Bioremediation: A Sustainable Approach for Environmental Cleanup 9

Table 1.3. Pesticides degrading microorganisms.

Pesticides

Microorganism

References

Endosulfan

Micrococcus sp. strain, 2385

Pathak et al. 2016

DDT

Ochrobacterum sp.

Pan et al. 2017

Nitrophenol

Rhodoccus sp.

Sengupta et al. 2019

Cypermethrin chlordecone

Bacillus subtilis

Gangola et al. 2018

Citrobacter

Chaussonnerie et al. 2016

(Lindane) hexachloro-cyclohexane

Microbacterium

Zhang et al. 2020

Chloropyrifos, diazinon

Streptomyces sp.

Briceño et al. 2018

S- triazine (atrazine)

Arthrobacter sp. Strain Ak-YNIO

Sagarkar et al. 2016

Hexachloro-cyclohexane

Paenibacillus dendritiformis SJPS-4

Jaiswal et al. 2022

Glyphosate, 2-4D, Atrazine

Bradyrhizobium sp. BR 3901

Barroso et al. 2020

Endosulfan

Aspergillus trichoderma spp.

Gangola et al. 2015

Atrazine

Fusarium sp.

Esparza-Naranjo et al. 2021

Degrading enzymes are relatively more resistant to anomalous environmental circumstances

than microbial cells capable of producing such enzymes, and their degradable efficiency is

substantially higher than that of microorganisms, especially at low pesticide doses. As a result, using

degrading enzymes to detoxify the environment that has been contaminated by pesticides would be

a more effective method.

1.5.4 Bioremediation of Textile Dyes

Various industrial effluents, including those from textile, printing, pharmaceutical and other

industries, cause wastewater contamination (Uday et al. 2016). Dyes industries were established

during the same period of rapid industrialization and urbanization as other sectors. Many different

kinds of dyes are present in textile effluents. Based on their chemical makeup, dyes are divided

into several categories, such as Anthraquinone bases, metal complex dyes, di-azo and basic dyes.

These dyes might be cationic, anionic or neutral (Vikrant et al. 2018). According to Daneshvar et al.

(2007), artificial dyes, such as azo, xanthenes and anthraquinone dyes, are extremely toxic to living

things. When the dye forms compounds with other contaminants and deteriorates materials in the

environment, its toxicity increases. Additionally, these dyes can contribute to hereditary illnesses

that are incurable (Lellis et al. 2019).

Dyes can come from natural or synthetic sources or they can be generated via an inorganic

technique, in the wastewater produced by textile manufacturers (Varjani et al. 2021). Synthetic dyes

are inexpensive ingredients that come in large quantities, as well as being commonly used (Rossi

et al. 2017). Common dyes are anthraquinone dyes, that have polycondensed ring structures and

hydroxyl or amino functionalities. Different kinds of microorganisms used in the biodegradation of

textile dyes are given in Table 1.4.

Various enzymes are used in the decolorization of textile dyes, including formate dehydrogenase,

oxidases based on glyoxal and aryl-alcohol compounds and peroxidase (Chen et al. 2016, Sarkar

et al. 2017). Laccases are valuable enzymes in the decolorizing process because aromatic compounds

with azo and anthraquinone linkages are some of their substrates. Laccase is a multicooper oxidase

enzyme that may be found in a variety of microorganisms (e.g., microalgae, fungi and bacteria)

(Motamedi et al. 2021). A biodegradation pathway for Congo Red Dye utilizing azoreductase and

laccase was proposed by Lade et al. (2015). By breaking azo bonds in the presence of azoreductase,

the biodegradation of Congo Red Dye produces biphenyl-4, 4′-diamine and an unexplained

intermediate. As a result of this microbial degradation phase, the dye is decolored and aromatic

amines are formed as an end product. Furthermore, the presence of laccase causes the production