Biogenic Synthesis of Silver Nanoparticles Mediated by the Consortium Comprising the Marine Fungal Filtrates of Penicillium Oxalicum and Fusarium Hainanense Along With Their Antimicrobial, Antioxidant and Larvicidal Potency

Abstract

The silver nanoparticles were biosynthesized using fungal isolates as well as their mixed cell free filtrate acting as a consortium namely, DS-2 (Penicillium oxalicum), DW-8 (Fusarium hainanense) and DSW-28, respectively. The UV-Visible spectra determined the surface plasmon resonance at 438, 441 and 437 nm for the silver nanoparticles synthesized by DS-2, DW-8 and DSW-28, respectively. The Tauc’s plot analysis disclosed the band gap energy between 2.21 eV to 2.24 eV which depicted their ability to act as a semiconductor. The TEM imaging revealed the spherical shape along with the average particle size of DS-2 as 11.14 ± 2.39 nm and DW-8 as 7.59 ± 1.31 nm whereas that of DSW-28 as 5.73 ± 0.4 nm. Thus, the silver nanoparticles synthesized by DSW-28 were smaller in size than the individual isolates. The XRD pattern of the silver nanoparticles exhibited the crystalline structure corresponding to their peaks. The FTIR spectra indicates the presence of different functional groups on the surface of the synthesized silver nanoparticles. The broad-spectrum antimicrobial activity was exhibited by silver nanoparticles synthesized by DSW-28 against Gram positive, Gram negative bacteria and plant pathogen Fusarium oxysporum than the individual fungal isolates. The DSW-28 synthesized silver nanoparticles also acts as an effective antioxidant by depicting their radical scavenging activity against DPPH. Moreover, the silver nanoparticles synthesized by DSW-28 also inhibited the growth of 4th instar larvae of Aedes aegypti and Culex quinquefasciatus more efficiently than DS-2 and DW-8 in a dose-dependent method. The impressive bioactivity of the silver nanoparticles synthesized by the mixture of cell free filtrate of various fungi acting as a consortium recommends their prospective use in agriculture as well as in biomedical as an antimicrobial, antioxidant and larvicidal agents in future.