2.9.5 Development of Transgenic Plants with Enhanced Pesticide Degradation . . . . . . 59
2.10 Future Perspectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
2.11 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Abstract Various pesticides including organochlorines, organophosphates, carbamate, pyrethroids, chloronicotinyl etc., are used in agriculture for protection against
plant diseases and insects. Only a fraction of the applied pesticides is utilized in
killing of target pests and the leftover residual pesticides either remains associated
with cereal grains, vegetables, and fruits or may cause environmental pollution. In
addition to the traditional physical and chemical degradation methods, the microbial
degradation method is commonly more efficient and low-cost method used for
pesticide degradation. Microorganisms have been characterized which have the
capability to degrade residual pesticides. The microbes that demolish these pesticides use the pesticides as nutrients and break them down into tiny nontoxic
molecules. Pesticide degrading microbes belong to different microbial groups, i.e.,
bacteria, fungi, actinomycetes, and algae. Bacteria possessing pesticide degradation
capability include Pseudomonas spp., Bacillus spp., Burkholderia, Klebsiella spp.,
Streptomyces, etc. and the fungi include Trichoderma spp., Aspergillus spp.,
Phanerochaete chrysosporium, white rot fungi, etc., whereas algae include
Chlamydomonas and marine Chlorella. Major reactions in pesticide destruction
include mineralization and co-metabolism. Pesticide degradation is influenced by
many factors such as type of pesticide, type of microorganism, temperature, humidity, and acidity in the environment. Plasmid-located genes usually encode many
enzymes and degrade a large number of pesticides. Microorganisms may acquire
pesticide-degradation capabilities in soil through horizontal gene transfer from
degradative plasmids, by modification of substrate specificity, or through altered
regulation of preexisting enzymes. With the progress of molecular biology, the
genetically engineered rhizobacteria may be built to enhance the bioremediation of
pollutants and pesticides. Such recombinant microbial populations may be of
immense value in bioremediation of diverse pesticides from the surroundings.
Keywords Pesticides · Microbial degradation · Mineralization · Co-metabolism ·
Genetically engineered rhizobacteria
2.1 Introduction
Currently, various pesticides are extensively applied in agriculture to target pests,
weeds, and pathogens to protect crops in order to obtain high biomass and yield
productivity (Cycoń et al. 2017; Sindhu et al. 2018). In developing countries,
24
A. Sehrawat et al.
2.10 Future Perspectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
2.11 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Abstract Various pesticides including organochlorines, organophosphates, carbamate, pyrethroids, chloronicotinyl etc., are used in agriculture for protection against
plant diseases and insects. Only a fraction of the applied pesticides is utilized in
killing of target pests and the leftover residual pesticides either remains associated
with cereal grains, vegetables, and fruits or may cause environmental pollution. In
addition to the traditional physical and chemical degradation methods, the microbial
degradation method is commonly more efficient and low-cost method used for
pesticide degradation. Microorganisms have been characterized which have the
capability to degrade residual pesticides. The microbes that demolish these pesticides use the pesticides as nutrients and break them down into tiny nontoxic
molecules. Pesticide degrading microbes belong to different microbial groups, i.e.,
bacteria, fungi, actinomycetes, and algae. Bacteria possessing pesticide degradation
capability include Pseudomonas spp., Bacillus spp., Burkholderia, Klebsiella spp.,
Streptomyces, etc. and the fungi include Trichoderma spp., Aspergillus spp.,
Phanerochaete chrysosporium, white rot fungi, etc., whereas algae include
Chlamydomonas and marine Chlorella. Major reactions in pesticide destruction
include mineralization and co-metabolism. Pesticide degradation is influenced by
many factors such as type of pesticide, type of microorganism, temperature, humidity, and acidity in the environment. Plasmid-located genes usually encode many
enzymes and degrade a large number of pesticides. Microorganisms may acquire
pesticide-degradation capabilities in soil through horizontal gene transfer from
degradative plasmids, by modification of substrate specificity, or through altered
regulation of preexisting enzymes. With the progress of molecular biology, the
genetically engineered rhizobacteria may be built to enhance the bioremediation of
pollutants and pesticides. Such recombinant microbial populations may be of
immense value in bioremediation of diverse pesticides from the surroundings.
Keywords Pesticides · Microbial degradation · Mineralization · Co-metabolism ·
Genetically engineered rhizobacteria
2.1 Introduction
Currently, various pesticides are extensively applied in agriculture to target pests,
weeds, and pathogens to protect crops in order to obtain high biomass and yield
productivity (Cycoń et al. 2017; Sindhu et al. 2018). In developing countries,
24
A. Sehrawat et al.