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Abstract Pesticides have emerged as an integral tool of the farming activities and
are used extensively to meet the increasing demand for food and feed. About 99%
of the applied pesticides get accumulated in the nontarget organisms and environment. S-triazine herbicides have been classified as possible human carcinogens. Of
these, atrazine was mostly used as it increases yield up to 50% based on crop and
the most studied for toxicity and degradation. These pesticides are slowly degraded,
and persistence leads to accumulation in soil or migrate to water bodies posing a
severe threat to human and environment. Atrazine and its metabolites are frequently
detected in surface water and ground water at concentrations exceeding the safety
levels. We reviewed the biodegradation of s-triazine herbicides by microorganism,
plants, and their degradation pathways. It was noted that atrazine degrading genes
are widely distributed among the bacteria, but most of the bacterial strains do not
contain all the genes required for atrazine mineralisation. Atrazine mineralisation
appears to be more common in soils by microbial consortia than individual species.
Certain bacteria including Arthrobacter sp. SC-JAK2 can degrade atrazine of above
1 g L
−1
concentration which is far above the reported atrazine contaminant concentration in soil and water. Several reports concluded that excellent atrazine degraders
in laboratory media, fail to do that in the complex natural environmental conditions
that are suboptimal for growth or repress the synthesis of enzymes involved in the
degradation pathway. Biostimulation and bioaugmentation studies showed rapid
biodegradation of atrazine in contaminated sites. Major advances in the biodegradation of s-triazine-contaminated sites include the usage of genetically modified or
engineered microorganisms, enzymatic bioremediation, and use of nanomaterials.
With the help of advanced molecular and physiological approaches, it is possible to
monitor the bioremediation and microbial community development in the atrazinecontaminated soil.
Keywords Atrazine · S-Triazine · Bioaugmentation · Biodegradation ·
Bioremediation · Biostimulation · Contaminant · Environment · Herbicides ·
Pesticides
2.1 Introduction
To meet the global requirement of food and fuel to some extent, pesticides are being
used extensively in agriculture. Less than 0.1% of the applied pesticides reach the
target organism, and the remainder gets deposited in soil and nontarget organisms
or move into nearby water streams and lakes by leaching and agricultural runoff
(Pimentel and Levitan 1986). These pesticides cause contamination of the environment and adversely affect the nontarget organisms and plants because of their persistence in the soil and water bodies. The persistence of pesticides in the soil and
water mainly depend on chemical stability, solubility in water, soil physicochemical
properties, climatic conditions, soil microbial activity, and leaching. Pollution of
soil and water with pesticides and their toxic metabolites have become a major
K. Rajendran et al.
Abstract Pesticides have emerged as an integral tool of the farming activities and
are used extensively to meet the increasing demand for food and feed. About 99%
of the applied pesticides get accumulated in the nontarget organisms and environment. S-triazine herbicides have been classified as possible human carcinogens. Of
these, atrazine was mostly used as it increases yield up to 50% based on crop and
the most studied for toxicity and degradation. These pesticides are slowly degraded,
and persistence leads to accumulation in soil or migrate to water bodies posing a
severe threat to human and environment. Atrazine and its metabolites are frequently
detected in surface water and ground water at concentrations exceeding the safety
levels. We reviewed the biodegradation of s-triazine herbicides by microorganism,
plants, and their degradation pathways. It was noted that atrazine degrading genes
are widely distributed among the bacteria, but most of the bacterial strains do not
contain all the genes required for atrazine mineralisation. Atrazine mineralisation
appears to be more common in soils by microbial consortia than individual species.
Certain bacteria including Arthrobacter sp. SC-JAK2 can degrade atrazine of above
1 g L
−1
concentration which is far above the reported atrazine contaminant concentration in soil and water. Several reports concluded that excellent atrazine degraders
in laboratory media, fail to do that in the complex natural environmental conditions
that are suboptimal for growth or repress the synthesis of enzymes involved in the
degradation pathway. Biostimulation and bioaugmentation studies showed rapid
biodegradation of atrazine in contaminated sites. Major advances in the biodegradation of s-triazine-contaminated sites include the usage of genetically modified or
engineered microorganisms, enzymatic bioremediation, and use of nanomaterials.
With the help of advanced molecular and physiological approaches, it is possible to
monitor the bioremediation and microbial community development in the atrazinecontaminated soil.
Keywords Atrazine · S-Triazine · Bioaugmentation · Biodegradation ·
Bioremediation · Biostimulation · Contaminant · Environment · Herbicides ·
Pesticides
2.1 Introduction
To meet the global requirement of food and fuel to some extent, pesticides are being
used extensively in agriculture. Less than 0.1% of the applied pesticides reach the
target organism, and the remainder gets deposited in soil and nontarget organisms
or move into nearby water streams and lakes by leaching and agricultural runoff
(Pimentel and Levitan 1986). These pesticides cause contamination of the environment and adversely affect the nontarget organisms and plants because of their persistence in the soil and water bodies. The persistence of pesticides in the soil and
water mainly depend on chemical stability, solubility in water, soil physicochemical
properties, climatic conditions, soil microbial activity, and leaching. Pollution of
soil and water with pesticides and their toxic metabolites have become a major
K. Rajendran et al.