Streptomyces sp.MJM3502 is a promising producer of rufomycins,which are a class of potent anti-tuberculosis lead compounds.Although the structure,activity,and mechanism of the main rufomycin 4/6 and its analogs have b...Streptomyces sp.MJM3502 is a promising producer of rufomycins,which are a class of potent anti-tuberculosis lead compounds.Although the structure,activity,and mechanism of the main rufomycin 4/6 and its analogs have been extensively studied,a significant gap remains in our understanding of the genome sequence and biosynthetic pathway of Streptomyces sp.MJM3502,and its metabolic engineering has not yet been reported.This study established the genetic manipulation platform for the strain.Using CRISPR/Cas9-based technology to in-frame insert the strong kasO^(*)p promoter upstream of the rufB and rufS genes of the rufomycin BGC,we increased rufomycin 4/6 production by 4.1-fold and 2.8-fold,respectively.Furthermore,designing recombinant strains by inserting the kasO^(*)p promoter upstream of the biosynthetic genes encoding cytochrome P450 enzymes led to new rufomycin derivatives.These findings provide the basis for enhancing the production of valuable natural compounds in Streptomyces and offer insights into the generation of novel active natural products via synthetic biology and metabolic engineering.展开更多
Objective:To investigate the antioxidant activity of soil-borne aetinobacteria.Methods:The total phenolic contents,the level of antioxidant potential by DPPH radical scavenging activity,MO scavenging activity,and ABTS...Objective:To investigate the antioxidant activity of soil-borne aetinobacteria.Methods:The total phenolic contents,the level of antioxidant potential by DPPH radical scavenging activity,MO scavenging activity,and ABTS radical scavenging activity in ethyl acelale extract were determined.Results:The 16 S rDNA sequencing analysis revealed that Streptomyces sp.strain MJM 10778.which was isolated from Hambak Mountain.Korea,has 99.9% similarity to Streptomyces misionensis(S.misionenis) NBRC 13063.The physiological and the morphological test revealed that the strain MJM 10778 has different characteristics from the strain NBRC.13063.The entire antioxidant assay with the ethyl acelale extract displayed good radical scavenging activity.The IC_(50) values of the strain MJM 10778 extract on DPPH,.NO.and ABTS radicals were identified to he 92.8 μg/mL,0.02 μg/ml,and 134.9 μg/mL,respectively.The ethyl acetate extract of the strain MJM 10778 showed an 81.500% of cell viability at 100 μg/mL in Raw264.7cell viability assay.Conclusions:The results obtained suggesl that the ethyl acetate extract of Streptomyces sp.strain MJM 10778 could be considered as a potential source of drug for the diseases that is caused by free radicals with its anti-oxidant activities and low cytotoxicity.展开更多
基金supported by grants from“Cooperative Research Program for Agriculture Science and Technology Development(Project No.PJ01319101)”Rural Development Administration,Republic of KoreaThe National Natural Science Foundation of China(Project No.31600038)+1 种基金the Key Research Development Program of the Natural Science Basic Research Plan in Shaanxi Province of China(Project No.2021NY-196)funding of their anti-TB cyclopetide research by grant U19AT142735.
文摘Streptomyces sp.MJM3502 is a promising producer of rufomycins,which are a class of potent anti-tuberculosis lead compounds.Although the structure,activity,and mechanism of the main rufomycin 4/6 and its analogs have been extensively studied,a significant gap remains in our understanding of the genome sequence and biosynthetic pathway of Streptomyces sp.MJM3502,and its metabolic engineering has not yet been reported.This study established the genetic manipulation platform for the strain.Using CRISPR/Cas9-based technology to in-frame insert the strong kasO^(*)p promoter upstream of the rufB and rufS genes of the rufomycin BGC,we increased rufomycin 4/6 production by 4.1-fold and 2.8-fold,respectively.Furthermore,designing recombinant strains by inserting the kasO^(*)p promoter upstream of the biosynthetic genes encoding cytochrome P450 enzymes led to new rufomycin derivatives.These findings provide the basis for enhancing the production of valuable natural compounds in Streptomyces and offer insights into the generation of novel active natural products via synthetic biology and metabolic engineering.
基金supported by a grant from next-generation BioGreen 21 pmjcet(No.PJ009643).RDA Korea
文摘Objective:To investigate the antioxidant activity of soil-borne aetinobacteria.Methods:The total phenolic contents,the level of antioxidant potential by DPPH radical scavenging activity,MO scavenging activity,and ABTS radical scavenging activity in ethyl acelale extract were determined.Results:The 16 S rDNA sequencing analysis revealed that Streptomyces sp.strain MJM 10778.which was isolated from Hambak Mountain.Korea,has 99.9% similarity to Streptomyces misionensis(S.misionenis) NBRC 13063.The physiological and the morphological test revealed that the strain MJM 10778 has different characteristics from the strain NBRC.13063.The entire antioxidant assay with the ethyl acelale extract displayed good radical scavenging activity.The IC_(50) values of the strain MJM 10778 extract on DPPH,.NO.and ABTS radicals were identified to he 92.8 μg/mL,0.02 μg/ml,and 134.9 μg/mL,respectively.The ethyl acetate extract of the strain MJM 10778 showed an 81.500% of cell viability at 100 μg/mL in Raw264.7cell viability assay.Conclusions:The results obtained suggesl that the ethyl acetate extract of Streptomyces sp.strain MJM 10778 could be considered as a potential source of drug for the diseases that is caused by free radicals with its anti-oxidant activities and low cytotoxicity.
