The application of Bacillus amyloliquefaciens in agriculture is wide. It has the function of increasing crop yield and inhibiting the growth of plant pathogens and nematodes. It can be colonized around plant roots to produce Surfactin, Bacillomycin D, Fengycin, Iturin, Amylocyclicin, and other antibacterial substances and induce plant system resistance.
It has a strong inhibitory effect on pathogenic bacteria such as Botrytis cinerea, Fusarium, Sclerotinia, Rhizoctonia, Streptomyces scab, Lauerella. It can be used for the prevention and control of various crops and has a good control effect.
At the same time, Bacillus amyloliquefaciens can produce gibberellin, indole acetic acid, cytokinin, abscisic acid, and other physiologically active substances and amino acids to reduce plant diseases and improve disease resistance, Promote crop growth, increase crop yield and improve quality.
Antibacterial Mechanism of Bacillus Amyloliquefaciens
1. Production of antibacterial substances
In Bacillus amyloliquefaciens, more and more substances that can inhibit the growth of pathogenic bacteria have been discovered and separated from the fermentation. According to their molecular weight, they are mainly divided into two categories, namely macromolecular antibacterial proteins and small molecule antibacterial peptides. Antibacterial peptides such as Surfactin, Fengucin, Iturin, etc.
Antibacterial proteins can degrade the hyphae of pathogenic fungi and inhibit the germination of pathogenic fungi conidia. The antibacterial protein can inhibit various fruit and vegetable disease pathogens such as loquat scorch rot, litchi scorch, olive scorch, and other fruit and vegetable disease pathogens, and has a good broad spectrum.
3. Induce resistance
The disease-prevention mechanism of Bacillus amyloliquefaciens mainly involves a series of enzymes such as phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO), peroxidase (POD), superoxide dismutase (SOD), etc. The activity changes, through the lignification of tissues, the production of phytoalexins, and the enhancement of the mechanical strength of the cells, they work together to resist viruses, bacteria, and fungi, thereby improving the host’s disease resistance.
4. Competition in space and nutrients
It can not only colonize the roots of wheat but also migrate to the stem and leaf organs of wheat to play a certain role in disease prevention. Bacillus amyloliquefaciens can rapidly multiply on the surface of loquat fruit, occupy part of the site, and by intertwining with its hyphae, secrete specific antibiotics, or affect the formation of sclerotia, thereby inhibiting the growth of mold hyphae.
Bacillus amyloliquefaciens can not only compete with other microorganisms for living space, but also regulate plant growth, induce plant system resistance, and inhibit the growth of plant pathogenic bacteria. Therefore, it is often used in the development of microbial fertilizers, seed treatment agents, fungicides, and preservatives. It plays an important role in modern agriculture, especially organic agriculture.