Alterations in total microbial activity and nitrification rates in soil due to amoxicillin‐spiked pig manure

Abstract

Most veterinary drugs enter the environment via manure application. However, ecotoxic effects of antibiotics are varying as a function of their physicochemical characteristics and for most antibiotics it is still unclear how these substances interact with soil biota. It was the aim of the present study to investigate effects of manure containing different concentrations of the antibiotic amoxicillin (AMX) on microbial‐community function in two different soils over an incubation time of 18 d. Therefore, soil respiration, potential nitrification, and the products of N turnover were measured. We could show that CaCl2‐extractable amounts of AMX in soil are low, even shortly after the application of high doses together with manure. Thus, not surprisingly basal respiration in soil was not influenced by the addition of the antibiotic with manure. In contrast, mainly shortly after manure addition the kinetic of substrate‐induced respiration was clearly shifted by the treatments depending on the presence of AMX in the manure. Potential nitrification rates in the two different soils were not significantly affected when data were related to the overall incubation time by the application of AMX to the manure. However, shortly after the addition of the manure containing AMX, a tendency to lower turnover rates was visible compared to the application of pure manure.

Do antibiotics have environmental side-effects? Impact of synthetic antibiotics on biogeochemical processes

“…The non-nitrogen-related studies involved sulfatereduction (Hansen et al 1992;Ingvorsen et al 2003;Liu et al 2014), pyrene degradation (Näslund et al 2008), iron reduction (Thiele-Bruhn and Beck 2005; Toth et al 2011), arsenic oxidation and reduction (Yamamura et al 2014), methanogenesis (Conkle and White 2012;Fountoulakis et al 2004;Liu et al 2014), and acetate biodegradation kinetics (Wunder et al 2013). We only found a few studies that examined the effect of antibiotics on several biogeochemical processes (Conkle and White 2012;Kotzerke et al 2008;Kotzerke et al 2011;Liu et al 2014;Rosendahl et al 2012;Toth et al 2011). …”

“…Across studies, the fate of the antibiotic substance during the experiment was often unconsidered, and only 40 % of the studies quantified the antibiotic concentration in the experimental medium to determine the effect on a certain process (Ahmad et al 2014;Campos et al 2001;Hansen et al 1992;Hou et al 2015;Kotzerke et al 2008;Kotzerke et al 2011;Liu et al 2014;Rico et al 2014 Effective concentration Effective concentration Rosendahl et al 2012;Thiele-Bruhn and Beck 2005;Yan et al 2013). Regardless the antibiotic family, these studies revealed considerable loss of antibiotics over the experiment.…”

“…Bacterial biofilms, made up of an aggregation of microbes of different species surrounded by extracellular polymers, are more tolerant than planktonic bacteria because polymers are resistant to penetration of toxic compounds (Campos et al 2001;Stewart 2002). Furthermore, the more tolerant bacteria in the biofilm benefit from the exposure and become the dominant members of the community (Knapp et al 2008), or tolerant bacteria may develop on the dead remains of the biofilm (Kotzerke et al 2011;Demoling et al 2009;Kleineidam et al 2010;Reichel et al 2013;Yergeau et al 2012).…”

Root colonization and effect of biocontrol fungus Paecilomyces lilacinus on composition of ammonia-oxidizing bacteria, ammonia-oxidizing archaea and fungal populations of tomato rhizosphere

“…The decrease in AOB and AOA abundance could be due to the inoculation of P. lilacinus, which occupied some of rhizosphere space and increased the depletion of ammonium and other nutrients (Qiu et al 2014). Bioactive compounds can inhibit soil microbial activity and N-transformations Kotzerke et al 2011). Fungi belonging to the genus Paecilomyces can synthesize a wide range of bioactive compounds, including pyridone alkaloid inhibiting acetylcholinesterase activity (Teles and Takahashi 2013) and cyclohexadepsipeptide showed cytotoxicity to two cancer cell lines (Isaka et al 2007).…”

Antibiotics and antibiotic resistant bacteria in wastewater: Impact on environment, soil microbial activity and human health

“…As novel persistent pollutants, antibiotics were included in limitations issued by the Food and Agriculture Organization (FAO) and the USA. High concentrations of antibiotics in the sludge would have negative impacts on the environment if the sludge were applied on agricultural land, including effects on soil microbial diversity, respiration and denitrification due their antimicrobial activities Kotzerke et al, 2011;Zielezny et al, 2006).…”