Rafaella Costa Bonugli-Santos * 1; Lucia Regina Durrant2; Lara Durães Sette1
e-mail: [email protected]
1Microbial Resources Division, CPQBA – University of Campinas, CEP 13081-970, Campinas, SP, Brazil – E-mail: [email protected]
2 Food Science Department, Faculty of Food Engineering, University of Campinas, Campinas, SP, Brazil
INTRODUCTION
The dyes Remazol Brilliant Blue R (RBBR) and Indigo are one of the most important dyes in
the textile industry and represents an important class of toxic organopollutants. Since the
RBBR is an anthracene derivative, it has been proposed as an efficient screening method for
fungi that are able to degrade recalcitrant pollutants, including aromatic compounds such as
polycyclic aromatic hydrocarbons (PAHs) and synthetic dyes. In addition, fungi derived
from marine environments are emerging as one of the best alternatives in the treatment of
industrial colored effluents mainly due to their salt tolerance. Therefore, the aim of the
present study was to evaluate the decolorization of RBBR and Indigo by Peniophora sp.
isolated from marine sponge Amphimedon viridis.
Keyword: marine-derived fungi, textile dyes decolorization, saline conditions, industrial
effluents.
MATERIAL AND METHODS
Screening of decolorization activity on solid media
200 mg L- of
RBBR and Indigo
Culture media:
Agar MA2
Agar MA2+ 3% NaCl
Agar MA2ASW (artificial sea water)
After 7, 14 and 21 days the fungal growth and the decolorization ability on these plates
were compared with the controls (RBBR-free).
Incubation: 21 days at 28°C
Decolorization ability on liquid medium
Incubation: 7 day
28º C, 140 rpm
Two fungal culture plugs (0.5 cm diameter) from the edge
of the colony were transferred to Erlenmeyer flasks
containing 50 mL of MA2 broth.
A fter 72 h of incubation at 140 rpm and
28°C, RBBR was added to MA2 broth (final
concentration of 500 and 1000 mg L−1).
A liquots of 1 ml from the culture were
taken right after dye addition (zero
time) and in each 24 hours during 7
days.
Samples were centrifuged
(12,074g, 10 min) and the
supernatants were
spectrophotometrically
evaluated :
Color reduction: decolorizing activity was calculated from the decrease in the maximum
absorption peak for RBBR.
Ligninolytic activities: Laccase (ABTS); Manganese peroxidase (phenol red); Lignin
peroxidade (veratryl alcohol).
Decolorization ability on crude enzymatic extract
RBBR (500 ppm) were added to 1 ml clear
supernatant samples obtained from 7-day-old
cultures (mycelia-free culture supernatants
with ligninolytic activity -RBBR-free).
The absorption spectra were read
(range of 200–800 nm) in each 2 h
from time zero and during 24 h of
incubation at 28 °C
RESULTS
After 14 days the dye RBBR was completely decolorizated by Peniophora sp. CBMAI 1063
in the medium without salt:
Control (zero time) 7-day-old 14-day-old Control (RBBR–free)
No RBBR decolorization was obtained in saline conditions;
No decoloration was observed for Indigo dye. In order to stimulate the Indigo decolorization
the fungus was also inoculated at different concentrations of malt extract: MA1 (1% malt
extract) and MA0,5 (0,5% malt extract), but even after 21 days of growth there was no
decolorization;
In generally, RRBR in the liquid medium was decolorized in the 4 th day:
0
10
20
30
40
50
60
70
80
90
100
1 2 3 4 5 6 7
% D
ec
olo
riza
tio
n
Time (day)
500 mg L -1 RBBR
1000 mg L -1 RBBRControl 1 thday 2 th day 3 th day 4 th day 5 th day 6 th day 7 th day
MnP and laccase were detected during the
decolorization process; LiP was not produced;
The highest productions were proportional to the rate of decolorization;
The activity of MnP increased in the presence of RBBR (Control – Free RBBR = 1099 Ul1,
only after 21 days);
0
1000
2000
3000
4000
5000
6000
7000
8000
1 2 3 4 5 6 7
Mn
P (
U L
-1)
Time (day)
0
50
100
150
200
250
300
350
400
450
1 2 3 4 5 6 7
La
cc
as
e (
UL
-1)
Time (day)
500 mg L -1 RBBR1000 mg L -1 RBBR
After 2 h of incubation at 28°C, the crude enzymatic extract showed a decreasing of 50% in
the absorption spectrum, reaching 100% after 24 h;
0,0
2,0
4,0
6,0
350 450 550 580 590 650 750
AB
S
Wavelength (nm)
Absorption spectra during enzymatic decolorization (mycelia-free)
of RBBR
Controle
2 h
4 h
6 h
8 h
24 h
This result showed that there
was a complete removal of the
major visible light absorbance
peak, suggesting that RBBR
decolorization can be take place
in the absence of mycelia.
CONCLUSIONS
Support:
Fungi derived from marine environments have been one of the best alternatives in the
treatment of industrial colored effluents, mainly for application in bioremediation of effluents
with high alkaline and salt concentration (e.g. colored industrial pollutants), once they are
adapted to marine saline conditions;
The results obtained stimulate the development of new studies concerning decolorization and
degradation of synthetic dyes and colored effluents from the textile industries.
