D. squalens, P. ostreatus, and Coprinus comatus) towards a historically
PAH-contaminated soil collected from a wood preservation plant (Covino et al.
2010a, b). L. tigrinus was significantly more efficient in PAH removal than I. lacteus
regardless of the inoculum carrier used (wheat straw, corn cobs, and commercial
pellets) (Covino et al. 2010a). Fluorene, phenanthrene, and anthracene were the most
degraded ones (degradation extent ranging from 75% to 91%), whereas chrysene
was the least degraded compound (percentages of removal ranging from 1 to 9%).
The lower degradation of chrysene was attributed to the higher hydrophobicity of
this hydrocarbon with respect to other PAHs, thus to its low bioavailability (available fraction of chrysene was only 41.1%). In the second study, P. ostreatus
immobilized on commercial pellets resulted to be the most effective fungal inoculant
being able to partially deplete even the most recalcitrant PAHs such as benzo[a]
pyrene and chrysene (Covino et al. 2010b).
The fungal bioaugmentation treatment of an aged creosote-contaminated soil was
also evaluated by Lladó et al. (2013). In this case, the degradation capabilities of two
strains of WRFs (T. versicolor and L. tigrinus) towards high-molecular-weight
polycyclic aromatic hydrocarbons (HMW-PAHs) were compared. The soil, collected after a 180-days-long biopiling treatment at pilot scale, contained mostly 4and 5-ring PAHs, the former ones being the most degraded in L. tigrinus microcosms
supplemented with Mn
2+ ions.
Concerning non-ligninolytic fungi, bioaugmented microcosms with SMS of the
basidiomycete Agaricus bisporus were set up at laboratory scale to treat a soil
contaminated by Pb and PAHs (García-Delgado et al. 2015). These microcosms
led to higher PAH removal and ecotoxicity reduction than their respective
biostimulated ones (soil mixed only with sterilized SMS). Moreover, the highest
PAH degradation (27% with respect to the initial concentration of 757 mg/kg) was
achieved in microcosms where A. bisporus was re-inoculated.
A fungal strain isolated from a contaminated soil (Mucor mucedo) was also tested
for its ability to degrade PAHs in two soils collected from a manufactured gas plant
(MGP) and from a wastewater-irrigated site (WIS) (Guo et al. 2016). Mucoraugmented microcosms led to a removal of PAHs of 72 and 62% in MGP and
WIS soils, respectively, after 30 days of incubation with the highest degradation
observed for the 3-ring PAHs.
In a recent research study, three fungal strains of Aspergillus spp., one of
Rhizomucor sp., one of Trichoderma sp., and eight bacterial strains were isolated
from heavy crude oil-contaminated soils and selected for the construction of two
consortia to use for the decontamination of a PAH-polluted soil (Zafra et al. 2017).
The first consortium (C1), constituted by the aforementioned fungal and bacterial
strains, was able to remove only low molecular weight PAHs, whereas the second
consortium C2 (C1 with the addition of two genetically modified strains of Aspergillus niger expressing LiP and MnP genes from P. chrysosporium) degraded also
the high-molecular-weight PAHs.
22 Mycoremediation of Contaminated Soils
453
PAH-contaminated soil collected from a wood preservation plant (Covino et al.
2010a, b). L. tigrinus was significantly more efficient in PAH removal than I. lacteus
regardless of the inoculum carrier used (wheat straw, corn cobs, and commercial
pellets) (Covino et al. 2010a). Fluorene, phenanthrene, and anthracene were the most
degraded ones (degradation extent ranging from 75% to 91%), whereas chrysene
was the least degraded compound (percentages of removal ranging from 1 to 9%).
The lower degradation of chrysene was attributed to the higher hydrophobicity of
this hydrocarbon with respect to other PAHs, thus to its low bioavailability (available fraction of chrysene was only 41.1%). In the second study, P. ostreatus
immobilized on commercial pellets resulted to be the most effective fungal inoculant
being able to partially deplete even the most recalcitrant PAHs such as benzo[a]
pyrene and chrysene (Covino et al. 2010b).
The fungal bioaugmentation treatment of an aged creosote-contaminated soil was
also evaluated by Lladó et al. (2013). In this case, the degradation capabilities of two
strains of WRFs (T. versicolor and L. tigrinus) towards high-molecular-weight
polycyclic aromatic hydrocarbons (HMW-PAHs) were compared. The soil, collected after a 180-days-long biopiling treatment at pilot scale, contained mostly 4and 5-ring PAHs, the former ones being the most degraded in L. tigrinus microcosms
supplemented with Mn
2+ ions.
Concerning non-ligninolytic fungi, bioaugmented microcosms with SMS of the
basidiomycete Agaricus bisporus were set up at laboratory scale to treat a soil
contaminated by Pb and PAHs (García-Delgado et al. 2015). These microcosms
led to higher PAH removal and ecotoxicity reduction than their respective
biostimulated ones (soil mixed only with sterilized SMS). Moreover, the highest
PAH degradation (27% with respect to the initial concentration of 757 mg/kg) was
achieved in microcosms where A. bisporus was re-inoculated.
A fungal strain isolated from a contaminated soil (Mucor mucedo) was also tested
for its ability to degrade PAHs in two soils collected from a manufactured gas plant
(MGP) and from a wastewater-irrigated site (WIS) (Guo et al. 2016). Mucoraugmented microcosms led to a removal of PAHs of 72 and 62% in MGP and
WIS soils, respectively, after 30 days of incubation with the highest degradation
observed for the 3-ring PAHs.
In a recent research study, three fungal strains of Aspergillus spp., one of
Rhizomucor sp., one of Trichoderma sp., and eight bacterial strains were isolated
from heavy crude oil-contaminated soils and selected for the construction of two
consortia to use for the decontamination of a PAH-polluted soil (Zafra et al. 2017).
The first consortium (C1), constituted by the aforementioned fungal and bacterial
strains, was able to remove only low molecular weight PAHs, whereas the second
consortium C2 (C1 with the addition of two genetically modified strains of Aspergillus niger expressing LiP and MnP genes from P. chrysosporium) degraded also
the high-molecular-weight PAHs.
22 Mycoremediation of Contaminated Soils
453