Biological control of plant pathogens by Bacillus species
Biological control of plant pathogens by Bacillus species
复制标题
DOI：
10.1016/j.jbiotec.2018.07.044
复制
发表时间：
2018-11-10
影响因子：
4.1
通讯作者：
Stankovic, Slavisa
中科院分区：
文献类型：
--
作者：
Fira, Djordje;Dimkic, Ivica;Stankovic, Slavisa
来自芽孢杆菌属的细菌是栖息在大量不同栖息地的微生物。众所周知，它们是各种不同结构的拮抗化合物的生产者，具有5至8%的总基因组致力于次生代谢物的生物合成。芽孢杆菌属的最重要的生物活性分子是非核糖体合成的肽和脂肽、聚酮化合物、细菌素和铁载体。来自芽孢杆菌属的脂肽具有非常复杂的由非核糖体肽合成酶（NRPS）催化的生物合成机制，非核糖体肽合成酶是具有模块结构的大酶复合物，每个模块负责掺入特定的氨基酸。一般而言，它们对植物病原细菌、真菌和病毒具有广谱拮抗活性。来自这一组的最重要的分子，来自surfactin、iturin和fengycin家族的环状脂肽在膜水平上影响靶细胞。芽孢杆菌属菌株主要通过抑制植物病原菌的生长、诱导植物的系统抗性以及与植物病原菌竞争生态位来表现其生防能力。我们以前的研究表明，存在多个生物合成操纵子合成的非核糖体脂肽的天然分离物的芽孢杆菌的集合，与许多菌株有一个以上的。我们最近鉴定的几种芽孢杆菌菌株对植物病原体表现出非常强的抗细菌和抗真菌活性。PCR分析表明，存在的生物合成操纵子的伊枯草菌素，芽孢杆菌霉素，丰霉素和表面活性素在测试菌株。抗微生物物质生产动力学的测量表明，在大多数情况下，合成开始于指数生长期的开始，在稳定生长期开始时达到最大抗微生物活性，并在整个观察期内保持在该水平。测试菌株的无细胞上清液的制备物在体外和体内对许多真菌和细菌病原体具有活性。纯化化合物的质谱和HPTLC生物自显影分析证实了所述家族的脂肽的存在，因此证实了芽孢杆菌属分离物的生物防治能力。
Bacteria from the Bacillus group are microorganisms that inhabit a large number of different habitats. They are well known as producers of a wide array of antagonistic compounds of different structures, having between 5 to 8% of the total genome devoted to biosynthesis of secondary metabolites. Most important bioactive molecules from the genus Bacillus are non-ribosomally synthesized peptides and lipopeptides, polyketide compounds, bacteriocins and siderophores. Lipopeptides from Bacillus have very complex mechanisms of biosynthesis catalyzed by non-ribosomal peptide synthetases (NRPSs), large enzyme complexes with modular structure, with each module being in charge for the incorporation of a particular amino acid. In general, they have a broad spectrum of antagonistic activity against plant pathogenic bacteria, fungi and viruses. Most important molecules from this group, circular lipopeptides from surfactin, iturin and fengycin families affect the target cells on the membrane level. Bacillus strains exhibit their biocontrol capacity predominantly through inhibitory activity on the growth of plant pathogens, as well as inducing systemic resistance in plants and competing for ecological niches with plant pathogens. Our previous studies showed the presence of multiple biosynthetic operons for synthesis of non-ribosomal lipopeptides in the collection of natural isolates of Bacillus, with many strains having more than one of them. Several strains of Bacillus sp. that we have recently characterized showed very strong antibacterial and antifungal activity against phytopathogens. The PCR analysis showed the presence of biosynthetic operons for iturin, bacillomycin, fengycin and surfactin in tested strains. Measurement of the kinetics of production of antimicrobial substances showed that, in most cases, synthesis started at the beginning of exponential phase of growth, reaching the maximum of antimicrobial activity at the beginning of the stationary growth phase and stayed at this level for the whole duration of observed period. Preparations of cell-free supernatants of tested strains were active against many fungal and bacterial pathogens, in vitro and in vivo. Mass spectrometry and HPTLC bioautography analysis of purified compounds confirmed the presence of lipopeptides of mentioned families, hence confirming the biocontrol capacity of Bacillus isolates.