pyrene

5

252.3

0.0023

Animal carcinogenicity

and eye infection

h]

e

5

278.4

0.0005

Carcinogenicity and

toxicity to aquatic life

i]peryl

6

276.3

0.00026

Toxicity to aquatic life,

lung and skin

2,3-

e

6

276.3

0.062

Carcinogenicity, nausea,

emesis and diarrhea

a]pyrene

5

252.3

0.0023

Animal carcinogenicity

and eye infection

[a,h]

ene

5

278.4

0.0005

Carcinogenicity and

toxicity to aquatic life

ghi]peryl

6

276.3

0.00026

Toxicity to aquatic life,

lung and skin

1,2,3-

ene

6

276.3

0.062

Carcinogenicity, nausea,

emesis and diarrhea

pyrene

5

252.3

0.0023

Animal carcinogenicity

and eye infection

h]

e

5

278.4

0.0005

Carcinogenicity and

toxicity to aquatic life

i]peryl

6

276.3

0.00026

Toxicity to aquatic life,

lung and skin

2,3-

e

6

276.3

0.062

Carcinogenicity, nausea,

emesis and diarrhea

Fungal Strategies for the Remediation of Polycyclic Aromatic Hydrocarbons 91

...Table 6.1 contd.

PAHs

No. of

Rings

Molecular

weight (g/mol)

Solubility

(mg/L)

Health risk

Structure

Dibenz[a,h]

anthracene

5

278.4

0.0005

Carcinogenicity and toxicity

to aquatic life

Benzo[ghi]

perylene

6

276.3

0.00026

Toxicity to aquatic life, lung

and skin

Indeno[1,2,3-cd]

pyrene

6

276.3

0.062

Carcinogenicity, nausea,

emesis and diarrhea

viz, biosorption used dead or alive microbial organic matter, bioaccumulation assisted by microbes,

biostimulation is ameliorating on-site microbial community, phytoremediation associated with plants,

bioaugmentation is the unnatural incorporation of microbial communities and rhizoremediation is

the interaction between plants and microbes. Among the bioremediation practices, microbes (algae,

fungi, bacteria) mediated remediation is the most effective in PAHs mineralization and numerous

documentations have reported more than 100 genera and 200 species of microorganisms. Where,

fungi are the most predominant group with 103 genera among the other microbial representatives,

i.e., bacteria (79 genera), algae (19 genera) and cyanobacteria (9 genera) documented from a

different environment and responsible for effective PAHs degradation (Premnath et al. 2021).

Fungi and bacteria utilize versatile strategies for remediating PAHs in contaminated soil. The first

stage of the bacterial PAHs degradation mechanism includes oxidation as well as hydroxylation of

PAHs. The detoxification operation is carried out as the initial stage in fungal PAHs mineralization.

Individually, fungal members like Aspergillus sp., Fusarium oxysporum and Trichocladium

canadense can also mineralize LMW-PAHs. However, in contrast to the LMW-PAHs, HMW-PAHs,

i.e., pyrene (PYR) and phenanthrene (PHE) can be efficiently mineralized by the Penicillium sp.,

A. terreus and Verticillium sp. (Biswas et al. 2015). Moreover, as a consortium of bacteria and

fungi, rather than individuals, proficiently enhance the rate of PAH degradation (Winquist et al.

2014, Li and Li 2008). On the other hand, fungal consortia of A. flavus, A. fumigatus, A. nomius,

Trichoderma asperellum and Rhizomucor variabilis can also escalate the remediation of Benzo(a)

pyrene [B(a)p], PYR and PHE (Tripathi et al. 2017). Universally fungal agents are equipped with

several remediating strategies like enzymatic activities, the production of biosurfactants and the

utilization of rhizospheric and endophytic fungal communities.

6.3.1 Enzymatic Activity

The notable evidence of fungal bioremediation is the synthesis of a vast number of biochemically active

biomolecules, primarily extracellular enzymes, i.e., Laccase, Cytochrome P450 monooxygenase

(CYP450), Lignin Peroxidase (LiP), Dioxygenase, Manganese peroxidase (MnP), Versatile

Peroxidase (VP), and Dye-decolorizing peroxidases, etc., by fungi. Primarily, there are two fungal

phenomenal bioremediation-oriented mechanisms, i.e., lignin catabolism-dependent mechanism

(ligninolytic fungi) and CYP450 system-dependent system (non-ligninolytic fungi) (Srivastava