摘要：目的设计优化一种化学合成发酵培养基,为阿维菌素产生菌生理生化研究提供基础。方法在单因素实验的基础上运用响应面分析的方法,对9种因素进行Plackett-Burman设计筛选得到3个显著因子,并对其进行最陡爬坡试验和Box-Behnken试验,利用Design-Expert V8.06分析软件进行回归分析得到最优组合。结果优化后化学合成培养基的组成为:葡萄糖12g/L,麦芽糖18g/L,苏氨酸1.98g/L,50%乳酸钠0.5mL/L,K_2HPO_4·3H_2O 0.3g/L,MgSO_4·7H_2O 0.5g/L,NaCl 0.5g/L,FeSO_4·7H_2O0.01g/L,MnSO_4·H_2O 0.015g/L,MOPS 5g/L。结论经验证,该培养基的产素能力比目前的清亮培养基提高了397.4%,并具有透明清亮且产素稳定等特点,为以后阿维链霉菌的理论和生产研究奠定了基础。

摘要：Rapid and sensitive detection of various analytes is in high *** from its application in genome editing,CRISPR-Cas also shows promises in nucleic acid detection *** further exploit the potential of CRISPR-Cas for detection of diverse analytes,we present a versatile biosensing platform that couples the excellent affinity of aptamers for broad-range analytes with the collateral single-strand DNA cleavage activity of CRISPR-Cas12 *** demonstrated that the biosensors developed by this platform can be used to detect protein and small molecule in human serum with a complicated background,i.e.,the tumor marker alpha fetoprotein and cocaine with the detection limits of 0.07 fmol/L and 0.34 lmol/L,respectively,highlighting the advantages of simplicity,sensitivity,short detection time,and low cost compared with the state-of-the-art biosensing ***,this biosensing platform with plug-and-play design show great potential in the detection of diverse analytes.

摘要：微生物新药的产业化和高效制造是国家重大需求。然而天然产物作为次级代谢产物并非微生物生存所必需,以生存为目标的自然演化使微生物只在营养困乏期或者应激反应时才精确调控少量产生。尽管大量次级代谢产物的生物合成途径都得到了阐明,但初级代谢和次级代谢之间的转换机制仍不清楚,已成为制约细胞工厂高效生物制造药物的瓶颈。建立合成生物学5M策略和活细胞代谢实时监测工具是解决该科学问题的关键。本文聚焦链霉菌聚酮类化合物代谢转换机制的研究和智能制造,利用开发的系列特异性监测NAD(H)、NADP(H)的遗传编码荧光探针,详细解析了链霉菌胞内三酰甘油(TAGs)的降解机制,通过设计符合原子经济性原则的产物生物合成途径、动态精细调控等策略大幅度提高几种聚酮类药物(actinorhodin,jadomycin B和oxytetracycline)产量,其中阿维菌素B1a的工业生产效价提高了50%以上,达到有史以来最高的效价。