Application of real-time PCR to determination of combined effect of antibiotics on Bacteria, Methanogenic Archaea, Archaea in anaerobic sequencing batch reactors. (1st June 2015)

• Record Type: Journal Article
• Authors: Aydin, Sevcan; Ince, Bahar; Ince, Orhan
• Is Part Of: Water research. Volume 76(2015)
• Page Start: 88
• Page End: 98
• Publication Date: 2015-06-01
• Subjects: Real-time PCR -- Combined effects -- Antibiotics -- Anaerobic treatment -- Methanogenic Archaea -- Acetogens; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2015.02.043
• Languages: English
• ISSNs: 0043-1354

Abstract

Abstract: This study evaluated the long-term effects of erythromycin-tetracycline-sulfamethoxazole (ETS) and sulfamethoxazole-tetracycline (ST) antibiotic combinations on the microbial community and examined the ways in which these antimicrobials impact the performance of anaerobic reactors. Quantitative real-time PCR was used to determine the effect that different antibiotic combinations had on the total and active Bacteria, Archae and Methanogenic Archae. Three primer sets that targeted metabolic genes encoding formylterahydrofolate synthetase, methyl-coenzyme M reductase and acetyl-coA synthetase were also used to determine the inhibition level on the mRNA expression of the homoacetogens, methanogens and specifically acetoclastic methanogens, respectively. These microorganisms play a vital role in the anaerobic degradation of organic waste and targeting these gene expressions offers operators or someone at a treatment plant the potential to control and the improve the anaerobic system. The results of the investigation revealed that acetogens have a competitive advantage over Archaea in the presence of ETS and ST combinations. Although the efficiency with which methane production takes place and the quantification of microbial populations in both the ETS and ST reactors decreased as antibiotic concentrations increased, the ETS batch reactor performed better than the ST batch reactor. According to the expression of genes results, the syntrophic interaction of acetogens and methanogens is critical to the performance of the ETS and ST reactors. Failure to maintain the stability of these microorganisms resulted in a decrease in the performance and stability of the anaerobic reactors. Highlights: We examine triple and dual effects of antibiotics on anaerobic pathway throughout a year operation. qPCR analysis of functional genes offer the potential for control and the improvements on the anaerobic system. Antibiotic combinations have more dramatic effect on Methanogenic Archaea than total archaea combined. Quantifying the mcrA gene is essential for maintain efficient and stable in operation of the anaerobic process.