Biodegradation of Dyes by Laccase
from Isolated Strain Aspergillus flavus
PUF5
Priyanka Ghosh and Uma Ghosh
Abstract Synthetic dyes are very difficult to degrade for their complex structure.
During dyeing process in industry, a huge amount of dyes are lost as effluents. Degradation of these effluents by physical and chemical processes is the most problematic
issues nowadays. Enzymatic oxidation of these dyes using oxidoreductase such as
laccase has received a great attention in recent years for decolorization of dyes in
effluent. In the present study, an isolated fungus Aspergillus flavus PUF5 was used
to produce laccase enzyme and employed for degradation of five commercially used
textile dyes, phenol red, methyl orange, malachite green, bromophenol blue and
Congo red. The investigations were made with the effect of redox mediators (1 mM),
temperature (25–45 °C), pH (4–8) and incubation time (0–24 h) in the dye decolorization by laccase. Highest efficiency in dye decolorization was found with redox mediator 1-hydroxy-benzotriazole (HBT). The interactions between four variable factors
were statistically studied using response surface methodology. Optimized states of
selected variables were dye concentration (6.04 µM), enzyme concentration (78.8
U/ml), pH (5.6) and redox mediator (1.07 mM) with predicted and observed activity
of laccase 85.94 and 86.3 U/ml, respectively. These results suggest that laccase is a
potential enzyme for removal of dyes present in wastewater of textile industry.
Keywords Aspergillus flavus PUF5 · Laccase · Textile dyes · RSM · HBT
1 Introduction
Laccases (benzenediol: oxygen oxidoreductase, EC 1.10.3.2) is a multicopper
oxidase that reduces molecular oxygen to water and simultaneously performs oneelectron oxidation in a large range of inorganic and organic substrates, including
P. Ghosh · U. Ghosh (B)
Food Technology & Biochemical Engineering Department, Jadavpur University, Kolkata,
West Bengal 700032, India
e-mail: ughoshftbe@yahoo.co.in
P. Ghosh
e-mail: priyankaghsh288@yahoo.in
© Springer Nature Singapore Pte Ltd. 2021
D. Ramkrishna et al. (eds.), Advances in Bioprocess Engineering and Technology,
Lecture Notes in Bioengineering,
https://doi.org/10.1007/978-981-15-7409-2_11
109
from Isolated Strain Aspergillus flavus
PUF5
Priyanka Ghosh and Uma Ghosh
Abstract Synthetic dyes are very difficult to degrade for their complex structure.
During dyeing process in industry, a huge amount of dyes are lost as effluents. Degradation of these effluents by physical and chemical processes is the most problematic
issues nowadays. Enzymatic oxidation of these dyes using oxidoreductase such as
laccase has received a great attention in recent years for decolorization of dyes in
effluent. In the present study, an isolated fungus Aspergillus flavus PUF5 was used
to produce laccase enzyme and employed for degradation of five commercially used
textile dyes, phenol red, methyl orange, malachite green, bromophenol blue and
Congo red. The investigations were made with the effect of redox mediators (1 mM),
temperature (25–45 °C), pH (4–8) and incubation time (0–24 h) in the dye decolorization by laccase. Highest efficiency in dye decolorization was found with redox mediator 1-hydroxy-benzotriazole (HBT). The interactions between four variable factors
were statistically studied using response surface methodology. Optimized states of
selected variables were dye concentration (6.04 µM), enzyme concentration (78.8
U/ml), pH (5.6) and redox mediator (1.07 mM) with predicted and observed activity
of laccase 85.94 and 86.3 U/ml, respectively. These results suggest that laccase is a
potential enzyme for removal of dyes present in wastewater of textile industry.
Keywords Aspergillus flavus PUF5 · Laccase · Textile dyes · RSM · HBT
1 Introduction
Laccases (benzenediol: oxygen oxidoreductase, EC 1.10.3.2) is a multicopper
oxidase that reduces molecular oxygen to water and simultaneously performs oneelectron oxidation in a large range of inorganic and organic substrates, including
P. Ghosh · U. Ghosh (B)
Food Technology & Biochemical Engineering Department, Jadavpur University, Kolkata,
West Bengal 700032, India
e-mail: ughoshftbe@yahoo.co.in
P. Ghosh
e-mail: priyankaghsh288@yahoo.in
© Springer Nature Singapore Pte Ltd. 2021
D. Ramkrishna et al. (eds.), Advances in Bioprocess Engineering and Technology,
Lecture Notes in Bioengineering,
https://doi.org/10.1007/978-981-15-7409-2_11
109