Azoreductase kinetics and gene expression in the synthetic dyes-degrading Pseudomonas

Abstract

Microorganisms have an effective capability to degrade synthetic dyestuff enzymatically. In this study, two 16S rRNA identified Pseudomonas aeruginosa bacterial isolates (ASU3 and ASU6) have been screened to enzymatically degrade both Disperse Blue 64 (DB64) and Acid Yellow 17 (AY17) which resembles 2 of the synthetic dyes that causes aquatic environmental pollution. The expression of the azoR1 gene has been detected in the strains, the degradation percentage of DB64 and AY17 by stain ASU6 was found to exceed the ASU3. This returned to the differences in the expression levels of azoR1 between the ASU6 and the ASU3 which was confirmed by RT-PCR. In addition, the specific activity (U/mg protein) of azoreductase in ASU6 was higher than ASU3 when MethylRed (MR), DB64 and AY17 were used as a substrate, separately. The azoreductase kinetics was studied to find the optimum condition for maintaining the stability of the enzyme. The degraded products separated by HPLC/MS were tested for their toxicity on two crop plants and they were nontoxic to the plants.

Decolorization mechanism, identification of an FMN‐dependent NADH‐azoreductase from a moderately halotolerant Staphylococcus sp. MEH038S, and toxicity assessment of biotransformed metabolites

“…Bacterial strains have a unique cytoplasmic azoreductase system that can act as a catalyst for the transmission of the electron from an electron donor (NADH) to the azo group of dyes. Thus, the existence of substrates like dyes leads to the induction of the azoR enzyme (Elfarash et al, 2017). AzoR breaks azo bonds by the transmission of four electrons in two steps.…”

“…Degradation metabolites of Acid Blue‐61 by filamentous fungi A. terreus had toxic effects on Lactuca sativa seeds (Almeida & Corso, 2019). Decolorization of azo dyes occurs with the breakage of chromophoric azo groups that can cause the production of colorless aromatic amine metabolites (Elfarash et al, 2017). These aromatic amines are resistant and poisonous which have detrimental impacts on animals and humans (Chen et al, 2018).…”

“…strain MEH038S. To date, azoreductase is identified from different microorganisms (Elfarash et al, 2017; Hua & Yu, 2019). However, no studies have been performed on the identification of the gene encoding azoreductase from a moderately halotolerant Staphylococcus .…”

Quantification of Naphthalene Dioxygenase (NahAC) and Catechol Dioxygenase (C23O) Catabolic Genes Produced by Phenanthrene-Degrading Pseudomonas fluorescens AH-40

“…and Achromobacter dentrificanse [ 7 , 10 , 28 ]. Pseudomonas sp is one of the most popular bacterial species that could be isolated from different contaminated sources [ 29 ]. In addition, Pseudomonas sp can degrade many types of pollutants like PAHs [ 11 , 23 ], Aliphatic hydrocarbons [ 30 ] and industrial dyes [ 29 ].…”

Kavak Ağacı Kabuğu Esaslı Sorbentlerin 25 Tam Faktöriyel Deney Tasarımı Kullanılarak Boyarmadde Gideriminde Değerlendirilmesi ve %Giderim Etkinliğinin İstatistiksel Analizi

“…2030 yılına kadar sürdürülebilir su yönetimi hedefine ulaşmak için her gün yaklaşık 600000 kişiye ekstra atık su arıtma tesisi gerekmektedir [5]. Çevreye yayılan en tehlikeli ve zehirli kirleticilerden biri olarak kabul edilen boyar maddeler kimyasal, su, ışık veya mikrobiyal işlemlere maruz bırakılsalar bile bozulmaya karşı direnç göstermektedir [6]. Endüstride sıklıkla kullanılan boyar maddelerin % 10-15'i boyama sürecinde atık sulara boşaltılmaktadır [7].…”