Cycloheximide inhibition of peptone-induced nitrate production across a soil moisture gradient

The antibiotic block technique is used to distinguish between fungal and bacterial induced activity. In the present study, the antibiotic inhibition of peptone-induced NO₃^– production was tested across a soil moisture gradient. Soil was incubated at 60, 80, 90 and 100% water-filled pore space (WFPS) and as a water slurry. Peptone was used as the substrate and cycloheximide and C₂H₂ (0.1% v/v) were added to inhibit fungal and autotrophic nitrification, respectively, the latter being considered mainly of bacterial origin. At all moisture contents is more than 80% of NO₃^– production was due to autotrophic nitrification. At increasing water contents the percentage of NO₃^– production inhibited by C₂H₂ increased, whereas the percentage inhibited by cycloheximide decreased from 26.4% at 60% WFPS to 4.6% in the water slurry, suggesting a different sensitivity of bacterial and fungal nitrification to soil moisture. Although no direct evidence of an alteration in the fungal population was produced in this experiment, data proved that water content influences the result of the test and hence care should be taken when comparing data using different test conditions.     

饲用抗生素替代物在养猪生产中的应用研究进展

养猪生产中抗生素的使用带来了巨大的危害和经济损失,在即将到来的无抗养殖背景下,寻求养猪生产中的抗生素替代物成为研究热点之一。文章结合近年相关研究,总结了植物提取物、寡糖和多糖、微生态制剂、中草药提取物、抗菌肽、酸化剂以及酶制剂等潜在的饲用抗生素可替代物在养猪生产中的应用效果,以期为养猪生产中配制无抗日粮提供策略和参考依据,促进养猪生产实现无抗养殖。     

中草药添加剂代替抗生素饲喂保育猪的效果

本试验旨在探索中草药添加剂代替抗生素添加剂饲喂保育仔猪后,对仔猪生长、发育及疾病防治效果的影响。结果发现,试验组（添加2%中草药添加剂）的发病率和死亡率明显低于对照组（添加0.1%土霉素粉）,增重高于对照组（P〈0.01）,增重成本低于对照组1.56元/kg,经济效益提高18%。     

Veterinary antibiotics at environmentally relevant concentrations inhibit soil iron reduction and nitrification

Veterinary antibiotics used in food animal production, subsequently entering the agroecosystem through land application of animal manure, constitute a growing concern. Previous studies have reported inhibitory effects of antibiotics on soil microbial activities, however, treatment concentrations in these studies were often many times greater than the ranges typically found in the environment. When spiked into manure and mixed with soil at environmentally relevant concentrations in a laboratory study, sulfadimethoxine and monensin blocked soil iron reduction over periods extending from a few days to the entire 50-Day experiment. Sulfadimethoxine also had an inhibitory effect on soil nitrification periodically over the course of the study. Respiration and community-level physiological profile parameters were not inhibited by sulfadimethoxine, monensin, or chlortetracycline. We conclude that antibiotics at environmentally relevant concentrations can disrupt soil microbial processes, although the detection of such impact may be antibiotic and/or process specific.     

有机肥料中抗生素在农田土壤和植物间的迁移研究

总结国内外关于抗生素对农田土壤、植物的影响以及抗生素在有机肥料、农田土壤和农田植物中的迁移。研究表明,将有机肥料应用于农田之前,应尽量减少抗生素在有机肥料中的含量,使抗生素对农田环境的影响降到最低。     

丹参醇提物的抗菌作用研究

从丹参中提取醇溶性成分,采用微量稀释法探究丹参醇提物与8种抗生素联合对五种菌的体外抗菌活性。结果表明：丹参醇提物单独用药抑菌效果不佳,而与其他抗生素连用均展现不同抑菌效果;与头孢噻肟钠连用,使抑菌效果提高了6倍。浓度处于0.5 mg·mL^-1时控制效果最佳,肺炎克雷伯菌的菌丝生物量减少13倍左右。研究结果可为丹参醇提物的临床应用提供参考。     

一株抗生素制药工业废水高效降解菌筛选及生物特性研究

[目的]从抗生素废水处理的活性污泥中筛选出具有高效降解能力的菌株。[方法]从抗生素制药工业废水处理的活性污泥中分离到1株抗生素高效降解菌NG3,对其进行形态学、生理生化鉴定和16SrDNA序列比对分析,同时对该菌株的生物学特性进行初步研究。[结果]从抗生素制药工业废水处理的活性污泥中分离得到1株抗生素高效降解菌NG3,经形态学、生理生化鉴定和16SrDNA序列比对分析,确定该菌株属于不动杆菌属(Acinetobacter sp.),命名为Acinetobacter sp.NG3。[结论]为抗生素类工业废水高效处理提供借鉴。     

抗生素替代品微生态制剂在养猪业中的应用

虽然抗生素对养殖业、饲料业的发展起到积极的促进作用,但其本身也有无法克服的弊端,因此饲料中禁止使用抗生素是必然趋势。综述了抗生素替代品——微生态制剂的概念、作用机理及其在仔猪、生长育肥猪和母猪上的应用。