排序方式： 共有4条查询结果，搜索用时 15 毫秒
1
1.
Xue-Gong Li Xiao-Min Tang Jing Xiao Guang-Hui Ma Li Xu Shu-Jie Xie Min-Juan Xu Xiang Xiao Jun Xu 《Marine drugs》2013,11(10):3875-3890
Mangrove-derived actinomycetes are promising sources of bioactive natural products. In this study, using homologous screening of the biosynthetic genes and anti-microorganism/tumor assaying, 163 strains of actinomycetes isolated from mangrove sediments were investigated for their potential to produce halogenated metabolites. The FADH2-dependent halogenase genes, identified in PCR-screening, were clustered in distinct clades in the phylogenetic analysis. The coexistence of either polyketide synthase (PKS) or nonribosomal peptide synthetase (NRPS) as the backbone synthetases in the strains harboring the halogenase indicated that these strains had the potential to produce structurally diversified antibiotics. As a validation, a new enduracidin producer, Streptomyces atrovirens MGR140, was identified and confirmed by gene disruption and HPLC analysis. Moreover, a putative ansamycin biosynthesis gene cluster was detected in Streptomyces albogriseolus MGR072. Our results highlight that combined genome mining is an efficient technique to tap promising sources of halogenated natural products synthesized by mangrove-derived actinomycetes. 相似文献
2.
为满足恩拉霉素工业化生产对高产菌株的需求,采用N+注入技术和单因素及正交试验方法对产恩拉霉素链霉菌(Streptomyces sp.)NJWGY3665进行诱变,并对目的菌株的最佳发酵条件进行优化。结果表明:随N+注入剂量的增加,菌株的存活率呈典型的马鞍型剂量-效应曲线。在最佳注射剂量120×1013ions/cm2条件下筛选到1株具有遗传稳定性的高产链霉菌突变菌株LD1;该菌株发酵最适培养基条件为蔗糖50g/L,酵母粉20g/L,NaCl 1.5g/L,FeSO_40.5g/L;最佳发酵条件为转速190r/min,温度28℃,pH 7,接种量8%。在此条件下,发酵液恩拉霉素浓度达11 860μg/mL。 相似文献
3.
The national standard pinella mildew element biological detection method was improved, using dry filter paper method instead of cylinder plate method, the potassium content of different samples of pinella mold were determined,and the extract composition, extraction time, the concentration of bacteria test and other factors influence on the test results of the established enramycin between concentration and the antibacterial circle diameter of linear equations was studied. The results showed that using acetone extraction liquid acetone (A:1 mol/mL HCl:water =35:12:56, pH value was adjusted to 3.0 with 1 mol/mL HCl) leaching provided sample, extraction time of 3.5 h could fully immersed test of enramycin. Use of biological indicator bacteria CMCC (B) 63501 spore count of 3.4×107 per mL of the measurement of living flat dish, the formation of the inhibitory circle edge rule was clear, good accuracy. Using dry filter paper method could effectively eliminate the extraction or dilute acidic fluid itself to detect strains inhibitory effect, and the utility model had the advantages of simple operation, good repeatability. It could be used for large quantities of samples of enramycin content determination.Enramycin standard solution at concentrations for 150~500 U/mL and its bacteriostatic circle diameter and valence have good linear regression.The resulting regression equation was Y=0.00944X+11.55344, the correlation coefficient was R=0.9962, the final effective range was 0.75~2.5 U, the measured results were more close to the true value.It could be used as an efficient enduracidin determination method, worthy of promotion and use. 相似文献
4.
试验对国家标准中恩拉霉素的生物检测方法进行了改进,以干燥滤纸片法代替管碟法对不同样品中的恩拉霉素含量进行了测定;并研究了浸提液组成、浸提时间、检定菌浓度等因素对检测结果的影响,建立了恩拉霉素浓度与抑菌圈直径之间的线性方程。研究结果表明,利用丙酮浸提液A（丙酮：1 mol/mL HCl：水=35：12：56,用1 mol/mL HCl将pH调至3.0）浸提供试品,浸提时间3.5 h,可以充分浸提供试品中的恩拉霉素;使用生物测定指示菌CMCC（B）63501芽孢数为3.4×107个/mL的平皿,形成的抑菌圈边缘规则清晰,准确度好;使用干燥滤纸片法可有效消除浸提液或酸性稀释液本身对检测菌株的抑制作用,且操作简单、重复性好,可以同时对大批量的样品进行恩拉霉素含量的测定。恩拉霉素标准溶液在浓度为150~500 U/mL的范围内,其产生的抑菌圈直径与效价有较好的线性回归性,所得回归方程：Y=0.00944X+11.55344,相关系数R=0.9962,最终有效区间是0.75~2.5 U,测得的结果更接近真实值,可作为一种高效、快速的恩拉霉素含量测定方法,值得推广和使用。 相似文献
1