protoplasm fusion of endophyteMucorsp. in rape roots contaminated the soil with
Pb and Cd.
Although heavy metals are toxic to plants, it has been demonstrated that many
plants are metal tolerant and some of them are metal hyper accumulators (Rosa
et al. 2004 ; Li et al. 2012 ). Many metal resistant endophytes were isolated from
hyperaccumulating plants. These fungi belonged to various taxa include
Microsphaeropsis,Mucor, Phoma, Alternaria, Pyronellaea, Steganosporiumand
Aspergillus. Soleimani et al. ( 2010 ) demonstrated that endophytic fungi were
helpful in phytoremediation of aged petroleum contaminated soil and that these
fungi improved host plants roots and shoot biomass and created higher levels of
water soluble phenols and dehydrogenase activity in the soilTCE, Naphthalene,
BTEX, catechol and phenol could be degraded by endophytes which decreased the
contaminant phytotoxicity and improved plant growth (Weyens et al. 2010 ;Ho
et al. 2009; Li et al. 2012 ).
3.5 Endophytic Fungi in Bio Degradation of Pollutants
Fungi are known to utilize a wide range of organic compounds for nutrition and
energy generation through extracellular enzymes. These organic compounds
include cellulose, pectin, lignin, lignocelluloses, chitin and starch and anthro-
pogenic substances such as hydrocarbons, pesticides and other xenobiotics. The
white rot fungi likePhaenerochate chrysosporiumcan degrade several xenobiotics
such as aromatic hydrocarbons, chlorinated organics, poly chlorinated biphenyls,
nitrogen containing aromatics and many other pesticides, dyes and xenobiotics
(Gadd 2007 ; Harvey and Thursten 2009 ).
The use of fungi to clean up environmental pollutants has gained the momentum
in past few years, however most studies have focussed on white rot fungi
(Marco-Urrea et al. 2008 ; Nikiforova et al. 2009 ) and the use of endophytic fungi
might be a novel approach and important source for degradation of toxic pollutants
which includes hydrocarbons, polychlorinated biphenyls (PCBs), polyaromatic
hydrocarbons (PAHs), radionuclides and metals.
Fungi are known to degrade PAHs in surface of soil. These fungi produce
extracellular enzymes with lower substrate specify which enable degrade aromatic
compounds including PAHs (Leonardi et al. 2007 ; Farnet et al. 2009 ). In a study,
manganese peroxidase was found to be the dominant ligninolytic enzyme in the
degradation PAH (Tian et al. 2007 ; Dai et al. 2007 ). Researchers found that
endophytic fungi might be a novel and important resource for the degradation of
polycyclic aromatic hydrocarbons (PAHs). An endophyte fungal strain
Ceratobasidium stevensiiisolated from the plant ofEuphorbiaceaewas found to
metabolize phenanthrene effectively (Dai et al. 2010 ). Tian et al. ( 2007 ) demon-
strated the degradation of phenanthrene by endophyticPhomopsissp., with rice
plant. In a study, endophyticXylariaceaestrains isolated from healthy tropical
native plants of Thailand found to be the producers of ligninolytic enzymes
54 Y.L. Krishnamurthy and B.S. Naik