Mycosynthesis of silver nanoparticles by an endophytic Penicillium species of Aloe vera root, evaluation of their antibacterial and antibiotic enhancing activity

In the recent past green synthesis has emerged as an important and eco friendly technology in the field of nanosciences for the synthesis of various metal nanoparticles of variable sizes and shapes. The present study focuses on the mycosynthesis (i.e., synthesis by fungi) of silver nanoparticles by an important species of Penicillium, an endophytic fungus isolated from the roots of Aloe vera plant. The silver nanoparticle synthesizing efficiency of the fungus was evaluated visually on the basis of change of colour of the reaction mixture and by UV/Visible spectroscopy. These silver nanoparticles were characterized by transmission electron microscopy (TEM) and fourier transform infrared spectroscopy (FTIR) for the analysis of size, shape, dispersity and presence of different functional groups respectively. The formation of silver nanoparticles were initially observed by change in colour of the reaction mixture and was confirmed by UV/VIS spectroscopy that showed an absorption peak between 380-680 nm which is the characteristic wavelength range of silver nanoparticles. The silver nanoparticles were screened out for the presence of antibacterial activity against standard bacterial pathogens (Escherichia coli, MRSA, Pseudomonas aeruginosa and Staphylococcus aureus) and their role as antibiotic enhancer was also determined using some important broad range commercial antibiotics (Penicillin, Methicillin, Ampicillin and Amoxicillin). The results of these studies revealed a significant antibacterial activities of silver nanoparticles against the used bacterial test pathogens and were also capable of enhancing efficiently the antibacterial activities of different commercial antibiotics when used in combination. © 2014 Universal Research Publications. All rights reserved