Center for Regional Environmental Research, National Institute for Environmental Studies , 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan.
Environ Sci Technol. 2014;48(1):350-7. doi: 10.1021/es403971s. Epub 2013 Dec 19.
In the present study, we investigated the effect of antibiotics on microbial arsenate (As(V)) reduction and arsenite (As(III)) oxidation in sediments collected from a small pond and eutrophic lake. The As(V)-reducing activities were less susceptible to chloramphenicol in aerobic conditions than in anaerobic conditions. Aerobic As(V) reduction proceeded in the presence of diverse types of antibiotics, suggesting that As-resistant bacteria are widely antibiotic resistant. In contrast, some antibiotics, e.g., chloramphenicol, strongly inhibited aerobic As(III) oxidation. In addition, bacterial As(III) oxidase genes were scarcely amplified and Proteobacteria -related 16S rRNA genes drastically decreased in chloramphenicol-amended cultures. Erythromycin and lincomycin, which successfully target many Gram-positive bacteria, scarcely affected As(III) oxidation, although they decreased the diversity of As(III) oxidase genes. These results indicate that the aerobic As(III) oxidizers in the sediment cultures are mainly composed of Proteobacteria and are more sensitive to certain types of antibiotics than the aerobic As(V) reducers. Our results suggest that antibiotic disturbance of environmental microbial communities may affect the biogeochemical cycle of As.
在本研究中，我们调查了抗生素对来自小型池塘和富营养化湖泊沉积物中微生物砷酸盐（As(V)）还原和亚砷酸盐（As(III)）氧化的影响。在有氧条件下，与厌氧条件相比，氯霉素对 As(V)还原活性的抑制作用较小。在存在多种类型抗生素的情况下，有氧 As(V)还原仍能进行，这表明耐砷细菌广泛具有抗生素抗性。相比之下，一些抗生素，如氯霉素，强烈抑制有氧 As(III)氧化。此外，在添加氯霉素的培养物中，细菌砷酸盐氧化酶基因很少被扩增，与变形菌纲相关的 16S rRNA 基因大幅减少。红霉素和林可霉素成功靶向许多革兰氏阳性菌，但对 As(III)氧化的影响较小，尽管它们降低了 As(III)氧化酶基因的多样性。这些结果表明，沉积物培养物中的好氧 As(III)氧化菌主要由变形菌纲组成，它们比好氧 As(V)还原剂对某些类型的抗生素更敏感。我们的结果表明，抗生素对环境微生物群落的干扰可能会影响砷的生物地球化学循环。
