Role of catalytic protein and stabilising agents in the transformation of Ag ions to nanoparticles byPseudomonas aeruginosa.
Biological routes of synthesising metal nanoparticles (NPs) using microbes have been gaining much attention due to their low toxicity and eco-friendly nature. Pseudomonas aeruginosa JP2 isolated from metal contaminated soil was evaluated towards extracellular synthesis of silver NPs (AgNPs). Cell-free extract (24 h) of the bacterial isolate was reacted with AgNO3for 24 h in order to fabricate AgNPs. Preliminary observations were recorded in terms of colour change of the reaction mixture from yellow to greyish black. UV-visible spectroscopy of the reaction mixture has shown a progressive increase in optical densities that correspond to peaks near 430 nm, depicting reduction of ionic silver (Ag+) to atomic silver (Ag0) thereby synthesising NPs. X-ray diffraction spectra exhibited the 2θ values to be 38.4577° confirming the crystalline and spherical nature of NPs [9.6 - 26.7 (Ave. = 17.2 nm)]. Transmission electron microscopy finally confirmed the size of the particles varying from 5 to 60 nm. Moreover, rhamnolipids and proteins were identified as stabilising molecules for the AgNPs through Fourier transform-infrared spectroscopy. Characterisation of bacterial crude and purified protein fractions confirmed the involvement of nitrate reductase (molecular weight 66 kDa and specific activity = 3.8 U/mg) in the Synthesis of AgNPs.
Department of Microbiology, Quaid-i-Azam University Islamabad, Islamabad, Pakistan.
Jafar
J
Ali
CIRBS, International Islamic University, Islamabad, Pakistan.
Abdul
A
Hameed
Department of Microbiology, Quaid-i-Azam University Islamabad, Islamabad, Pakistan.
Safia
S
Ahmed
Department of Microbiology, Quaid-i-Azam University Islamabad, Islamabad, Pakistan.
Muhammad Ishtiaq
MI
Ali
Department of Microbiology, Quaid-i-Azam University Islamabad, Islamabad, Pakistan.
Shama
S
Zainab
Department of Microbiology, Quaid-i-Azam University Islamabad, Islamabad, Pakistan. naeemali95@gmail.com.
Naeem
N
Ali
Appl Environ Microbiol. 2007 Mar;73(6):1712-20
17261510
Colloids Surf B Biointerfaces. 2011 Jun 1;84(2):462-6
21353501
Anal Bioanal Chem. 2008 Jul;391(5):1579-90
18320178
Adv Colloid Interface Sci. 2010 Apr 22;156(1-2):1-13
20181326
Colloids Surf B Biointerfaces. 2011 Apr 1;83(2):291-8
21185161
J Microbiol Biotechnol. 2010 Jul;20(7):1061-8
20668398
Int J Nanomedicine. 2011;6:569-74
21674013
Colloids Surf B Biointerfaces. 2009 Jun 1;71(1):133-7
19269142
Langmuir. 2011 Dec 20;27(24):15268-74
22026721
J Biochem. 1977 Dec;82(6):1663-71
202590
Nanotechnology. 2008 Feb 27;19(8):085602
21730726
Biometals. 2009 Apr;22(2):235-42
18769871
Biotechnol Lett. 2007 Mar;29(3):439-45
17237973
J Bacteriol. 2002 Mar;184(5):1314-23
11844760
Colloids Surf B Biointerfaces. 2009 Nov 1;74(1):328-35
19716685
Environ Sci Technol. 2007 Jul 15;41(14):5114-9
17711232
Nanoscale. 2011 Feb;3(2):635-41
21088776
Toxicol In Vitro. 2011 Aug;25(5):1097-105
21419840
J Nanobiotechnology. 2011 Dec 07;9:56
22152042