Identification of antimicrobial metabolites produced by a potential biocontrol Actinomycete strain A217

Abstract

Aims To extract and identify the metabolites of strain A217 as well as its antifungal spectrum and control effect on various plant pathogens. Methods and Results Strain A217 was identified as a Streptomyces sp. which was most similar to Streptomyces lienomycini. An antimicrobial spectrum test indicated that strain A217 inhibited several plant pathogenic fungi and strong antibacterial effect such as Phytophthora capsici, Botrytis cinerea, Sclerotinia sclerotiorum, Fusarium oxysporum, Pseudomonas syringae and Xanthomonas campestris. An in vivo tissue test demonstrated that the fermentation broth of strain A217 exerted therapeutic and protective effects of 49·47 and 61·60% respectively, on S. sclerotiorum. Additionally, the fermentation broth of A217 exerted control effects on walnut black spot disease in walnut leaves and branches amounting to 79·33 and 81·52% respectively. In a pot experiment, the fermentation broth exhibited a stronger protective and control effect (68·29%), as well as better bacteriostatic and disease control effects on Phytophthora blight of pepper, compared with Metalaxyl. Compounds possessing antifungal and antibacterial activities were obtained from the fermentation broth of strain A217, using column chromatography and HPLC. Chemical and structural analyses conducted using MS and nuclear magnetic resonance confirmed that these compounds were 1H‐pyrrole‐2‐carboxylic acid and 1H‐pyrrole‐2‐carboxamide. The EC50 values of compound 1H‐pyrrole‐2‐carboxylic acid1 for S. sclerotiorum and P. capsici were 20·13 and 50·36 μg ml−1 respectively. Compound 1H‐pyrrole‐2‐carboxamide2 showed significant antibacterial activity against different plant pathogenic bacteria. The MIC values of P. syringae, X. campestris and X. campestris pv. jugiandis were 7·5, 30 and 15·0 μg ml−1 respectively. Conclusions Actinomyces A217 fermentation products have a broad spectrum of bacteriostasis, and have good bacteriostasis activity to many plant pathogenic fungi and bacteria. Significance and Impact of the Study The present study revealed a new antimicrobial producing strain of Streptomyces and its potential application as a biological control agent for plant diseases.

Bioassay-Guided Isolation of Broad-Spectrum Fungicidal Active Compound from Artemisia ordosica

“…Eleven pathogenic bacteria were used in this study, five of which were significantly inhibited in in vitro and in vivo assays ( Figure 7 ), including X. campestris pv. jugiandis (cause of black rot in walnut) [ 40 ]), E. carotovora subsp. carotovora (cause of soft rot in potatoes and vegetables) [ 41 , 42 ]), and P. syringae pv.…”

Antifungal mechanism of Streptomyces ma. FS‐4 on fusarium wilt of banana

“…This rapid generation of ROS is called an oxidative burst and provides extremely harsh environments for pathogens. He et al studied the mechanism of α-lycopene on fungal cell death induced by filamentous pathogenic fungus F. oxysporum and found that α-lycopene causes ROS outbreak and depolarization of mitochondrial membrane potential in F. oxysporum (He et al 2020).…”

“…2015), cellulose (Singh and Gaur 2016), nuclease (He et al . 2020) and so on. The cell wall of pathogenic bacteria is used for their own growth by breaking down nutrients that cause the death of pathogenic bacteria (Wang et al .…”

“…Streptomyces grow by attaching to and invading the mycelium of pathogenic bacteria, and release active substances to cause host granulation of the pathogenic bacteria and coagulation of protoplasts, eventually causing the mycelia of the pathogenic bacteria to dissolve (Alijani et al 2019). In addition, Streptomyces can secrete a variety of cell wall hydrolases, such as chitinase (Pageni et al 2014), glucanase (Passari et al 2015), cellulose (Singh and Gaur 2016), nuclease (He et al 2020) and so on. The cell wall of pathogenic bacteria is used for their own growth by breaking down nutrients that cause the death of pathogenic bacteria (Wang et al 2018).…”

Actinobactérias no controle do mal das folhas em mudas de seringueira

“…Estudos demonstraram o potencial das actinobactérias como agentes de controle biológico de fitopatógenos em culturas de interesse econômico (SOLTANZADEH et al, 2016;GOMES et al, 2018;HAO et al, 2020). As actinobactérias, particularmente o gênero Streptomyces, são reconhecidas pelo seu potencial em produzir uma vasta quantidade de metabólitos secundários, dentre os quais se destacam as substâncias antibióticas (ANZAI et al, 2008;BARRETO et al, 2008;DURAIPANDIYAN et al, 2010;MIYAUCHI, 2012).…”