Microecological Characteristics In Rhizosphere Of Chinese Flowering Cabbage With High/Low Accumulation Of Ciprofloxacin

Quinolone antibiotics are widely used in human health and animal farming, each year alarge number of antibiotics through a variety of ways have been discharged into environment andpersist in it. In agricultural production, animal manure is widely used as an organic fertilizer,which caused soil contamination and been absorbed and accumulated in vegetables, the existenceof potential hazards on human health can not be ignored.Based on our prior outcomes，we have screened with the Chinese flowering cabbage whichwas high or low accumulation of ciprofloxacin, but its mechanism isn’t clear. Therefore, wechoose indoor potted analog experiment, add ciprofloxacin in soil to set pollution level I(5mg/kg), pollution level II (20mg/kg), pollution level III (80mg/kg) and control of fourtreatments, research the micro-ecological effects of high/low accumulation of ciprofloxacin inChinese flowering cabbage rhizosphere. Aims to explore rhizosphere microecological effect onthe environmental behavior of ciprofloxacin in the soil-plant-microbial system and the feasibilityof ecological restoration of antibiotic-contaminated soil, provide new ideas and technicalsupports on bioremediation of antibiotics polluted environment. After50d indoor pot experiment,the research results are as follows:(1) The content of ciprofloxacin in two Chinese flowering cabbage roots is the highest, thenis stem, and the least is leaves. The content of ciprofloxacin in Youqingsijiu flowering cabbageare higher than Youlvcutai flowering cabbage, but the content of ciprofloxacin in soil whichcultivate Youlvcutai flowering cabbage is higer. So, Youqingsijiu flowering cabbage wasselected as the cultivar with high accumulation of ciprofloxacin, and Youlvcutai floweringcabbage was considered as the cultivar with low accumulation of ciprofloxacin.(2) Ciprofloxacin inhibits soil catalase and urease activity, and the inhibition werestrengthened with the increasing of concentration of ciprofloxacin. During the period of Chineseflowering cabbage growth, the soil catalase and urease activity were shown a trend with“increase ahead and reduce follow”; low concentration of ciprofloxacin treatment (5mg/kg)promotes the soil catalase and urease activity of Chinese flowering cabbage rhizosphere, andhigh concentration of ciprofloxacin treatment (80mg/kg) inhibits the activity of two enzymes.The soil catalase and urease activity of Youqingsijiu flowering cabbage rhizosphere are higher than Youlvcutai flowering cabbage, but the difference is not significant.(3) Ciprofloxacin inhibits the number of bacteria and fungi in the soil, and its inhibitionwith increasing concentration of ciprofloxacin enhanced. The number of soil bacteria and fungiwere shown a trend with “increase ahead and reduce follow”, too.Soil bacteria community structure showed some differences in different ciprofloxacinconcentration treatments through DGGE molecular biology method. High concentration ofciprofloxacin treatment (80mg/kg) inhibits the soil bacteria DGGE bands and bacteriacommunity structure, while the low concentration ciprofloxacin treatment (5mg/kg) promotessoil bacteria number of bands. The soil bacteria DGGE bands of Youqingsijiu flowering cabbagerhizosphere are higher than Youlvcutai flowering cabbage. Clone and sequencing results showedthat the Proteobacteria and Actinobacteria are the most important group of soil bacteria,Firmicutes、Acidobacteria and Dictyoglomi are also founded。...