Abstrato

Soil Microbial Communities and Mineralization Responses to Penicillin and Tetracycline Loads

Qichun Zhang, Imran Haider Shamsi*, Huifang Zhou, Liquan Wei, Ziqi Zhu, Muhammad Faheem Adil, Zhangliang Kong

Residual effects of pharmaceutical antibiotics on soil microorganisms and turnover processes have merely been investigated. Therefore, this study explored the possible toxic effects of penicillin and tetracycline on indigenous bacterial communities and nitrogen mineralization in soil. Concentrations of 10 and 100 mg.kg-1 of penicillin and tetracycline antibiotics in soil affected the microbial community. The effect became apparent by a small tolerance increase and change in the phospholipids fatty acid (PLFA) pattern. The PLFA content revealed that most of the microbial groups decreased, while some specific microbial groups, e.g., 18:1ω9c, did not change in the soils even when soils were exposed to high concentrations of penicillin and tetracycline. Both antibiotics reduced the concentration of ammonium significantly, but that of nitrate was affected slightly. It was concluded that even at higher concentration, pharmaceutical antibiotics exert only a temporary pressure on soil microorganisms and selective processes in nitrogen turnover were negatively influenced