this system can be considered an environmentally friendly biocatalyst for degradation of OPs
Conclusion: Bacillus subtilis spores are safe for humans and the environment. Therefore this system can be considered an environmentally friendly biocatalyst for degradation of OPs.
ABSTRACT
Owning to therapeutic properties, flixweed and marsh mallow have traditionally been very important in Iran. In this research study the effect of various concentrations of ethanol flixweed seed and marsh mallow root extracts, collected from different areas of Iran, was studied on Streptococcus pyogenes; the effect of the extract with antibiotics of penicillin, erythromycin and amoxicillin was compared in a completely randomized design with four replications. In this experimental study, discs impregnated with concentrations of 25, 50, 100, 250 mg/mL were prepared from ethanol extract of flixweed concentration in Jiroft, Baghin, Rafsanjan and Kohbanan as well as marsh mallow root extract in Tehran, Isfahan, Yazd and Kerman. Then, they were placed on culture medium of blood agar that S. pyogenes has grown on. Finally, inhibitory effect was evaluated. The results showed that, among different areas and available antibiotics, the highest inhibition zone was related to marsh mallow root extract of Yazd in concentration of 250 mg/mL with 14.5 mm. Beta hemolysis was observed on concentrations of 50, 100 and 250 mg/mL of flixweed seed extracts in all areas; thus, these concentrations are not suitable for producing herbal medicine. Concentration of 25 mg/mL, however, showed no hemolysis in all areas. The best extract to produce herbal medicines with flixweed seed was related to concentrations of 25 mg/mL. Penicillin had the highest inhibition zone with 8.31 mm. Considering the significant difference in the level of 0.01%, marsh mallow root extracts have more anti-bacterial effect than flixweed seed extracts
ABSTRACT
Based on the purpose of conservation planning for native species, sixteen populations of cattle, goat and sheep were analyzed by amplification of genomic DNA using inter-simple sequence repeat [ISSR] markers to estimate of genetic structure. DNA samples of 275 animals were collected to Paccess their genetic content. The polymorphism information content [PIC] values and genetic diversity in sheep populations were higher than the others. The mean coefficient of gene differentiation [Gst] was 0.3615, indicating that 19.42% of the genetic diversity resided within the population. In total, 60 fragments in PCR products were indicated by using ISSR primers and generally most of the fragments were common in all populations, but differed in their frequency. A cluster analysis was carried out using unweighed pair group method with arithmetic averages [UPGMA] and dendrogram illustrated genetic relationships among 275 individuals in three species. Haplotypes were constructed computationally and frequencies were compared in each species. The results of this study can provide basic molecular information for future research on native livestock using ISSR markers