MYCOREMEDITATION-Dr.Kalonga,AE.
One of the major environmental problems facing the
world today is the contamination of soil, water and
air by toxic chemicals as a result of industrializa
tion and extensive use of pesticides in agriculture.
.
Incineration is currently the most effective and co
mmon remediation practice but is costly in terms of
money and energy used. A rapid cost effective and e
cologically responsible method of clean-up is
“bioremediation” which utilizes micro-organisms to
degrade toxic pollutants in an efficient economical
approach. Toxic chemicals are degraded to less harm
ful forms. Although, bioremediation by bacteria
agents has received attention of workers, the role
of fungi has been inadequately studied. The ability
of
fungi to transform a wide variety of hazardous chem
icals has aroused interest in using them for
bioremediation. Mushroom forming fungi (mostly basi
diomycetes), are amongst nature’s most powerful
decomposers, secreting strong extra cellular enzyme
s due to their aggressive growth and biomass
production. These enzymes include lignin peroxidase
s (LiP), manganese peroxidase (MnP) and laccase,
etc. Thus, carbon sources such as sawdust, straw an
d corn cob can be used to enhance degradation
rates by these organisms at polluted sites. White r
ot fungi have been used for biotransformation of
ot fungi have been used for biotransformation of
pesticides, degradation of petroleum hydrocarbons a
nd lignocellulolytic wastes in the pulp and paperindustry.
The main mechanism of biodegradation employed by this
group of fungi is the lignin degradation system of
enzymes. Extra-cellular lignin modifying enzymes
(LME’s) have very low substrates-specificity so they are
able to mineralize a wide range of highly recalcitrant
organopollutants that is structurally similar to lignin. The major
components of lignin degradation system include lignin-
peroxidase (LiP), manganese peroxidase (MnP), H2O2
producing enzymes and laccase,
although not all lignolytic fungi show the three types ofenzymatic activity.
It has been demonstrated that a lot of species
belonging to the group of white-rot fungi are ableto
degrade lignin, which is a naturally occurring polymer
.This capacity is assumed to resultfrom
the activities of extracellular oxidases and laccases. These enzymes are non-
specific; they oxidize a wide range of xenobiotics.
