Chronic impact of tetracycline on the biodegradation of an organic substrate mixture under anaerobic conditions

Abstract

24The study evaluates the chronic impact of the antibiotic tetracycline on the biodegradation of 25 organic substrate under anaerobic conditions. The experiments involved an anaerobic 26 M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT2 sequencing batch reactor fed with a synthetic substrate mixture including glucose, starch and 1 volatile fatty acids, and operated in a sequence of different phases with gradually increasing 2 tetracycline doses of 1.65 -8.5 mg/L, for more than five months. Tetracycline exerted a 3 terminal/lethal effect at 8.5 mg/L on the microbial community under anaerobic conditions, 4 which caused the inhibition of substrate/COD utilization and biogas generation and leading to 5 a total collapse of the reactor. The microbial activity could not be recovered and re-started 6 within a period of more than 10 days, even after stopping tetracycline dosing. At lower doses, 7 substrate utilization was not affected but a reduction of 10-20% was observed in the 8 biogas/methane generation, suggesting that substrate utilization of tetracycline to the 9 biomass was limiting their bioavailability. During the experiments, tetracycline was partially 10 removed either through biodegradation or conversion into its by-products. The adverse long-11 term impact was quite variable for fermenting heterotrophic and methanogenic fractions of 12 the microbial community based on changes inflicted on the composition of remaining/residual 13 organic substrate. 14 15 16

Elimination patterns of worldwide used sulfonamides and tetracyclines during anaerobic fermentation

“…Tetracyclines are reported to show a strong sorption to biosolids such as soil or activated sludge (Hamscher et al, 2002;Prado et al, 2009). In one study using anaerobic conditions, only a minor sorption to the digester sludge was reported (Cetecioglu et al, 2013). As already discussed for sulfadiazine (see Section 3.2.2.…”

“…manure, activated sludge, biogas plant fermenter content), the initial compound concentration, or the duration of the experiment. In some cases no influence was found, whereas other studies revealed a decrease of the biogas and/or methane yield (Álvarez et al, 2010;Bauer et al, 2014;Cetecioglu et al, 2013;Lallai et al, 2002;Massé et al, 2000;Mitchell et al, 2013;Mohring et al, 2009;Sara et al, 2013).…”

“…Studies have shown the elimination of selected veterinary antibiotics during the anaerobic fermentation (Álvarez et al, 2010;Cetecioglu et al, 2013;Mitchell et al, 2013;Mohring et al, 2009;Riemenschneider et al, 2014). Thus, the process in biogas plants is discussed as potential sink for veterinary antibiotics.…”

Biodegradation and reversible inhibitory impact of sulfamethoxazole on the utilization of volatile fatty acids during anaerobic treatment of pharmaceutical industry wastewater

“…In contrast, the removal and biodegradability of SMX in anaerobic systems has not been widely studied. There are few studies regarding the anaerobic biodegradability characteristics of SMX in the literature (Gartiser et al, 2007;Cetecioglu, et al, 2013;Aydin et al, 2015;Martín et al, 2015). Gartiser et al (2007) assessed the biodegradability of the selected antibiotics.…”

Hydrothermal synthesis of novel flower-like BiVO 4 /Bi 2 Ti 2 O 7 with superior photocatalytic activity toward tetracycline removal

“…However, many antibiotics can be easily entered into the environment because of the poor absorption, low metabolism, abuse and overuse. Antibiotics in environment could cause lots of direct toxicities and potential risks (the effects include the development of super bacteria, direct or indirect toxicity to microorganism and possible risks to human beings) [1][2][3][4].…”