The antibacterial mechanism of phenylacetic acid isolated from Bacillus megaterium L2 against Agrobacterium tumefaciens

Abstract

Background Agrobacterium tumefaciens T-37 can infect grapes and other fruit trees and cause root cancer. Given the pollution and damage of chemical agents to the environment, the use of biological control has become an important area of focus. Bacillus megaterium L2 is a beneficial biocontrol strain isolated and identified in the laboratory, which has a good antibacterial effect on a variety of plant pathogens. The antibacterial metabolites of L2 were separated and purified to obtain a bioactive compound phenylacetic acid (PAA). Methods The potential antibacterial mechanism of PAA against A. tumefaciens T-37 strain was determined by relative conductivity, leakage of nucleic acids, proteins, and soluble total sugars, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and reactive oxygen species (ROS). Results PAA showed good antibacterial activity against strain A. tumefaciens T-37 with IC50 of 0.8038 mg/mL. Our data suggested that after treatment with PAA, the relative conductivity, nucleic acid, protein, and total soluble sugar of T-37 were increased significantly compared with the chloramphenicol treatment group and the negative treatment group. The total protein synthesis of T-37 cells was inhibited, the consumption of phosphorus decreased with the increase of incubation time, and the content of ROS was significantly higher than that in the negative treatment group. Meanwhile, the activity of two key enzymes (MDH and SDH) involved in the tricarboxylic acid cycle (TCA cycle) decreased. In addition, T-37 cells were found to be damaged by scanning electron microscopy observation. Our results showed that PAA can destroy cell membrane integrity, damage cell structures, affect cell metabolism, and inhibit protein synthesis to exert an antibacterial effect. Conclusions We concluded that the mechanism of action of the PAA against strain T-37 might be described as PAA exerting antibacterial activity by affecting cell metabolism, inhibiting protein synthesis, and destroying cell membrane integrity and cell ultrastructure. Therefore, PAA has a promising application prospect in the prevention and treatment of root cancer disease caused by A. tumefaciens.

Perception of the Biocontrol Potential and Palmitic Acid Biosynthesis Pathway of Bacillus subtilis H2 through Merging Genome Mining with Chemical Analysis

“…tumefaciens and E. carotovora pose serious threats to agricultural development. , The antibacterial activity results indicated that the inhibition zone of strain H2 against pathogenic bacteria T-37 and RF was significantly higher than that of the chloramphenicol control (Figure C). Furthermore, field experiments evaluating the control effect of rice blast demonstrated that the B.…”

“…Plant diseases caused by plant pathogenic bacteria have a significant impact on the sustainable development of agriculture, leading to substantial economic losses. 56,57 Notably, bacterial plant diseases caused by A. tumefaciens and E. carotovora pose serious threats to agricultural development. 56,58 The antibacterial activity results indicated that the inhibition zone of strain H2 against pathogenic bacteria T-37 and RF was significantly higher than that of the chloramphenicol control (Figure 1C).…”

“…56,57 Notably, bacterial plant diseases caused by A. tumefaciens and E. carotovora pose serious threats to agricultural development. 56,58 The antibacterial activity results indicated that the inhibition zone of strain H2 against pathogenic bacteria T-37 and RF was significantly higher than that of the chloramphenicol control (Figure 1C). Furthermore, field experiments evaluating the control effect of rice blast demonstrated that the B. subtilis H2 agent, at a concentration of 1 × 10 8 CFU/mL, significantly promoted rice growth and achieved a disease control effect of 70% (Table 2).…”

“…Microorganisms were the known source of new bioactive with different structures such as Bacillus , Pseudomonas , Streptomyces , and Chryseobacterium , which possess antimicrobial activity. , The results of the confrontation culture experiment demonstrated that strain H2 exhibited antimicrobial activity against both plant pathogenic fungi and bacteria (Figure A,B). Plant diseases caused by plant pathogenic bacteria have a significant impact on the sustainable development of agriculture, leading to substantial economic losses. , Notably, bacterial plant diseases caused by A. tumefaciens and E.…”

GC-MS Analysis, Antibiogram and Computational Studies of Kakamout (Acacia polyacantha L.) Leaves Hydro-Ethanolic Extract

“…Phenyl acetic acid as antibacterial compound [22]could possibly in a synergism act as antibacterial in the extract [23]. b Predicted aqueous solubility in mol/L (acceptable range -6.5-0.5).…”