|Pils, Jutta - IOWA STATE UNIVERSITY|
Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 4, 2004
Publication Date: November 4, 2004
Citation: Pils, J.R., Laird, D.A., Moorman, T.B. 2004. Degradation of tetracycline sorbed on k- and ca-saturated soils and soil components [CD-ROM]. ASA-CSSA-SSSA Annual Meeting Abstracts. Madison, WI. Technical Abstract: Extensive use of Tetracycline (TC) as a growth promoter and therapeutic agent in animal husbandry has raised concerns about the potential for breeding antibiotic resistant bacteria. Previous batch equilibration studies showed that at least 98% of added TC was sorbed on, and 1% desorbed from, calcium (Ca) and potassium (K)- saturated soil components (clay, humic colloids, and clay-humic complexes). Our hypothesis is that sorption onto natural soil colloids regulates both mobility and biotic/abiotic degradation of TC in soil. Not much scientific work has been conducted focusing on the biodegradation of sorbed TC. Several papers (Pinck et al, 1961, Soulides et al, 1961a,b), however, indicate that sorbed TC loses its activity, and that the degree of inactivation depends on the quantity of TC in the soil and the specific clay mineralogy (Batchelder, 1982). Preliminary studies in our lab suggest that antimicrobial activity is retained upon sorption onto soil colloids suggesting a need for further study. Thus, our objectives are to: i) determine antimicrobial activity of sorbed TC and its ability to act as a growth inhibitor for natural soil bacteria, ii) investigate whether sorbed TC represents a long-term sink for slow TC release, and iii) elucidate efficiency of resistant bacteria to degrade sorbed 3H-TC. Results will be presented for a study in which 3H-TC sorbed to soil components was incubated under sterile conditions and in the presence of bacteria known to degrade TC.