Microbial Enzymes in Nanotechnology …
199
solution that maximally absorbed at 550 nm in the UV–Vis spectrum and TEM
showed the AuNPs to be highly monodispersed having size variation of 22–39 nm.
Laccase was observed to perform the reduction course as a protein and not as an
active enzyme because laccase in its active form only catalyzed the oxidation and
lost its activity once exposed to increased temperature or gamma radiation as the
nature of its protein structure was broken down, thus exposing its various amino
acids. According to Faramarzi and Forootanfar (2011), purified laccase generated by
Paraconiothyrium variabile was employed for biogenic synthesis of AuNPs, and the
nature of the AuNPs was characterized. UV–vis spectrum showed peak at 530 nm
related to surface plasmon absorbance of AuNPs, and TEM image of AuNPs revealed
well-dispersed AuNPs with sizes ranging from 71–266 nm as also displayed by the
laser light scattering technique. Sanghi et al. (2011) reported the extracellular and
intracellular biosynthesis of AuNPs using laccase and ligninase obtained from Phanerochaete chrysosporium, respectively. Characterization via atomic force microscopy
(AFM) displayed that the biosynthesized AuNPs was spherical having size varying
from 10 to 100 nm. Wadhwani et al. (2018) reported the biogenic synthesis of AuNPs
using lignin peroxidase, purified by DEAE-cellulose anion exchange and Biogel P150 gel filtration chromatography from the cell supernatant of Acinetobacter sp.
SW30. The lignin peroxidase was a monomeric enzyme with molecular weight of
97.4 KDa, and the resultant nanoparticles biosynthesized were spherical crystalline
AuNPs with mean size 10 ± 2 nm. Elegbede et al. (2020) reported the novel relevance
of xylanases produced by strains of Aspergillus niger L3 (NEA) and Trichoderma
longibrachiatum L2 (TEA) in the ecological-friendly synthesis of AuNPs for biomedical applications. The spherical and flower-shaped AuNPs with sizes varying from
4.88–123.99 nm as shown by TEM were a purple color solution which displayed
absorbance at 545 and 560 nm for NEA-AuNPs and TEA-AuNPs, respectively,
attributable to their surface plasmon resonance. The biosynthesized AuNPs had good
antimicrobial against clinical fungal and bacterial isolates, antioxidant (DPPH and
H 2 O 2 ), thrombolytic and anticoagulation activities.
Bharde et al. (2007) revealed the important role of protease in the shape controlled
environmental-friendly synthesis of gold nanoparticles. The results obtained indicated the probable responsibility of protease induced with bovine serum albumin
(BSA) for the reduction of gold ions and consequent formation of AuNPs. The
function of protease in the synthesis of AuNPs was further clarified by utilizing
commercial protease from fungus A. Saitoi for the synthesis resulting in color development to pink from pale-yellow after about 8 h of reaction which indicated the
creation of AuNPs which were established to be hexagonal and triangular structured using TEM. However, reacting the culture supernatant containing BSA with
1 mM HAuCl 4 in the attendance of pepstatin (protease inhibitor) did not lead to
formation of AuNPs even after 12 h of reaction; thus, establishing that protease was
accountable for the bioreduction. Moreover, the synthesis of the anisotrophic AuNPs
within 8 h reported was observed to be a noteworthy development over synthesis of
anisotrophic AuNPs which have been well reported to take about 24 h. The existence of the enzyme was observed to speed up the reaction rate which can make
them applicable catalyst even for the synthesis of nanomaterials. Mishra and Sardar
199
solution that maximally absorbed at 550 nm in the UV–Vis spectrum and TEM
showed the AuNPs to be highly monodispersed having size variation of 22–39 nm.
Laccase was observed to perform the reduction course as a protein and not as an
active enzyme because laccase in its active form only catalyzed the oxidation and
lost its activity once exposed to increased temperature or gamma radiation as the
nature of its protein structure was broken down, thus exposing its various amino
acids. According to Faramarzi and Forootanfar (2011), purified laccase generated by
Paraconiothyrium variabile was employed for biogenic synthesis of AuNPs, and the
nature of the AuNPs was characterized. UV–vis spectrum showed peak at 530 nm
related to surface plasmon absorbance of AuNPs, and TEM image of AuNPs revealed
well-dispersed AuNPs with sizes ranging from 71–266 nm as also displayed by the
laser light scattering technique. Sanghi et al. (2011) reported the extracellular and
intracellular biosynthesis of AuNPs using laccase and ligninase obtained from Phanerochaete chrysosporium, respectively. Characterization via atomic force microscopy
(AFM) displayed that the biosynthesized AuNPs was spherical having size varying
from 10 to 100 nm. Wadhwani et al. (2018) reported the biogenic synthesis of AuNPs
using lignin peroxidase, purified by DEAE-cellulose anion exchange and Biogel P150 gel filtration chromatography from the cell supernatant of Acinetobacter sp.
SW30. The lignin peroxidase was a monomeric enzyme with molecular weight of
97.4 KDa, and the resultant nanoparticles biosynthesized were spherical crystalline
AuNPs with mean size 10 ± 2 nm. Elegbede et al. (2020) reported the novel relevance
of xylanases produced by strains of Aspergillus niger L3 (NEA) and Trichoderma
longibrachiatum L2 (TEA) in the ecological-friendly synthesis of AuNPs for biomedical applications. The spherical and flower-shaped AuNPs with sizes varying from
4.88–123.99 nm as shown by TEM were a purple color solution which displayed
absorbance at 545 and 560 nm for NEA-AuNPs and TEA-AuNPs, respectively,
attributable to their surface plasmon resonance. The biosynthesized AuNPs had good
antimicrobial against clinical fungal and bacterial isolates, antioxidant (DPPH and
H 2 O 2 ), thrombolytic and anticoagulation activities.
Bharde et al. (2007) revealed the important role of protease in the shape controlled
environmental-friendly synthesis of gold nanoparticles. The results obtained indicated the probable responsibility of protease induced with bovine serum albumin
(BSA) for the reduction of gold ions and consequent formation of AuNPs. The
function of protease in the synthesis of AuNPs was further clarified by utilizing
commercial protease from fungus A. Saitoi for the synthesis resulting in color development to pink from pale-yellow after about 8 h of reaction which indicated the
creation of AuNPs which were established to be hexagonal and triangular structured using TEM. However, reacting the culture supernatant containing BSA with
1 mM HAuCl 4 in the attendance of pepstatin (protease inhibitor) did not lead to
formation of AuNPs even after 12 h of reaction; thus, establishing that protease was
accountable for the bioreduction. Moreover, the synthesis of the anisotrophic AuNPs
within 8 h reported was observed to be a noteworthy development over synthesis of
anisotrophic AuNPs which have been well reported to take about 24 h. The existence of the enzyme was observed to speed up the reaction rate which can make
them applicable catalyst even for the synthesis of nanomaterials. Mishra and Sardar