[Objective] The aim was to identify the species diversity of Actinomycetes from Mangrove forest in Beihai,Guangxi Province. [Method] 10 strains of typical Actinomycetes were isolated from Mangrove forest soil,and the ...[Objective] The aim was to identify the species diversity of Actinomycetes from Mangrove forest in Beihai,Guangxi Province. [Method] 10 strains of typical Actinomycetes were isolated from Mangrove forest soil,and the Actinomycetes genomic DNA was successful extracted. 16S rDNA was amplified by PCR and sequenced by Sanger dideoxy sequencing method. [Result] All the sequences were blasted in genbank,eight strains belonged to the genus of Streptomyces (80%),and two strains belonged to the genus of Nocardiopsis (20%). [Conclusion] There are many different Actinomycetes species in Mangrove forest soil samples in Beihai,Guangxi Province.展开更多
Ten actinomycete strains isolated from the Yellow Sea off China＇s coasts were identified as belonging to two genera by 16S rDNA phylogenetic analysis： Streptomyces and Nocardiopsis. Six Streptomyces strains （MA10, ...Ten actinomycete strains isolated from the Yellow Sea off China＇s coasts were identified as belonging to two genera by 16S rDNA phylogenetic analysis： Streptomyces and Nocardiopsis. Six Streptomyces strains （MA10, 2SHXF01-3, MA35, MA05-2, MA05-2-1 and MA08-1） and one Nocardiopsis strain （MA03） were predicted to have the potential to produce aromatic polyketides based on the analysis of the KSa （ketoacyl-synthase） gene in the type II PKS （polyketides synthase） gene cluster. Four strains （MA03, MA01, MA10 and MA05-2） exhibited significant inhibitory effects on mycelia growth （inhibition rate 〉50%） and subsequent aria- toxin production （inhibition rate 〉75%） of the mutant aflatoxigenic Aspergillus parasiticus NFRI-95. The ethyl acetate extracts of the broth of these four strains displayed significant inhibitory effects on mycelia growth, and the IC50 values were calculated （MA03： 0.275 mg mL-1, MA01：0.106 mg mL-1, MA10：1.345 mg mL-1 and MA05-2：1.362 mg mL-1）. Five strains （2SHXF01-3, MA03, MA05-2, MA01 and MA08-1） were selected based on their high cytotoxic activities. The ethyl acetate extract of the Nocardiopsis strain MA03 was particularly noted for its high antitumor activity against human carcinomas of the cervix （HeLa）, lung （A549）, kidney （Caki-1） and liver （HepG2） （IC50： 2.890, 1.981, 3.032 and 2.603 μgmL-1, respectively）. The extract also remarkably inhibited colony formation of HeLa cells at an extremely low concentration （0.5μgmL 1）. This study highlights that marine-derived actinomycetes are a huge resource of compounds for the biological control of aflatoxin contamination and the development of novel drugs for human carcinomas.展开更多
基金Supported by Science Foundation of Guangxi Province (0899006)South China Agricultural University Principal Foundation ( 5100-k05099)~~
文摘[Objective] The aim was to identify the species diversity of Actinomycetes from Mangrove forest in Beihai,Guangxi Province. [Method] 10 strains of typical Actinomycetes were isolated from Mangrove forest soil,and the Actinomycetes genomic DNA was successful extracted. 16S rDNA was amplified by PCR and sequenced by Sanger dideoxy sequencing method. [Result] All the sequences were blasted in genbank,eight strains belonged to the genus of Streptomyces (80%),and two strains belonged to the genus of Nocardiopsis (20%). [Conclusion] There are many different Actinomycetes species in Mangrove forest soil samples in Beihai,Guangxi Province.
基金supported by the COMRA project (No. DY125-15-R-01)
文摘Ten actinomycete strains isolated from the Yellow Sea off China＇s coasts were identified as belonging to two genera by 16S rDNA phylogenetic analysis： Streptomyces and Nocardiopsis. Six Streptomyces strains （MA10, 2SHXF01-3, MA35, MA05-2, MA05-2-1 and MA08-1） and one Nocardiopsis strain （MA03） were predicted to have the potential to produce aromatic polyketides based on the analysis of the KSa （ketoacyl-synthase） gene in the type II PKS （polyketides synthase） gene cluster. Four strains （MA03, MA01, MA10 and MA05-2） exhibited significant inhibitory effects on mycelia growth （inhibition rate 〉50%） and subsequent aria- toxin production （inhibition rate 〉75%） of the mutant aflatoxigenic Aspergillus parasiticus NFRI-95. The ethyl acetate extracts of the broth of these four strains displayed significant inhibitory effects on mycelia growth, and the IC50 values were calculated （MA03： 0.275 mg mL-1, MA01：0.106 mg mL-1, MA10：1.345 mg mL-1 and MA05-2：1.362 mg mL-1）. Five strains （2SHXF01-3, MA03, MA05-2, MA01 and MA08-1） were selected based on their high cytotoxic activities. The ethyl acetate extract of the Nocardiopsis strain MA03 was particularly noted for its high antitumor activity against human carcinomas of the cervix （HeLa）, lung （A549）, kidney （Caki-1） and liver （HepG2） （IC50： 2.890, 1.981, 3.032 and 2.603 μgmL-1, respectively）. The extract also remarkably inhibited colony formation of HeLa cells at an extremely low concentration （0.5μgmL 1）. This study highlights that marine-derived actinomycetes are a huge resource of compounds for the biological control of aflatoxin contamination and the development of novel drugs for human carcinomas.
