48
annually by corn and sugarcane industries, respectively, in the USA due to elimination of atrazine (US-EPA 2006). Furthermore, there will be much more loss when
all the atrazine-dependent crops are included. Postemergence application of other
herbicides involves several risk including (i) crop injury as it is applied directly to
the emerged crop and weeds, (ii) greater competition between crop and weeds until
herbicide application, and (iii) fewer or lack of emergency remedies for weed control if the application of herbicide is missed due to the bad weather or other factors.
Physical and chemical methods have not been effective in detoxifying the herbicides under field conditions. Biological methods are the most practical. Research on
phytoremediation for s-triazine-contaminated soil is limited. Microorganisms have
inherent ability to degrade triazine pesticides by utilising them as carbon and nitrogen source. 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. In these cases, enzymatic bioremediation is the excellent solution
available now. Since these herbicides are often used in combination with other pesticides, the remediation approaches must able to cope up and degrade or remove
these multi-pesticides. The limiting factor in atrazine biodegradation is the lack of
efficient atrazine-mineralising microorganisms that can cleave the triazine ring.
Much research has to be focussed on biostimulation, bioaugmentaion, and developing recombinant strains to cope up these conditions. With the help of advanced
molecular and physiological approaches, such as fluorescent in situ hybridization,
denaturing- and temperature-gradient gel electrophoresis and phospholipid fatty
acid analysis, and community-level physiological profiling, it is possible to monitor
the bioremediation and microbial community development in the atrazinecontaminated soil. The degradative potential of atrazine compromised sites can be
established using the primers for the atzABC enzymes.
Acknowledgements Dr. Kumar extend heartfelt thanks to Prof. Alisa S. Vangnai, Prof. Jittra
Piapukiew, and Graduate School, Chulalongkorn University, Bangkok, for their support. Authors
thank the authorities of Alagappa University for sponsoring Postdoctoral fellowship under RUSA
2.0. The authors are thankful for the RUSA Scheme Phase 2.0 grant [F-24-51/2014–U, Policy
(TNMulti-Gen), Department of Education, Govt. of India. Dt.09.10.2018].
References
Abbas HH, Elbashir AA, Aboul-Enein HY (2015) Chromatographic methods for analysis of
triazine herbicides. Crit Rev Anal Chem 45(3):226–240. https://doi.org/10.1080/1040834
7.2014.927731
Addorisio V, Pirozzi D, Esposito S, Sannino F (2011) Decontamination of waters polluted with
simazine by sorption on mesoporous metal oxides. J Hazard Mater 196:242–247. https://doi.
org/10.1016/j.jhazmat.2011.09.022
Alekseeva T, Prevot V, Sancelme M, Forano C, Besse-Hoggan P (2011) Enhancing atrazine biodegradation by Pseudomonas sp. strain ADP adsorption to Layered Double Hydroxide bionanocomposites. J Hazard Mater 191(1–3):126–135. https://doi.org/10.1016/j.jhazmat.2011.04.050
K. Rajendran et al.
annually by corn and sugarcane industries, respectively, in the USA due to elimination of atrazine (US-EPA 2006). Furthermore, there will be much more loss when
all the atrazine-dependent crops are included. Postemergence application of other
herbicides involves several risk including (i) crop injury as it is applied directly to
the emerged crop and weeds, (ii) greater competition between crop and weeds until
herbicide application, and (iii) fewer or lack of emergency remedies for weed control if the application of herbicide is missed due to the bad weather or other factors.
Physical and chemical methods have not been effective in detoxifying the herbicides under field conditions. Biological methods are the most practical. Research on
phytoremediation for s-triazine-contaminated soil is limited. Microorganisms have
inherent ability to degrade triazine pesticides by utilising them as carbon and nitrogen source. 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. In these cases, enzymatic bioremediation is the excellent solution
available now. Since these herbicides are often used in combination with other pesticides, the remediation approaches must able to cope up and degrade or remove
these multi-pesticides. The limiting factor in atrazine biodegradation is the lack of
efficient atrazine-mineralising microorganisms that can cleave the triazine ring.
Much research has to be focussed on biostimulation, bioaugmentaion, and developing recombinant strains to cope up these conditions. With the help of advanced
molecular and physiological approaches, such as fluorescent in situ hybridization,
denaturing- and temperature-gradient gel electrophoresis and phospholipid fatty
acid analysis, and community-level physiological profiling, it is possible to monitor
the bioremediation and microbial community development in the atrazinecontaminated soil. The degradative potential of atrazine compromised sites can be
established using the primers for the atzABC enzymes.
Acknowledgements Dr. Kumar extend heartfelt thanks to Prof. Alisa S. Vangnai, Prof. Jittra
Piapukiew, and Graduate School, Chulalongkorn University, Bangkok, for their support. Authors
thank the authorities of Alagappa University for sponsoring Postdoctoral fellowship under RUSA
2.0. The authors are thankful for the RUSA Scheme Phase 2.0 grant [F-24-51/2014–U, Policy
(TNMulti-Gen), Department of Education, Govt. of India. Dt.09.10.2018].
References
Abbas HH, Elbashir AA, Aboul-Enein HY (2015) Chromatographic methods for analysis of
triazine herbicides. Crit Rev Anal Chem 45(3):226–240. https://doi.org/10.1080/1040834
7.2014.927731
Addorisio V, Pirozzi D, Esposito S, Sannino F (2011) Decontamination of waters polluted with
simazine by sorption on mesoporous metal oxides. J Hazard Mater 196:242–247. https://doi.
org/10.1016/j.jhazmat.2011.09.022
Alekseeva T, Prevot V, Sancelme M, Forano C, Besse-Hoggan P (2011) Enhancing atrazine biodegradation by Pseudomonas sp. strain ADP adsorption to Layered Double Hydroxide bionanocomposites. J Hazard Mater 191(1–3):126–135. https://doi.org/10.1016/j.jhazmat.2011.04.050
K. Rajendran et al.