摘要:
为了评价鸭粪中残留的环丙沙星(ciprofloxacin,CIP)对土壤微生物群落功能多样性的影响,布置培养试验,设五个处理,分别是Ⅰ:CK (对照)、Ⅱ:CIP (人工添加的CIP)、Ⅲ:DF (添加不含抗生素的鸭粪)、Ⅳ:DF+CIP (在Ⅲ的基础上再外源添加CIP)、Ⅴ:DF (CIP)(粪源CIP即含有CIP的鸭粪),培养81 d。借助Biolog技术研究了不同来源的CIP对土壤微生物功能多样性的影响。结果表明,培养1 d后,反映土壤微生物活性的平均颜色变化率(AWCD)表现为DF > DF+CIP > DF (CIP) > CK > CIP,说明环丙沙星对土壤微生物活性具有一定的抑制作用,且随着培养时间的延长其抑制作用减弱;添加鸭粪显著增强了土壤微生物活性和群落功能多样性;与人工添加进鸭粪中的环丙沙星相比,粪源环丙沙星对微生物活性的抑制作用更强,并显著降低了土壤中利用碳源微生物的物种丰富度指数(H)、均匀度指数(E)、优势度指数(Ds)和碳源利用丰富度指数(S);在培养过程中,土壤微生物利用的主要碳源种类随培养时间延长有所变化,初期利用的主要是糖类、羧酸类、聚合物类、胺类以及氨基酸类,后期主要是糖类和羧酸类。
Abstract:
A 81-day soil culture experiment was conducted with 5 treatments:CK (control), CIP (ciprofloxacin), DF (duck feces), DF + CIP (DF adding CIP) and DF(CIP) (DF containing CIP), through which functional diversity of soil microbial communities was studied using the BIOLOG Microbial Identification System to evaluate the effects of ciprofloxacin from different sources. Results showed that AWCD (Average Well Color Development) after incubation for 1 day followed order as DF > DF + CIP > DF(CIP) > CK > CIP, indicating soil microbial activity was inhibited by CIP whose influence decreased in subsequent experiment. Addition of duck feces significantly enhanced soil microbial activity and community functional diversity. Compared with ciprofloxacin added into duck feces, the inhibition effect of duck fecal-borne ciprofloxacin on microbial activity was stronger. Also duck fecal-borne ciprofloxacin caused significant reduces of several diversity indices such as Shannon index (H), substrate richness (S), substrate evenness (E) and Simpson's dominance (Ds). During incubation period, the main carbon sources utilized by microorganisms in soil changed from carbohydrates, carboxylic acids, polymers, amines and amino acids to carbohydrates and carboxylic acids.