Department of Biology, Molecular Biology Section, Pamukkale University, 20160, Denizli, Turkey.
Folia Microbiol (Praha). 2024 Dec;69(6):1343-1353. doi: 10.1007/s12223-024-01176-x. Epub 2024 May 29.
Phthalic acid isomers are the monomers of phthalate molecules, also known as phthalic acid esters, widely employed in the plastics industry. This study aims to investigate the biodegradation of phthalic acid (PA) and terephthalic acid (TPA) by five industry-borne Comamonas testosteroni strains: 3APTOL, 3ABBK, 2B, 3A1, and C8. To assess the ability of C. testosteroni strains to biodegrade phthalic acid isomers in fermentation media, an analytical method was employed, consisting of high-performance liquid chromatography (HPLC) analyses. Subsequently, molecular screening of the genomic and plasmid DNA was conducted to identify the degradative genes responsible for the breakdown of these chemicals. The genes of interest, including ophA2, tphA2, tphA3, pmdA, and pmdB, were screened by real-time PCR. The five C. testosteroni strains effectively degraded 100% of 100 mg/L PA (p = 0.033) and TPA (p = 0.0114). Molecular analyses indicated that all C. testosteroni strains contained the pertinent genes at different levels within their genomes and plasmids, as reflected in the threshold cycle (Ct) values. Additionally, DNA temperature of melting (Tm) analyses uncovered minor differences between groups of genes in genomic and plasmid DNA. C. testosteroni strains could be excellent candidates for the removal of phthalic acid isomers from environmental systems.
邻苯二甲酸异构体是邻苯二甲酸酯分子的单体，也称为邻苯二甲酸酯，广泛应用于塑料工业。本研究旨在研究五株工业来源的丛毛单胞菌（Comamonas testosteroni）菌株 3APTOL、3ABBK、2B、3A1 和 C8 对邻苯二甲酸（PA）和对苯二甲酸（TPA）的生物降解。为了评估 C. testosteroni 菌株在发酵培养基中生物降解邻苯二甲酸异构体的能力，采用了高效液相色谱（HPLC）分析的分析方法。随后，对基因组和质粒 DNA 进行分子筛选，以鉴定负责这些化学品分解的降解基因。通过实时 PCR 筛选了感兴趣的基因，包括 ophA2、tphA2、tphA3、pmdA 和 pmdB。这五株丛毛单胞菌有效地降解了 100mg/L 的 100% PA（p=0.033）和 TPA（p=0.0114）。分子分析表明，所有 C. testosteroni 菌株在其基因组和质粒 DNA 中以不同水平包含相关基因，这反映在阈值循环（Ct）值中。此外，DNA 熔点（Tm）分析揭示了基因组和质粒 DNA 中基因组之间的微小差异。丛毛单胞菌菌株可能是从环境系统中去除邻苯二甲酸异构体的优秀候选者。
