The Biosynthesis of Silver Nanoparticle by Seratia AQ5-NT39 for Antibacterial Screening towards Streptococcus agalactiae

Abstract

Aquaculture industry is currently facing many obstacles in meeting the demands and one of the main factors is disease outbreaks in fish farms. Specifically among the majority second most cultivated fish in Malaysia, red hybrid tilapia fish farms due to it prominent causative agent, Streptococcus agalactiae. The overuse of antibiotics to control these infections has led to the emergence of antimicrobial resistance, necessitating the search for alternative treatments. This study explores the potential of silver nanoparticles (AgNPs) synthesized by the marine bacterium Serratia sp. AQ5-NT39 as an antibacterial agent against S. agalactiae. AgNPs were biosynthesized through the extracellular production by Serratia sp. AQ5-NT39, leveraging the bacterium's natural ability to tolerate heavy metals. The antibacterial properties of these biosynthesized AgNPs were evaluated using in vitro methods, the Kirby-Bauer disk diffusion test. The AgNPs exhibited an inhibition zone of 3.67±0.29 mm compared to the positive control with a zone of inhibition 4.97±0.01 mm. This research demonstrates the promising potential of biosynthesized AgNPs from Serratia sp. AQ5-NT39 as a sustainable alternative to antibiotics in the aquaculture industry. Further studies will focus on optimizing the synthesis and application of AgNPs to enhance their antibacterial efficacy and ensure their safety for widespread use.