Use of Fungal Laccases and Peroxidases for Enzymatic Treatment of Wastewater Containing Synthetic Dyes - Green Chemistry for Dyes Removal from Wastewater - page 217

of substituted aromatic rings was also observed. Cripps et al. [47] also
showed decolorization of other azo dyes, including Acid Orange 7, Acid
Orange 6, and Direct Red 28, as well as an heterocyclic dye Azure B using
P. chrysosporium .

6.3.2 Other White Rot Fungi

In addition to P. chrysosporium , a large number of white rot fungi have
been tested for their ability to decolorize synthetic dyes in the 2000s. Such
fungi as T. ( Coriolus ) versicolor [25,48-53], T. hir s ut a [54-56], Bjerkandera
adusta [25,57-60], Bjerkandera sp. [61], Phanerochaete sordida [62],
Pleurotus ostreatus [34,63-66], P. florida [55,67], P. s a j o r - c a j u [68,69],
P. l a b e l l a t u s [70], Pycnoporus sanguineus [69,71], Funalia trogii [52], Irpex
lacteus [34,72], I. flavus [73], Lentinula edodes [74,75], Phlebia spp. [73],
Ganoderma lucidum [66], and Ganoderma sp. [76] have been evaluated for
this purpose. Many authors have reported that some of these fungi, such
as B. adusta and P. ostreatus, showed better performance than P. c h r y s o -
sporium in synthetic dye degradation and decolorization because of their
independence from nitrogen regulation as well as their so-called “hybrid”
enzyme (also called versatile peroxidase and “dye-decolorizing peroxidase”
(DyP) [77]) that has a wider substrate specificity [61,78]. See Section 6.5
for more description of these enzymes. Several anthraquinone dyes, such
as Poly R-478 and Reactive Blue 19, were often used as a standard model
dyes to evaluate the decolorization capacity of white rot fungi in many
studies [34,51,60,61,73,79], while decolorization of other classes of dyes,
such as azo [25,52,59,80-82], phthalocyanine [25], triarylmethane [81],
and indigoid dyes [69,81], was also successfully demonstrated.
In addition to the strains that had been maintained in culture collec-
tions such as the American Type Culture Collection (ATCC), many new
wild strains were isolated more recently in many countries such as India
[67,76,80], Pakistan [66], Zimbabwe [83], Tanzania [70], Argentina [84],
Brazil [69], and Singapore [51], and were tested for their dye-decolorizing
capability. As with other microorganisms, the white rot fungi are distrib-
uted globally and universally. Therefore, there is still a possibility of discov-
ering more efficient species and strains that can be used in this application.

6.3.3 Bioreactors and Real Wastewater Treatment

A majority of these fungal decolorization studies were performed in vitro or
in small batch reactors (i.e., culture flasks) to prove the concept. However,