2011; Helmfrid et al. 2012; Kramer et al. 2012; El Majidi et al. 2013) especially for
coplanar PCBs (not substituted at the ortho ring positions), which exhibit dioxin-like
toxicity features (US EPA 2004; Van den Berg et al. 2006). Therefore, the cleanup of
PCB-contaminated sites has become a global priority.
A large number of LFs belonging to Basidiomycota phylum were tested in
laboratory-scale model liquid systems for their ability to degrade technical PCB
mixtures or single PCB congeners, namely Phanerochaete chrysosporium (Eaton
1985; Thomas et al. 1992; Vyas et al. 1994; Yadav et al. 1995; Kamei et al. 2006a),
T. versicolor (Zeddel et al. 1993; Vyas et al. 1994; Cloete and Celliers 1999),
Lentinus edodes (Ruiz-Aguilar et al. 2002), P. ostreatus (Kubátová et al. 2001;
Čvančarová et al. 2012), Grifola frondosa (Seto et al. 1999), Coriolopsis polyzona
(Vyas et al. 1994; Novotný et al. 1997), Phlebia brevispora (Kamei et al. 2006b),
I. lacteus (Čvančarová et al. 2012), B. adusta (Beaudette et al. 1998; Čvančarová
et al. 2012), Pycnoporus cinnabarinus (Čvančarová et al. 2012), Phanerochaete
magnoliae (Čvančarová et al. 2012). Generally, all these studies confirmed that the
extent of degradation significantly decreases with increasing chlorine content.
Moreover, the mechanisms by which fungi degrade PCBs were widely investigated (Beaudette et al. 1998; Krčmář et al. 1999; Kamei et al. 2006a, 2006b; Takagi
et al. 2007; Čvančarová et al. 2012; Stella et al. 2017).
Nevertheless, few studies investigated the ability of WRFs to degrade PCBs in
actual contaminated soils (Borazjani et al. 2005; Federici et al. 2012; Stella et al.
2017; Siracusa et al. 2017). Borazjani et al. (2005) tested different treatments for the
remediation of soil contaminated by the technical PCB mixtures Aroclor 1242, 1248,
and 1260. The highest degradation extent for the higher chlorinated mixture 1260
was observed when kenaf (a lignocellulosic substrate) inoculated with the white-rot
fungus P. chrysosporium was mixed with soil (3% w/w). Another study demonstrated that 33.6% of Aroclor 1260 depletion and 23.2% of dechlorination was
reached in 60 days by a bioaugmentation approach based on the use of maize
stalk-immobilized fungus Lentinus tigrinus (Federici et al. 2012).
The PCB-degrading abilities of two white-rot fungi, namely P. ostreatus and
I. lacteus, were also assessed in long-term PCB-contaminated soils the contamination of which was mostly caused by the presence of Delor 103 PCB mixture (Stella
et al. 2017). Three soil samples, which differed in their PCB contents, were selected
for microcosm preparation: bulk soil, topsoil, and rhizosphere soil. The soils were
mixed with either P. ostreatus- or I. lacteus-colonized lignocellulosic substrate
(LS) for bioaugmentation treatments to reach a final soil:LS mass ratio of 5:1
(w/w) and incubated for 12 weeks. The greatest PCB depletion (50.5%) was
achieved in the P. ostreatus-augmented rhizosphere soil, whilst I. lacteus led to
the degradation of 30.3% of the original amount after 12 weeks of the incubation. On
the other hand, for the most contaminated soil (bulk soil), no significant decrease in
the PCB concentration was observed within the first 6 weeks of the incubation
regardless of the treatment employed. Moderate removals (18.5 and 19.3%) were
observed only after 12 weeks in P. ostreatus- and I. lacteus-augmented microcosms,
respectively.
22 Mycoremediation of Contaminated Soils
449
coplanar PCBs (not substituted at the ortho ring positions), which exhibit dioxin-like
toxicity features (US EPA 2004; Van den Berg et al. 2006). Therefore, the cleanup of
PCB-contaminated sites has become a global priority.
A large number of LFs belonging to Basidiomycota phylum were tested in
laboratory-scale model liquid systems for their ability to degrade technical PCB
mixtures or single PCB congeners, namely Phanerochaete chrysosporium (Eaton
1985; Thomas et al. 1992; Vyas et al. 1994; Yadav et al. 1995; Kamei et al. 2006a),
T. versicolor (Zeddel et al. 1993; Vyas et al. 1994; Cloete and Celliers 1999),
Lentinus edodes (Ruiz-Aguilar et al. 2002), P. ostreatus (Kubátová et al. 2001;
Čvančarová et al. 2012), Grifola frondosa (Seto et al. 1999), Coriolopsis polyzona
(Vyas et al. 1994; Novotný et al. 1997), Phlebia brevispora (Kamei et al. 2006b),
I. lacteus (Čvančarová et al. 2012), B. adusta (Beaudette et al. 1998; Čvančarová
et al. 2012), Pycnoporus cinnabarinus (Čvančarová et al. 2012), Phanerochaete
magnoliae (Čvančarová et al. 2012). Generally, all these studies confirmed that the
extent of degradation significantly decreases with increasing chlorine content.
Moreover, the mechanisms by which fungi degrade PCBs were widely investigated (Beaudette et al. 1998; Krčmář et al. 1999; Kamei et al. 2006a, 2006b; Takagi
et al. 2007; Čvančarová et al. 2012; Stella et al. 2017).
Nevertheless, few studies investigated the ability of WRFs to degrade PCBs in
actual contaminated soils (Borazjani et al. 2005; Federici et al. 2012; Stella et al.
2017; Siracusa et al. 2017). Borazjani et al. (2005) tested different treatments for the
remediation of soil contaminated by the technical PCB mixtures Aroclor 1242, 1248,
and 1260. The highest degradation extent for the higher chlorinated mixture 1260
was observed when kenaf (a lignocellulosic substrate) inoculated with the white-rot
fungus P. chrysosporium was mixed with soil (3% w/w). Another study demonstrated that 33.6% of Aroclor 1260 depletion and 23.2% of dechlorination was
reached in 60 days by a bioaugmentation approach based on the use of maize
stalk-immobilized fungus Lentinus tigrinus (Federici et al. 2012).
The PCB-degrading abilities of two white-rot fungi, namely P. ostreatus and
I. lacteus, were also assessed in long-term PCB-contaminated soils the contamination of which was mostly caused by the presence of Delor 103 PCB mixture (Stella
et al. 2017). Three soil samples, which differed in their PCB contents, were selected
for microcosm preparation: bulk soil, topsoil, and rhizosphere soil. The soils were
mixed with either P. ostreatus- or I. lacteus-colonized lignocellulosic substrate
(LS) for bioaugmentation treatments to reach a final soil:LS mass ratio of 5:1
(w/w) and incubated for 12 weeks. The greatest PCB depletion (50.5%) was
achieved in the P. ostreatus-augmented rhizosphere soil, whilst I. lacteus led to
the degradation of 30.3% of the original amount after 12 weeks of the incubation. On
the other hand, for the most contaminated soil (bulk soil), no significant decrease in
the PCB concentration was observed within the first 6 weeks of the incubation
regardless of the treatment employed. Moderate removals (18.5 and 19.3%) were
observed only after 12 weeks in P. ostreatus- and I. lacteus-augmented microcosms,
respectively.
22 Mycoremediation of Contaminated Soils
449