Biosynthesis of Silver Nanoparticles from Bacillus licheniformis TT01 Isolated from Quail Manure Collected in Vietnam

Lam Van Tan,Thanh Tran,Van Doan Thi

doi:10.3390/pr9040584

Abstract

Silver nanoparticles (AgNPs) find a wide range of use in many fields, and the biosynthesis of AgNPs via biological routines has recently gained currency. In this study, Bacillus licheniformis TT01 strain was isolated from quail feces collected in Vietnam and evaluated for its ability to synthesize AgNPs. Through visual confirmation and ultraviolet and visible (UV–Vis) spectrum analysis, we found that the biosynthesis of AgNPs was realized in the process in which biomass of B. licheniformis TT01 was incubated with AgNO3 solution. Obtained AgNPs were then assayed for antibacterial activity against three species of bacteria, namely Escherichia coli, Bacillus cereus and Ralstoniasolanacearum, showing better inhibitory action than the AgNO3 solution and the bacterial extracellular fluid. The minimum inhibitory concentration (MIC) of AgNP solution was 206 ppm against E. coli and R. solanacearum and 343.3 against B. cereus. X-ray diffraction (XRD) and transmission electron microscopy (TEM) revealed that the obtained AgNPs had a spherical shape and sizes ranging from 2 to 22 nm, in which particles from 2 to 10 nm appeared with the highest frequency.

Highlights

Silver nanoparticles (AgNPs) offer a great bioavailability in medical applications due to their capability to permeate human organs and penetrate cell membranes [1,2,3,4]
The B. licheniformis TT01 strain was cultured in a liquid LB medium at a constant temperature of 40 ◦ C, with pH adjusted to the range from 7.0 to 7.5 over 15 to 25 h [30]
The results indicated that only the use of B. licheniformis biomass resulted in successful AgNP synthesis

Summary

Introduction

Silver nanoparticles (AgNPs) offer a great bioavailability in medical applications due to their capability to permeate human organs and penetrate cell membranes [1,2,3,4]. AgNP synthesis methods, including chemical, physical and biological procedures. A typical technique for the chemical routine is the use of agents to reduce silver ions to metals [5]. The nanoparticles produced by this method might have a wide size distribution, ranging from a few nanometers to 100 nm [5,7]. High-energy electromagnetic waves such as gamma rays, ultraviolet rays and lasers are used to reduce silver ions to metals. Under the effect of electromagnetic waves, there are many processes of converting solvents and additives in the solvent to produce chemical radicals that reduce ions to metals [8,9]. It is possible to use the electrolysis method combined with ultrasonic nanoparticle generation [10] or bacteria as metal-deionizing agents [11]

Methods

Results

Conclusion