Antimicrobial Activity of Silver Nanoparticles Biosynthesized by the Fungus Byssochlamys spectabilis Against Actinomyces dentalis

Abstract Background: Over time, pathogenic microorganisms have become more resistant to antimicrobials, and this is a risk to human health. Therefore, alternatives that are more effective against these pathogens must be searched for. Objectives: This study, which was completed in the College of Dentistry and College of Science at the University of Babylon, aimed to produce silver nanoparticles in a biological method using a fungal extract of this Byssochlamys spectabilis fungus, for the first study in Iraq. Materials and Methods: Where it was studied properties its morphology, microscopic, and molecular diagnosis by PCR and documented in the International Information Bank (NCBI) under the isolate name “Al-Rahman” and has Accession number (MN318956.1), as well as studying the fit environmental conditions, where it gave The best growth is at 27°C temperature, pH = 6.5, and the best type of culture medium is PDA. This fungus was used as a reducing agent, very fitting for the synthesis of AgNPs and its use as an antimicrobial. Results: The color change of AgNPs from yellow to ruddy brown was the principal Sign of biosynthesis. UV-noticeable spectrophotometry was utilized to portray biosynthetic nanoparticles and the greatest ingestion pinnacle of the nanoparticles (420 nm) was noticed. The size and distribution of nanoparticles were determined by using scanning electron microscopy (atomic force microscopy AFM and transmission electron microscopy TEM), and the shape was circular and homogeneous, the size varied from (10.49‐16.42 nm) to test these fabricated nanomaterials. The isolated Actinomyces dentalis from patients who had periodontitis and who visited specialized dental centers and private clinics at the University of Babylon in the College of Dentistry, after culturing this sample in the laboratory. Different concentrations of the nanomaterial (31.25, 62.5, 125, 250, and 500 µg) were prepared and its effect as an inhibitory agent against this isolate was studied. It was 125 µg the best concentrate to kill A. dentalis . Conclusion: Silver nanoparticles biologically synthesized by B. spectabilis were able to inhibit bacterial growth of strain of medical importance, which was demonstrated by obtaining inhibition percentages greater than 20 cm of A. dentalis .