Effect of antibiotics on sedimentary microbiota as characterized by biomarker analysis.

抗生素用于治疗性和预防性处理的股票。由于饲料浪费和一些抗生素的低消化效率，相当大一部分药物可以释放到环境中并沉积到沉积物中。抗生素也被用来治疗孵化场的幼虫。在用含链霉素的海水处理贝类幼虫后，海水已排入邻近的沿海环境。因此，抗生素的使用及其在沉积物中的积累可能会影响天然沉积物微生物群。为了解抗生素对沉积物微生物生物量及其群落结构的影响，对添加不同浓度链霉素的沉积物进行了磷脂酯键脂肪酸（PLFA）分析。海水中的链霉素浓度高于沉积物中的浓度。此外，由于添加链霉素，孵育期间链霉素浓度增加。沉积物中的微生物生物量，总PLFA计算，减少了所有三个浓度的链霉素添加沉积物。微生物生物量的降低顺序为20 ppm > 10 ppm> 5 ppm。在孵育结束时，沉积物中的总PLFA水平（10和20 ppm链霉素）高或与对照值相当，表明沉积微生物种群可能已产生抗生素耐药性。沉积物中PLFA组的模式是不同的链霉素的三个浓度之间。PLFA剖面的聚类分析揭示了链霉素对沉积物微生物群落的影响。多维标度图的结果还表明，由于添加链霉素以及天然微生物群的破坏，PLFA谱发生了变化。

Antibiotics are used in both therapeutic and prophylactic treatment of the stocks. Because of wasted feed and low digestive efficiencies of some antibiotics, a substantial fraction of the drug can be released to the environment and is deposited to the sediment. Antibiotics are also used to treat the larvae in hatcheries. After treating the shellfish larvae in seawater containing streptomycin, the seawater has been discharged into the adjacent coastal environment. Thus antibiotic use and its accumulation in the sediment may influence the natural sedimentary microbiota. In order to know the impact of antibiotics on sedimentary microbial biomass, and its community structure, phospholipid ester-linked fatty acid(PLFA)analysis of sediment supplemented with different concentrations of streptomycin was carried out.Sediment parameters did not show significant changes during the incubation. Concentrations of streptomycin in seawater were higher than that in sediments. Furthermore, concentrations of streptomycin increased during the incubation period due to the addition of streptomycin. Sedimentary microbial biomass, as calculated by total PLFA, was decreased in all the three concentrations of streptomycin added sediments. The decrease of microbial biomass over control was in the order of 20 ppm > 10ppm > 5ppm. At the end of the incubation, levels of total PLFA in sediments(10 and 20 ppm streptomycin)were either high or comparable to the control values indicating that sedimentary microbial populations might have developed antibiotic resistance. The pattern of PLFA groups in sediments was different among the three concentrations of streptomycin used. Cluster analysis of PLFA profiles revealed the changes in microbial communities of sediments amended with streptomycin. The results of multidimensional scaling plot also indicated changes in PLFA profiles due to the addition of streptomycin and also disruption of the natural microbiota.