Taxonomy and Broad-Spectrum Antifungal Activity of Streptomyces sp. SCA3-4 Isolated From Rhizosphere Soil of Opuntia stricta

作者：Dengfeng Qi, Liangping Zou, Dengbo Zhou, Yufeng Chen, Zhufen Gao, Renjun Feng, Miaoyi Zhang, Kan Li, Jianghui Xie, Wei Wang · 发表于：Frontiers in Microbiology · 年份：2019 · DOI：10.3389/fmicb.2019.01390 · 被引用次数：123 · 研究领域：Microbial Natural Products and Biosynthesis、Plant Pathogens and Fungal Diseases、Mycorrhizal Fungi and Plant Interactions

Actinomycetes are important producers of antibiotics and other important bioactive substances. Extraordinary ecosystems cause the evolution of novel secondary metabolic pathways of Actinomycetes, and increase the discovery possibility of new biological functions of bioactive compounds. Here, we isolated a rare Actinomycete from the soil samples of Cactus rhizosphere. An antagonistic Actinomycete strain (named SCA3-4) was screened against Fusarium oxysporum f. sp. cubense Tropical Race 4 (Foc TR4, ATCC 76255). The strain produced Pink-white aerial mycelia and brown substrate mycelium on gause No. 1 agar. Biverticillate chains of cylindrical spores were detected by scanning electron microscope (SEC). Analysis of the 16S rRNA sequence and a phylogenetic tree exhibited that the SCA3-4 strain shared a 99.54% similarity with Streptoverticillium lilacinum NRRL B-1968T and clustered into the same branch. Based on morphological, biochemical, physiological and molecular characteristics, the SCA3-4 strain was identified as Streptoverticillium sp. It can grow well on the different antibiotic medium with chloramphenicol, streptomycin, penicilin-G, gentamicin, erythromycin or neomycin sulfate. The PCR amplification of type I and Ⅱ polyketide synthase genes (PKS-I and PKS-Ⅱ) supported that the SCA3-4 strain owned the possible antimicrobial activity. Ethyl acetate extracts of the SCA3-4 strain showed a broad-spectrum antifungal activity against 13 plant pathogenic fungi including Foc TR4 and...