Potential of Burkholderia sp. IMCC1007 as a biodetoxification agent in mycotoxin biotransformation evaluated by mass spectrometry and phytotoxicity analysis.

Microbial degradation is considered as an attractive method to eliminate exposure to mycotoxin that cause a serious threat in agriculture global industry and severe human health problems. Compared with other more prominent mycotoxin compounds, fusaric acid (FA) biodegradation has not been widely investigated. In this study, a fusaric acid-degrading bacterium Burkholderia sp. IMCC1007 was identified by 16 S rRNA gene sequencing and its detoxification characteristics were evaluated. This strain able to utilize FA as sole energy and carbon source with growth rate (µ) of 0.18 h- 1. Approximately 93% from the initial substrate FA concentration was almost degraded to the residual about 4.87 mg L- 1 after 12 h of incubation. The optimal degradation conditions for pH and temperature were recorded at 6.0 with 30 °C respectively. An efficient FA degradation of strain IMCC1007 suggested its potential significance to detoxification development. Accroding to LC-MS/Q-TOF analysis, FA was bio-transformed to 4-hydroxybenzoic acid (C7H6O3) and other possible metabolites. Plant treated with detoxified FA products exhibited reduction of wilting index, mitigating against FA phytoxicity effect on plant growth and photosynthesis activity. Phytotoxicity bioassay suggested that degradation product of IMCC1007 was not a potent harmful compound towards plants as compared to the parent compound, FA. As a conslusion, our study provides a new insight into the practical application of biodetoxifcation agent in controlling mycotoxin contamination.

Mohd Din ARJ ，Shadan NH ，Rosli MA ，Musa NF ，Othman NZ ... -  《-》

A novel Burkholderia ambifaria strain able to degrade the mycotoxin fusaric acid and to inhibit Fusarium spp. growth.

Fusaric acid (FA) is a fungal metabolite produced by several Fusarium species responsible for wilts and root rot diseases of a great variety of plants. Bacillus spp. and Pseudomonas spp. have been considered as promising biocontrol agents against phytopathogenic Fusarium spp., however it has been demonstrated that FA negatively affects growth and production of some antibiotics in these bacteria. Thus, the capability to degrade FA would be a desirable characteristic in bacterial biocontrol agents of Fusarium wilt. Taking this into account, bacteria isolated from the rhizosphere of barley were screened for their ability to use FA as sole carbon and energy source. One strain that fulfilled this requirement was identified according to sequence analysis of 16S rRNA, gyrB and recA genes as Burkholderia ambifaria. This strain, designated T16, was able to grow with FA as sole carbon, nitrogen and energy source and also showed the ability to detoxify FA in barley seedlings. This bacterium also exhibited higher growth rate, higher cell densities, longer survival, higher levels of indole-3-acetic acid (IAA) production, enhanced biofilm formation and increased resistance to different antibiotics when cultivated in Luria Bertani medium at pH 5.3 compared to pH 7.3. Furthermore, B. ambifaria T16 showed distinctive plant growth-promoting features, such as siderophore production, phosphate-solubilization, 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, in vitro antagonism against Fusarium spp. and improvement of grain yield when inoculated to barley plants grown under greenhouse conditions. This strain might serve as a new source of metabolites or genes for the development of novel FA-detoxification systems.

Simonetti E ，Roberts IN ，Montecchia MS ，Gutierrez-Boem FH ，Gomez FM ，Ruiz JA ... -  《-》

Genome sequence data of Burkholderia sp. IMCC1007 isolated from maize rhizosphere: A potential strain in fusaric acid mycotoxin biodegradation.

Burkholderia sp. IMCC1007 is a gram-negative, aerobic bacterium affiliated with class Betaproteobacteria, which was successfully isolated from maize rhizospheric soil sample in UTM research plot, Pagoh, Malaysia by using enrichment method. Strain IMCC1007 utilized 50 mgL-1 fusaric acid as its carbon source and degraded it completely within 14 h. Genome sequencing was performed using Illumina NovaSeq platform. The assembled genome was annotated using RAST (Rapid Annotation Subsystem Technology) server. The genome size was approximately 8,568,405 base pairs (bp) in 147 contigs with a G+C content of 66.04%. The genome includes 8,733 coding sequences and 68 RNAs. The genome sequence has been deposited at GenBank with the accession number of JAPVQY000000000. In the pairwise genome-to-genome comparisons, the strain IMCC1007 had an average nucleotide identity (ANI) of 91.9% and digital DNA-DNA hybridization (dDDH) value of 55.2% with Burkholderia anthina DSM 16086T respectively. Interestingly, fusaric acid resistance gene (fusC) and nicABCDFXT gene clusters (hydroxylation of pyridine compound) were found in the genome. Additionally, preliminary genome annotation analysis of strain IMCC1007 identified tryptophan halogenase (prnA) gene responsible for antifungal pyrrolnitrin biosynthesis. This dataset herein provides further insights into the fusaric acid degradation mechanism of the genus Burkholderia.

Mohd Din ARJ ，Othman NZ 《Data in Brief》

Genetic dissection of the degradation pathways for the mycotoxin fusaric acid in Burkholderia ambifaria T16.

Vinacour M ，Moiana M ，Forné I ，Jung K ，Bertea M ，Calero Valdayo PM ，Nikel PI ，Imhof A ，Palumbo MC ，Fernández Do Porto D ，Ruiz JA ... -  《-》

Genome mining of Burkholderia ambifaria strain T16, a rhizobacterium able to produce antimicrobial compounds and degrade the mycotoxin fusaric acid.

Burkholderia ambifaria T16 is a bacterium isolated from the rhizosphere of barley plants that showed a remarkable antifungal activity. This strain was also able to degrade fusaric acid (5-Butylpyridine-2-carboxylic acid) and detoxify this mycotoxin in inoculated barley seedlings. Genes and enzymes responsible for fusaric acid degradation have an important biotechnological potential in the control of fungal diseases caused by fusaric acid producers, or in the biodegradation/bio catalysis processes of pyridine derivatives. In this study, the complete genome of B. ambifaria T16 was sequenced and analyzed to identify genes involved in survival and competition in the rhizosphere, plant growth promotion, fungal growth inhibition, and degradation of aromatic compounds. The genomic analysis revealed the presence of several operons for the biosynthesis of antimicrobial compounds, such as pyrrolnitrin, ornibactin, occidiofungin and the membrane-associated AFC-BC11. These compounds were also detected in bacterial culture supernatants by mass spectrometry analysis. In addition, this strain has multiple genes contributing to its plant growth-promoting profile, including those for acetoin, 2,3-butanediol and indole-3-acetic acid production, siderophores biosynthesis, and solubilisation of organic and inorganic phosphate. A pan-genomic analysis demonstrated that the genome of strain T16 possesses large gene clusters that are absent in the genomes of B. ambifaria reference strains. According to predictions, most of these clusters would be involved in aromatic compounds degradation. One genomic region, encoding flavin-dependent monooxygenases of unknown function, is proposed as a candidate responsible for fusaric acid degradation.

Alvarez F ，Simonetti E ，Draghi WO ，Vinacour M ，Palumbo MC ，Do Porto DF ，Montecchia MS ，Roberts IN ，Ruiz JA ... -  《-》