352
N. B. Raj et al.
Effect of Metal Concentration
In a study conducted by Prasad and Jha (2010), two bacterial species namely Lactobacillus sp. and Saccharomyces cerevisiae were used to determine the effect of CdCl 2
(0.25 M) on CdSNPs synthesis at 60 °C for 10–20 min. Results indicated that, the
particle size was found to be 4.93 ± 0.23 nm, 3.57 ± 0.21 nm in Lactobacillus and
yeast, respectively. Further, the authors explained that, the particle size in yeast was
less because it has a good detoxification machinery mechanisms and organization at
the cellular level than Lactobacillus sp., a prokaryote. In another study, sphericalshaped iron nanoparticles with particle size ranging between 10 and 24.6 nm were
synthesized from Aspergillus oryzae TFR9 using salt solution of FeCl 3 (0.001 M) at
28 °C for 12 h (Tarafdar and Raliya 2013). Aspergillus tubingensis TFR-3 utilized
10
−3 M of Mg(NO 3 ) 2 ·6H 2 O salt solution at 28° C for 48 h to synthesize magnesium oxide nanoparticle with 5.8 nm (Raliya et al. 2014a, b). Sheikhloo (2011b)
employed 1 mM aqueous HAuCl 4 solution with pH 2.5 at 27–29 °C for 72 h to
synthesize intracellular AuNPs having spherical, triangle and rod shapes with the
size range of 5–100 nm using the fungus Penicillium chrysogenum. A rapid approach
for the biosynthesis of AuNPs by Trichoderma viride MTCC 5661 and Hypocrea
lixii MTCC 5659 using 250 mg/L Chloroauric 5 acid was reported by Mishra et al.
(2014b). Gold nanoparticles with 20–30 and 120 nm in size were synthesized within
10 min at 30 °C in T. viride, which was similar to Hypocrea lixii with 20 nm size
AuNPs but at 100 °C, respectively.
Abdel Rahim et al. (2017) synthesized 2.86 nm-sized AgNPs at 10 mM AgNO 3 ,
while bigger sizes of 54.67 and 14.23 nm were synthesized at 100 and 1 mM, respectively, from Rhizopus stolonifer. Salunkhe et al. (2011) synthesized spherical-shaped
AgNPs using Cochliobolus lunatus with size ranging from 5 to 100 nm at pH 7 and
28 °C using 635 ppm silver in. In another study, Fayaz et al. (2010) synthesized
spherical-shaped, 2–4 nm size AgNPs in T. viride using 1 mM Ag
+ in dark condition at 40 °C. Aziz et al. (2016) reported spherical-shaped 5–15 nm size AgNPs
using 1 mM silver nitrate in Mucor hiemalis. Barabadi et al. (2017) synthesized
spherical-shaped AgNPs in Penicillium aculeatum with the average particle size of
60 nm at 28 °C for 24 h using 3 mM HAuCl 4 . Also, Candida albicans mediated
spherical-shaped AgNPs with 20–40 and 60–80 nm size, and non-spherical AuNPs
were obtained using 1 mM aqueous HAuCl 4 in 24 h (Chauhan et al. 2011). Various
concentrations of silver nitrate (1–10 mM), pH (1–10) and temperature (30–80 °C)
conditions were investigated for AgNPs synthesis in Guignardia mangiferae. Among
the conditions, 1 mM silver nitrate was found to be optimum and produced sphericalshaped AgNPs with 5–30 nm size at pH 7 and 30 °C within 12 h (Balakumaran et al.
2015). Concordant results were obtained with 1 mM concentration of silver nitrate
for AgNPs synthesis in E. nigrum and Penicillium sp (Qian et al. 2013; Singh et al.
2014).
