Biotechnology Bulletin ›› 2021, Vol. 37 ›› Issue (11): 225-236.doi: 10.13560/j.cnki.biotech.bull.1985.2021-0288

Previous Articles     Next Articles

Isolation and Antibacterial Activity of Actinomycetes from the Nodules and Rhizosphere Soil of Hippophae rhamnoides in Tibet

LUO Ya-jun1(), SUN Hong-min2, HE Ning2, YUAN Li-jie1(), XIE Yun-ying2()   

  1. 1. School of Basic Medical Science,North China University of Science and Technology,Hebei Key Laboratory for Chronic Disease,Tangshan Key Laboratory for Preclinical and Basic Research on Chronic Disease,Tangshan 063210
    2. CAMS Key Laboratory of Synthetic Biology for Drug Innovation,Institute of Medicinal Biotechnology,Chinese Academy of Medical Sciences & Peking Union Medical College,Beijing 100050
  • Received:2021-03-11 Online:2021-11-26 Published:2021-12-03
  • Contact: YUAN Li-jie,XIE Yun-ying E-mail:592062203@qq.com;yuanlijie1970@163.com;xieyy@imb.pumc.edu.cn

Abstract:

In order to provide new microbial resources for the development of natural product drugs,the diversity and antibacterial activity of actinomycetes from the root nodules and rhizosphere soil samples of Hippophae rhamnoides in Nyingchi and Shannan of Tibet were explored. Dilution coating method was empployed to isolate the cultivable actinomycetes from 10 samples. After the 16S rRNA sequence alignment of the strains,the neighbor-joining method(N-J)was used to construct a phylogenetic tree to analyze the species diversity of actinomycetes. The microplate method was adapted to conduct fermentation and antibacterial activity evaluation of representative strains;and ultra-performance liquid chromatography-mass spectrometry(UPLC-MS)was to investigate the metabolites of active strains. A total of 112 strains of actinomycetes belonged to 23 genera,12 families and 7 orders were isolated from 10 samples,in which Streptomyces was the dominant genus. The results of antibacterial activity showed that 17 strains of estimated actinomycetes presented antibacterial activity against at least one of the tested bacteria,and the positive inhibition rate was 36.9%. Sixteen actinomycetes showed strong inhibitory activity against common clinical methicillin-resistant Staphylococcus aureus(MRSA),13 of which had higher inhibitory rate than the positive control drug vancomycin. In addition,7 of evaluated actinomycetes demonstrated inhibitory activity against carbapenem-resistant Acinetobacter baumannii(CRAB),from which Streptomyces sp. XZ19-363 had the strongest antibacterial activity against CRAB,with an inhibition rate of 91.3%. UPLC-MS analysis revealed that the strains with broad-spectrum antibacterial activities produced relatively abundant secondary metabolites in different media. The resources of cultivable actinomycetes from H. rhamnoides nodules and rhizosphere soils in Nyingchi and Shannan regions of Tibet both are rich and diverse,and possess promising antibacterial activities with rich metabolites.

Key words: Hippophae rhamnoides nodules, rhizosphere soil, actinobacteria, antibacterial activity