BIOSYNTHESIS OF SILVER NANOPARTICLES USING Saccharomyces boulardii AND STUDY THEIR BIOLOGICAL ACTIVITIES

Fatima H. Sahib*, Nawfal H. Aldujaili and Mohammed M. Alrufae

ABSTRACT

Objective: The objective of the present study is the biosynthesis of silver nanoparticles using probiotic, Saccharomyces boulardii and evaluating their biomedical activity. The biological method of nanoparticles synthesis acquires very important area due to their cost-effective and eco-friendly benefits over chemical and physical methods of synthesis. Methods: AgNPs were biosynthesized by adding silver nitrate (AgNO3) into cell free supernatant of S.boulardii at concentration (10 mM). Results: The PCR was accomplished to molecular identification of S.boulardii using specific primers for (CAG) microsatellite repeat at locus YLR177w, foreword primer (Boul 3) and reverse primer (Boul 4). Biosynthesis of AgNPs was firstly indicated by the colour alteration of reaction mixture from yellow into reddish brown. The characterization completed by XRD, SEM, EDS and AFM. The XRD presented the size of AgNPs was 19nm.The SEM was offered the shape was spherical and homogenous and the size was ranged between 63-100nm. The occurrence of elemental silver was analysed by EDS. The AFM displayed the three dimensional structure of silver nanoparticles and the average diameter was 97.44 nm. Biosynthesized AgNPs showed antibacterial activity against multidrug resistant bacteria(MDR) of both gram positive and gram negative bacteria (S.aureus, S.pyogenes, E.coli, K.pneumoniae, E.aerogens, S.typhi, A.baumannii, P.auroginosa and P.mirabilis). All tested bacterial isolates revealed their ability to form biofilm in the form of biofilm using tube and Congo red method without treated by the nanoparticles except P.mirabils, A.boumanii and E.aerogenes,but when treated with AgNPs this ability was prevented and removed in K.pneumoniae, Ps.auroginosa and C.neoformans. The AgNPs at two concentration 1mg/ml and 2mg/ml bared their antioxidant capacity in vitro by scavenging DPPH free radicles, the largest inhibition titer found in the mixture of DPPH with biogenic AgNPs and supernatant of S.boulardii at concentration 2mg/ml (87.43).

Keywords: Biosynthesis AgNPs, S.boulardii, Antibiofilm, Antimicrobial, Antioxidant Activity.