IMBIV   05474
INSTITUTO MULTIDISCIPLINARIO DE BIOLOGIA VEGETAL
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
BIOSYNTHESIS OPTIMIZATION OF TRANSITION METAL NANOPARTICLES
Autor/es:
K. CRESPO ANDRADA; J. BARONETTI; M. QUINTEROS; M.A. DA SILVA; PÁEZ PL; M.G. PARAJE
Lugar:
Cordoba
Reunión:
Congreso; Congreso Argentino de Microbiología General (SAMIGE); 2015
Institución organizadora:
samige
Resumen:
The Metal nanoparticles (Nps) have gained interest in various areas of science and technology. Microorganisms, such asbacteria and fungi, have been exploited to synthesize these particles. Nonetheless, bacteria are preferred for Nps productionover eukaryotic microorganisms due to easy of handling and genetic manipulation. The aim of this study was to optimize theintra and extracellular biosynthesis (IB and EB) of iron and zinc metallic Nps using bacterial strains such as Escherichia coli andPseudomonas aeruginosa by modifying several physical- chemical parameters. E. coli (ATCC 25922) and P. aeruginosa (ATCC27853) were grown in Tryptic Soy Broth (TSB) for 18 h, at 37 °C kept under continuous agitation in an orbital shaker (200 rpm).For IB, 15 mL of this culture were mixed with 1.5 mL of the different metallic solution [FeSO4 (II), FeCl3 (III), Fe Citrate (III)),ZnSO4 (II), ZnCl2 (II)] and incubated under shaking. Then, the solution was sonicated at 80W for 30 minutes and centrifuged at8500 rpm for 5 min. For EB, the culture was previously centrifuged before mixing with the saline solutions and the sonicationprocedure was avoided. Different conditions of salt concentration (1 and 10 mM), incubation time (24, 48 and 72 h), temperature(37-50 °C) and pH (7 and 9) were assayed. Nps production was monitored by UV-visible in 200-800 nm range, observing thesurface plasmon resonance (SPR). For E. coli, Fe Nps were formed both intra- and extracellularly at 1mM. However thisproduction was not observed at 10 mM. The SPR peak was observed at 275 nm. The obtained solution presented a dark browncolor. For P. aeruginosa, iron Nps were obtained only extracellularly at 1mM. Nps formation was detected with Fe Citrate,FeSO4 in E. coli and FeCl3 in P. aeruginosa by increasing the pH to 9. The incubation times were from 24 to 72 h and notsignificant differences were observed in the SPR peak. In E. coli, a peak was observed at 275 nm both for intra- andextracellular synthesis with ZnCl2 . The solution had a white color. With ZnSO4 , the EB was only observed. In contrast, Zn Npswere synthesized extracellularly with both salts in P. aeruginosa, the peak was observed at 425nm and the solution presented agreenish-yellow color. Several parameters for the Fe and Zn Nps biosynthesis were optimized in E. coli and P. aeruginosastrains. The optimal conditions were obtained with P. aeruginosa at EB with FeCl3 and ZnSO4 1 mM at 37 °C for 48 h. Futureperspective: Potential biological activity of biosynthesized Nps will be evaluated by determining the antimicrobial andanticoagulant activity as well as application of bioremediation technology to contaminated soil and water systems.