116
Bioremediation for Sustainable Environmental Cleanup
Table 7.3. Remediation of pesticides by common algal/cyanobacterial strain.
Algal/
cyanobacterial
Strain
Pesticide
Mode of action
Remediation
(%)
Retention
time
References
Nostoc
Malathion
Biodegradation
91
52 d
Ibrahim et al. 2014
Coleofasciculus
Chlorpyrifos
Biodegradation
90
21 d
Vijayan et al. 2020
Fischerella
Methyl parathion
Bioadsorption
~ 80
5 d
Tiwari et al. 2017
Chlamydomonas
Trichlorfon
Biodegradation
100
10 d
Wan et al. 2020
Fluroxypyr
Bioaccumulation/
biodegradation
57
5 d
Zhang et al. 2011
Prometryne
Bioaccumulation/
biodegradation
30-40
4 d
Jin et al. 2012
Atrazine
Bioaccumulation
14-36
Kabra et al. 2014
Scenedesmus
Pyrimethanil
Biodegradation
10
4 d
Dosnon-Olette et al.
2010
Dimethomorph
Biodegradation
24
4 d
Dosnon-Olette et al.
2010
Isoproturon
Biodegradation
58
4 d
Dosnon-Olette et al.
2010
Chlorella
Simazine
Biodegradation
97
5 d
Hussein et al. 2017
Pendimethalin
Biosorption
88
5 d
Hussein et al. 2017
d – days
In the biosorption process, the liquid and solid phases contain the dissolved or suspended pesticides
to be absorbed. It could be defined as the attachment of potentially toxic pesticides to the surface
of the photosynthetic strain. Pesticides are biosorbed in a passive and metabolically independent
process that occurs faster than bioaccumulation (Verasoundarapandian et al. 2022). Strains
such as Chlorella and Fischerella have been reported to remediate > 80% of pesticides through
biosorption (Hussein et al. 2017, Tiwari et al. 2017). While bioaccumulation studies on fluroxypyr,
prometryne and atazarine, have shown that members of Chlorophyta are able to accumulate
pesticides during 4–5-d intervals but at a lower rate (< 60%) (Jin et al. 2012, Kabra et al. 2014,
Zhang et al. 2021). The bioaccumulation ability of organisms such as algae is determined by their
lipid content, which is influenced by their growth conditions and cell distribution (Sakurai et al.
2016). In addition to bioaccumulating pesticides, these photosynthetic organisms are also able to
transform and degrade pesticides into non-toxic or less toxic compounds. Pesticide degradation is
influenced by microorganism types, optimal environmental conditions and the metabolic activity of
various enzymes (hydrolase, phosphatase, phosphodiesterase, oxygenase, esterase, transferase and
oxidoreductases) (Verasoundarapandian et al. 2022). The probable biosorption, bioaccumulation
and biodegradation processes for the removal of pesticides in photosynthetic microorganisms are
shown in Figure 7.3.
Phycoremediation technology offers additional benefits such as minimized greenhouse
gas emissions from the environment and biomass reuse (Renuka et al. 2018, Reddy et al. 2021,
Renuka et al. 2021). Therefore, phycoremediation of pesticides can be a promising integrated and
sustainable approach for eco-friendly and efficient removal of pesticides from contaminated areas
with additional environmental benefits (Singh et al. 2020).