针对土壤中抗生素污染日益严重的问题,为了促进土壤中抗生素监测技术体系及相关标准的完善,建立了一种QuEChERS结合超高效液相色谱-串联质谱(UPLC-MS/MS)的分析方法。土壤样品用10 mL 3%(体积分数,下同)氨化乙腈提取,0.2 g PSA和0.2 g无...针对土壤中抗生素污染日益严重的问题,为了促进土壤中抗生素监测技术体系及相关标准的完善,建立了一种QuEChERS结合超高效液相色谱-串联质谱(UPLC-MS/MS)的分析方法。土壤样品用10 mL 3%(体积分数,下同)氨化乙腈提取,0.2 g PSA和0.2 g无水MgSO4净化,流动相为甲醇-水(1∶1,体积比,下同),ZORBAX SB-Aq(2.1 mm×150 mm,3.5μm)色谱柱,质谱条件为电喷雾离子源(ESI)、正/负离子扫描、多反应监测(MRM)。结果表明,4种分析物在0.1~200 ng/mL范围内线性关系良好,相关系数(r)>0.999,检出限(LOD)为0.01~0.06μg/kg,定量限(LOQ)为0.05~0.19μg/kg,在3个加标水平(0.4,8.0,40.0μg/kg)下,平均回收率为87.23%~108.57%,相对标准偏差(RSD,n=5)为0.36%~6.55%。该方法准确、简便、高效、灵敏,适用于土壤中氯霉素、甲砜霉素、氟苯尼考及其代谢物氟苯尼考胺的同步检测,可为相关部门制定相关行业标准、规范提供数据依据。展开更多
Bacillus subtilis produces many chemlcally-dwerse seconaary metaDolltes or interest to chemists ano biologlsts. Based on this, this review gives a detailed overview of the natural components produced by B. subtilis in...Bacillus subtilis produces many chemlcally-dwerse seconaary metaDolltes or interest to chemists ano biologlsts. Based on this, this review gives a detailed overview of the natural components produced by B. subtilis including cyclic lipopeptides, polypeptides, proteins （enzymes）, and non-peptide products. Their structures, bioactive ac- tivities and the relevant variants as novel lead structures for drug discovery are also described. The challenging effects of fermentation metabolites, isolation and purification, as well as the overproduction of bioactive com- pounds from B. subtilis by metabolic engineering, ＇~ere also highlighted. Systematically exploring biosynthetic routes and the functions of secondary metabolites from 13. subtilis may not only be beneficial in improving yields of the products, but also in helping them to be used in food industry and public medical service on a large-scale.展开更多
Reverse transcription quantitative PCR （RT-qPCR） combined with the published genome information of Saccharopolyspora spinosa can allow sophisticated studies about S. spinosa, including Studying the regulation of spi...Reverse transcription quantitative PCR （RT-qPCR） combined with the published genome information of Saccharopolyspora spinosa can allow sophisticated studies about S. spinosa, including Studying the regulation of spinosyn biosynthesis, finding new target genes for engineering, and discovering and exploiting other macrolide secondary metabolites. Studies have demonstrated that appropriate internal control is needed to normalize target genes at transcription levels. However, many studies have shown that no single reference gene is universal for all strains under all experimental conditions. Thus, eight candidate reference genes of three different S. spinosa strains in two different cultures were studied to find suitable reference gene（sl. The number of amplification cycles of these candidate genes was calculated by BestKeeper, NormFinder and geNorm. The results indicated that the most suitable reference genes for normalization during the fermentation of S. spinosa were 16S rRNA and rbL13.展开更多
文摘针对土壤中抗生素污染日益严重的问题,为了促进土壤中抗生素监测技术体系及相关标准的完善,建立了一种QuEChERS结合超高效液相色谱-串联质谱(UPLC-MS/MS)的分析方法。土壤样品用10 mL 3%(体积分数,下同)氨化乙腈提取,0.2 g PSA和0.2 g无水MgSO4净化,流动相为甲醇-水(1∶1,体积比,下同),ZORBAX SB-Aq(2.1 mm×150 mm,3.5μm)色谱柱,质谱条件为电喷雾离子源(ESI)、正/负离子扫描、多反应监测(MRM)。结果表明,4种分析物在0.1~200 ng/mL范围内线性关系良好,相关系数(r)>0.999,检出限(LOD)为0.01~0.06μg/kg,定量限(LOQ)为0.05~0.19μg/kg,在3个加标水平(0.4,8.0,40.0μg/kg)下,平均回收率为87.23%~108.57%,相对标准偏差(RSD,n=5)为0.36%~6.55%。该方法准确、简便、高效、灵敏,适用于土壤中氯霉素、甲砜霉素、氟苯尼考及其代谢物氟苯尼考胺的同步检测,可为相关部门制定相关行业标准、规范提供数据依据。
基金Supported by the National Natural Science Foundation of China(21376215)the National Science and Technology Major Project of New Drug,China(2012ZX09103101-075)+2 种基金the Innovative Research Platform co-constructed by Zhejiang University and Taizhou City,and the Science and Technology Project of Zhejiang Province(2014C33174)the Major State Basic Research Development Program of China(2011CB710803)the National High-Tech Research and Development Program of China(2012AA022302)
文摘Bacillus subtilis produces many chemlcally-dwerse seconaary metaDolltes or interest to chemists ano biologlsts. Based on this, this review gives a detailed overview of the natural components produced by B. subtilis including cyclic lipopeptides, polypeptides, proteins （enzymes）, and non-peptide products. Their structures, bioactive ac- tivities and the relevant variants as novel lead structures for drug discovery are also described. The challenging effects of fermentation metabolites, isolation and purification, as well as the overproduction of bioactive com- pounds from B. subtilis by metabolic engineering, ＇~ere also highlighted. Systematically exploring biosynthetic routes and the functions of secondary metabolites from 13. subtilis may not only be beneficial in improving yields of the products, but also in helping them to be used in food industry and public medical service on a large-scale.
基金Supported by the National Natural Science Foundation of China(No.21076148 and 31270087)Plan for Tianjin Science and Technology Support(No.11ZCKFSY0100)
文摘Reverse transcription quantitative PCR （RT-qPCR） combined with the published genome information of Saccharopolyspora spinosa can allow sophisticated studies about S. spinosa, including Studying the regulation of spinosyn biosynthesis, finding new target genes for engineering, and discovering and exploiting other macrolide secondary metabolites. Studies have demonstrated that appropriate internal control is needed to normalize target genes at transcription levels. However, many studies have shown that no single reference gene is universal for all strains under all experimental conditions. Thus, eight candidate reference genes of three different S. spinosa strains in two different cultures were studied to find suitable reference gene（sl. The number of amplification cycles of these candidate genes was calculated by BestKeeper, NormFinder and geNorm. The results indicated that the most suitable reference genes for normalization during the fermentation of S. spinosa were 16S rRNA and rbL13.
