Influence of different Agrobacterium rhizogenes strains on hairy root induction and analysis of phenolic and flavonoid compounds in marshmallow (Althaea officinalis L.).

Hairy roots were induced in Althea officinalis using Agrobacterium rhizogenes, strains A4, A13, ATCC15834, and ATCC15834(GUS). The leaf, petiole and shoot explants of marshmallow were used for the hairy roots induction. When hairy roots appeared, cultures were established in MS (Murashige and Skoog) liquid medium without growth regulators. Hairy roots in explants appeared 5-12 days after inoculation. Maximum transformation frequency of 83% was observed on shoot explants with ATCC15834 strain. Among the strains, ATCC15834(GUS) strain showed better potential in the mass production of hairy roots in the hormone-free liquid medium after 50 days of culturing. The highest total phenolic and flavonoids content was found at 1.57 ± 0.1 mg/g dry weight in A13 strain and 3.47 ± 0.3 mg/g in A4 strain, respectively. Secondary metabolite content of hairy roots was found to be strain-specific.

Evaluation of UV/S2O8 process efficiency for removal of metronidazole (MNZ) from aqueous solutions.

Antibiotics are known today as emerging contaminants due to potentially adverse effects on aquatic ecosystems and the health of humans and animals, even at very low concentrations. The present study was conducted to evaluate the efficiency of the UV/S2O8 process and affecting factors (pH, initial metronidazole (MNZ) concentration, initial persulfate concentration and reaction time) in removing antibiotic MNZ. The results obtained from the experiments showed that the UV/S2O8 process efficiency is higher in acidic pH values due to production of further radical SO4- and increases with extended contact time, but the efficiency of the process is reduced by increasing the concentration of MNZ. In assessing the effect of initial persulfate concentration on the process efficiency, MNZ removal efficiency was also increased by 99.5% after contact time of 35 min with increasing the initial persulfate concentration up to 1 g/L. However, the process efficiency was decreased at higher concentrations (2 mg/L) due to reaction of sulfate radicals with each other or with persulfate and its saturation. The kinetic data fitted the pseudo-first-order kinetic model (R2 > 99%). The findings of this study clearly demonstrated the high potential of the UV/S2O8 process in the degradation of MNZ.