EFFICIENT DEGRADATION OF p-TOLUIC ACID BY STRAIN 3a2 AND DETERMINATION OF RING HYDROXYLATING DIOXYGENASE GENES


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Aksu D. , Diallo M. M. , Özdemir G.

4. ÇUKUROVA Uluslararası Bilimsel Araştırmalar Kongresi, Adana, Türkiye, 21 - 23 Şubat 2020, ss.153-154

  • Basıldığı Şehir: Adana
  • Basıldığı Ülke: Türkiye
  • Sayfa Sayıları: ss.153-154

Özet

ABSTRACT Purified terephthalic acid (PTA) is used in the production of materials such as plastics, textile fibers, paints, adhesives, which are frequently used in daily life. Para-Toluic acid (pTol) which is one of the raw material of PTA chemical is transmitted to wastewater during production. Since this chemical is harmful to living organisms, it needs to be treated. Biological treatment is the most popular treatment method at recent times. In this treatment, where most bacteria are used, harmful chemicals can be converted to carbon dioxide and water or less harmful chemicals. In particular, the study of catabolic genes involved in the biodegradation of harmful chemicals is very popular today. Aromatic hydroxylating dioxygenases are involved in aerobic catabolism of a wide range of aromatic compounds and plays a critical role in the carbon cycle. In our study, 3a2 isolate (Comamonas testosteroni) isplated from petrochemical wastewater was used. The degradation efficiency of 3a2 isolate in flasks containing different concentrations of pTol was evaluated. Biodegradation studies were performed by HPLC (High Performance Liquid Chromatography) at intervals of 24 hours. In addition, pTol degradation activity in different nitrogen sources such as yeast extract, peptone, urea, NaNO₃, and NH₄NO was investigated. After all these studies, the genes encoding the enzymes with the dominant catalytic activity of the bacteria were determined using specific primers to the target genes thought to be responsible for the degrading of the bacteria. In addition, genomic DNA and plasmid DNA isolations were made to determine the presence of these genes in bacteria and whether they were genomic or plasmid-derived. As a result of the study, it was determined that 3a2 isolates break down pTol chemical within 24 hours even at 1000 mg/L pTol concentration and the most effective nitrogen source in the degradation is yeast. Toluate dioxygenase (TADO), terephthalate 1,2 dioxygenase (TPADO) and phthalate 4,5 dioxygenase (PDO) genes were detected in the identification of genes. Keywords: aromatic dehydrogenase genes, biodegradation, para-toluic acid, Comamonas testosteroni

Acknowledgement: We wish to thank Ege University Scientific Research Projects Coordinator (FKB-2019-20395) for the financial support of this study. We also thank Ege University, Application, and Research Center for Testing and Analysis for their kind supports.