In another study, plant pathogenic fungus Helminthosporum solani was treated
with 1 mM aqueous solution of chloroaurate ions at 37 ± 1 °C for 72 h to produce
a diverse mixture of intracellular AuNPs with the size ranging from 2 to 70 nm. A
plurality of polydisperse spheres (44%), but a significant number are homogeneously
N. B. Raj et al.
Effect of Metal Concentration
In a study conducted by Prasad and Jha (2010), two bacterial species namely Lactobacillus sp. and Saccharomyces cerevisiae were used to determine the effect of CdCl 2
(0.25 M) on CdSNPs synthesis at 60 °C for 10–20 min. Results indicated that, the
particle size was found to be 4.93 ± 0.23 nm, 3.57 ± 0.21 nm in Lactobacillus and
yeast, respectively. Further, the authors explained that, the particle size in yeast was
less because it has a good detoxification machinery mechanisms and organization at
the cellular level than Lactobacillus sp., a prokaryote. In another study, sphericalshaped iron nanoparticles with particle size ranging between 10 and 24.6 nm were
synthesized from Aspergillus oryzae TFR9 using salt solution of FeCl 3 (0.001 M) at
28 °C for 12 h (Tarafdar and Raliya 2013). Aspergillus tubingensis TFR-3 utilized
10
−3 M of Mg(NO 3 ) 2 ·6H 2 O salt solution at 28° C for 48 h to synthesize magnesium oxide nanoparticle with 5.8 nm (Raliya et al. 2014a, b). Sheikhloo (2011b)
employed 1 mM aqueous HAuCl 4 solution with pH 2.5 at 27–29 °C for 72 h to
synthesize intracellular AuNPs having spherical, triangle and rod shapes with the
size range of 5–100 nm using the fungus Penicillium chrysogenum. A rapid approach
for the biosynthesis of AuNPs by Trichoderma viride MTCC 5661 and Hypocrea
lixii MTCC 5659 using 250 mg/L Chloroauric 5 acid was reported by Mishra et al.
(2014b). Gold nanoparticles with 20–30 and 120 nm in size were synthesized within
10 min at 30 °C in T. viride, which was similar to Hypocrea lixii with 20 nm size
AuNPs but at 100 °C, respectively.
Abdel Rahim et al. (2017) synthesized 2.86 nm-sized AgNPs at 10 mM AgNO 3 ,
while bigger sizes of 54.67 and 14.23 nm were synthesized at 100 and 1 mM, respectively, from Rhizopus stolonifer. Salunkhe et al. (2011) synthesized spherical-shaped
AgNPs using Cochliobolus lunatus with size ranging from 5 to 100 nm at pH 7 and
28 °C using 635 ppm silver in. In another study, Fayaz et al. (2010) synthesized
spherical-shaped, 2–4 nm size AgNPs in T. viride using 1 mM Ag
+ in dark condition at 40 °C. Aziz et al. (2016) reported spherical-shaped 5–15 nm size AgNPs
using 1 mM silver nitrate in Mucor hiemalis. Barabadi et al. (2017) synthesized
spherical-shaped AgNPs in Penicillium aculeatum with the average particle size of
60 nm at 28 °C for 24 h using 3 mM HAuCl 4 . Also, Candida albicans mediated
spherical-shaped AgNPs with 20–40 and 60–80 nm size, and non-spherical AuNPs
were obtained using 1 mM aqueous HAuCl 4 in 24 h (Chauhan et al. 2011). Various
concentrations of silver nitrate (1–10 mM), pH (1–10) and temperature (30–80 °C)
conditions were investigated for AgNPs synthesis in Guignardia mangiferae. Among
the conditions, 1 mM silver nitrate was found to be optimum and produced sphericalshaped AgNPs with 5–30 nm size at pH 7 and 30 °C within 12 h (Balakumaran et al.
2015). Concordant results were obtained with 1 mM concentration of silver nitrate
for AgNPs synthesis in E. nigrum and Penicillium sp (Qian et al. 2013; Singh et al.
2014).
In another study, plant pathogenic fungus Helminthosporum solani was treated
with 1 mM aqueous solution of chloroaurate ions at 37 ± 1 °C for 72 h to produce
a diverse mixture of intracellular AuNPs with the size ranging from 2 to 70 nm. A
plurality of polydisperse spheres (44%), but a significant number are homogeneously