title: Soil microbial response to tetracycline in two different soils amended with cow manure.
abstract: High amounts of antibiotics are introduced in the soil environment by manure amendment, which is the most important spreading route in soil, with a potential ecotoxicological impact on the environment. The objectives of this study were (a) to assess the tetracycline (Tc) bioavailability in a clay and in a sandy soil, and (b) to evaluate the effects of the Tc and cow manure on the structure and function of soil microbial communities. Clay and sandy soils were spiked with Tc at the concentrations of 100 and 500 mg Tc kg(-1) soil, and were amended or not with cow manure. The clay soil showed greater Tc sorption capacity and bioavailable Tc was between 0.157 and 4.602 mg kg(-1) soil. Tc dose and time-dependent effects on soil microbial communities were investigated by fluorescein diacetate activity, phospholipid fatty acids analysis, as well as by Biolog community level physiological profile and microbial counts at 2, 7 and 60 days after Tc and/or manure addition. The added Tc caused detrimental effect on the microbial activity and structure, particularly in the short term at the highest concentrations. However, the Tc effect was transient' it decreased after 7 days and totally disappeared within 60 days. Cow manure shifted the bacterial structure in both soils, increased the microbial activity in clay soil and contributed to recover the microbial structure in Tc-spiked manure treatments.
authors.affiliation: Department of Agriculture, University of Sassari, Viale Italia 39, 07100, Sassari, Italy. luigi.chessa@uniss.it.
authors.forename: Luigi
authors.initials: L
authors.lastname: Chessa
authors.affiliation: Department of Agriculture, University of Sassari, Viale Italia 39, 07100, Sassari, Italy.
authors.forename: Alba
authors.initials: A
authors.lastname: Pusino
authors.affiliation: Department of Agriculture, University of Sassari, Viale Italia 39, 07100, Sassari, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Garau
authors.affiliation: Department of Agriculture, University of Sassari, Viale Italia 39, 07100, Sassari, Italy.
authors.forename: Nicoletta Pasqualina
authors.initials: NP
authors.lastname: Mangia
authors.affiliation: Department of Agriculture, University of Sassari, Viale Italia 39, 07100, Sassari, Italy.
authors.forename: Maria Vittoria
authors.initials: MV
authors.lastname: Pinna
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis* / Q000494:pharmacology; D002417:Cattle; D005308:Fertilizers; D007558:Italy; D008372:Manure; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis* / Q000494:pharmacology; D013752:Tetracycline / Q000032:analysis* / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D005308:Fertilizers; D008372:Manure; D012987:Soil; D012989:Soil Pollutants; D013752:Tetracycline
keywords: Antibiotic ecotoxicological effect; Bioavailability; Cow manure; Microbial activity; Microbial fingerprint; Soil; Tetracycline