Microencapsulation of Bacillus velezensis Using Alginate-Gum Polymers Enriched with TiO2 and SiO2 Nanoparticles.

Bacillus bacteria are a group of plant growth stimulants that increase plant growth and resistance to plant pathogens by producing various metabolites. With their large surface area and small size, nanoparticles can be used in controlled-release formulations and increase the efficiency of the desired product. Encapsulation of biological agents in combination with nanoparticles can be an essential step in increasing the performance of these agents in adverse environmental conditions. In this study, which is the result of a collaboration between scientists from Italy and Iran, Bacillus velezensis was encapsulated in alginate combined with whey protein and zedo, mastic, and tragacanth gums in the presence of silica and titania nanoparticles to obtain two-layer and multilayer assemblies acting as novel, smart micro-encapsulation systems. The results of laboratory studies showed that the B. velezensis could produce protease, lipase, siderophore, auxin, and a dissolution of mineral phosphate. Scanning electron microscopy images (SEM) showed that the studied microcapsules were almost spherical. Moisture affinity, swelling, and efficiency of each microcapsule were examined. The results showed that the highest encapsulation efficiency (94.3%) was related to the multilayer formulation of alginate-whey protein-zedo. XRD and FTIR spectroscopy showed that the alginate, whey protein, and zedo were mixed properly and no incompatible composition occurred in the reaction. This study aimed to provide a suitable formulation of biofertilizers based on biodegradable compounds as an alternative to chemical fertilizers, which is low cost and very effective without harming humans and the environment.

Incorporation of Fluorinated Pyridine in the Side Chain of 4-Aminoquinolines: Synthesis, Characterization and Antibacterial Activity.

A series of hybrid of 4-aminoquinoline and fluorinated pyridine derivatives were synthesized and their chemical structure were confirmed by 19F-NMR, 1H-NMR, 13C-NMR and FT-IR. All compounds were tested against one Gram-positive and one Gram-negative bacteria to assess their in vitro antibacterial activity. Compounds 10A: , 10B: , 11A: and 12B: showed moderate antibacterial activity against Gram-positive bacterium, Staphylococcus aureus.

Ultrasound promoted facile synthesis of some pentafluoropyridine derivatives at ambient conditions.

Some pentafluoropyridine derivatives have been synthesized by the reaction of pentafluoropyridine with appropriate mono and bidentate nucleophile under ultrasonic irradiation. This new methodology provides good to excellent yields in short reaction times (25-120 min) at room temperature.

Acceleration of alkenyltrimethylsilane fluorination under mild conditions using ultrasound.

Alkenyltrimethylsilanes are selectively fluorodesilated to alkenyl fluoride very readily by reaction with 1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2,2,2]octane bis-tetrafluoroborate (Selectfluor) and N-fluorobenzensulfonimids at room temperature under ultrasound. In the presence of ultrasound irradiation in the case of one of the reactions, the yield was 85% after 25 min, but using the previously established thermal method the yield was only 32% after 20 h.