The veterinary antibiotic oxytetracycline and Cu influence functional diversity of the soil microbial community

Abstract

Oxytetracycline reduces the functional diversity of soil microbial community, and the combination of Cu and oxytetracycline leads to a further reduction. AbstractThere are increasing concerns over the effects of veterinary antibiotics and heavy metals in agricultural soils. The widely used veterinary antibiotic oxytetracycline (OTC), Cu and their combination on soil microbial community function were assessed with the Biolog method. The microbial community was extracted from the soil and exposed to a 0.85% sodium chloride solution containing OTC (0, 1, 5, 11, 43, 109 and 217 mM), or Cu (0, 10, 20, 100 and 300 mM), or combination of the two pollutants (OTC 0, 5, 11 mM and Cu 0, 20 mM). Functional diversity, evenness, average well color development (AWCD) and substrate utilization decreased significantly with increasing concentrations of OTC or Cu ( p < 0.005). The critical concentrations were 11 mM for OTC and 20 mM for Cu. The combination of OTC and Cu significantly decreased Shannon's diversity, evenness and utilization of carbohydrates and carboxylic acids compared to individual one of the contaminants. The antibiotic OTC and Cu had significant negative effects on soil microbial community function, particularly when both pollutants were present.

Changes in functional diversity of soil microbial community with addition of antibiotics sulfamethoxazole and chlortetracycline

“…Low oxytetracycline concentration (11 μM) might have significant effects on the microbial community in solution (Kong et al 2006). In the present study, the two tested antibiotics were directly spiked into soil, and less inhibitory effectiveness on soil microbial community function was found.…”

“…The existence of copper would enhance antibiotic negative effect on functional diversity of soil microbial community (Kong et al 2006). It was also reported that combination of cypermethrin and heavy metals could result in great reduction of functional diversity (Xie et al 2009).…”

“…This could be attributed to the decrease in antibiotic concentration in the soil and microbial adaptation to antibiotic disturbance (Halling-Sørensen et al 2003;Thiele-Bruhn and Beck 2005). In the case of the control treatment (with no antibiotic addition), the mean values of AWCD and Shannon index of day 21 were lower than those of day 7, which suggested that soil microbial activities decreased due to the suboptimal nutritional status after a longer incubation period (Hammesfahr et al 2008;Kong et al 2006). In the present study, antibiotic addition caused an improvement of soil microbial community function than the control in the late incubation period.…”

Wastewater reuse in irrigation: A microbiological perspective on implications in soil fertility and human and environmental health

“…Leaching is an-other possible consequence of metal accumulation in soils, mainly after long periods (~20 years) of irrigation with wastewater (Xu et al, 2010). Moreover, accumulated metals may interact synergistically with other contaminants, such as antibiotics, exacerbating their potential effects (Kong et al, 2006;Peltier et al, 2010). Boron is a semi-metallic element and also a pollutant commonly present in wastewater (EPA, 2012;WHO, 2006a).…”

“…Antimicrobial compounds in soils may disturb the structure and activity of microbial communities (Ding and He, 2010;Kong et al, 2006;Liu et al, 2012;Müller et al, 2002) (Table 3). Indeed, disturbances on N transformation, methanogenesis, and sulphate reduction were reported (Ding and He, 2010).…”