Data_Sheet_1_Structure modification of an antibiotic: by engineering the fusaricidin bio-synthetase A in Paenibacillus polymyxa.docx

Fusaricidin, a lipopeptide antibiotic, is specifically produced by Paenibacillus polymyxa strains, which could strongly inhibit Fusarium species fungi. Fusaricidin bio-synthetase A (FusA) is composed of six modules and is essential for synthesizing the peptide moiety of fusaricidin. In this study, we confirmed the FusA of Paenibacillus polymyxa strain WLY78 involved in producing Fusaricidin LI-F07a. We constructed six engineered strains by deletion of each module within FusA from the genome of strain WLY78. One of the engineered strains is able to produce a novel compound that exhibits better antifungal activity than that of fusaricidin LI-F07a. This new compound, known as fusaricidin [ΔAla6] LI-F07a, has a molecular weight of 858. Our findings reveal that it exhibits a remarkable 1-fold increase in antifungal activity compared to previous fusaricidin, and the fermentation yield reaches ~55 mg/L. This research holds promising implications for plant protection against infections caused by Fusarium and Botrytis pathogen infection.</p

Colonization of the GFP-labeled <i>P</i>. <i>polymyxa</i> WLY78 in cucumber seedlings in the gnotobiotic system.

<p>(A-D) Colonization patterns after 1 day of inoculation. (E-H) Colonization patterns after 3–5 days of inoculation. (I-J) Colonization patterns of cucumber stems after 7 days of inoculation. (K-L) Colonization patterns of leaves after 10 days of inoculation.</p

Colonization of the GFP-labeled <i>P. polymyxa</i> WLY78 in wheat roots in the soil system.

<p><b>(A)</b> Colonization patterns after 3 days of inoculation. (B) Colonization patterns after 7 days of inoculation. (C-D) Colonization patterns after 10 days of inoculation.</p

Confocal image of the GFP-labeled <i>P</i>. <i>polymyxa</i> and colonization of the GFP-labeled cells in wheat roots in the gnotobiotic system.

<p>(A) Confocal image of the GFP-labeled <i>P</i>. <i>polymyxa</i> cells. (B-D) Colonization patterns of the GFP-labeled <i>P</i>. <i>polymyxa</i> WLY78 in wheat roots after 15 hours of inoculation. (E-G) Colonization patterns after 1 day of inoculation. (H) Colonization patterns after 3 days of inoculation. (I-J) Colonization patterns after 5 days of inoculation. (K) Colonization patterns after 7 days of inoculation. (L) Colonization patterns after 10 days of inoculation.</p

Colonization of the GFP-labeled <i>P</i>. <i>polymyxa</i> WLY78 in maize seedlings in the gnotobiotic system.

<p>(A-B) Colonization patterns after 1 day of inoculation. (C-D) Colonization patterns after 3 days of inoculation. (E-F) Colonization patterns after 5 days of inoculation. (G-H) Colonization patterns after 7 days of inoculation. (I-L) Colonization patterns after 10 days of inoculation.</p

Reducing carbon: phosphorus ratio can enhance microbial phytin mineralization and lessen competition with maize for phosphorus

<div><p>We tested the hypothesis that reducing the carbon (C):Phosphorus (P) ratio in rhizosphere soil would reduce bacterial competition with the plant for P from phytin, which would then increase phytin use efficiency for the plant. A three-factor pot experiment was carried out to study the effect of inoculation with a phytin-mineralizing bacterium, <i>Pseudomonas alcaligenes</i> (PA), on maize P uptake from phytin. Two levels of organic P, two levels of inorganic P, and three different PA inoculation treatments were used. When maize plants were grown in low available P soil with phytin, PA transformed soil P into microbial biomass P, which caused competition for available P with plant and inhibited plant uptake. When 5 mg P kg⁻¹ as KH₂PO₄ was added, inoculation with PA increased soil acid phosphatase activity which enhanced the mineralization rate of phytin. PA mobilized more P than it immobilized in microbial pool and enhanced plant P uptake. We conclude that the decreased C:P ratio by adding small amount of inorganic P in the rhizosphere could drive phytin mineralization by the bacteria and improve plant P nutrition.</p></div

<i>Paenibacillus</i> strains used in study.

<p><i>Paenibacillus</i> strains used in study.</p

Synteny of the chromosomal regions flanking the <i>nif</i> gene cluster among each sub-group.

<p>(A) <i>nif</i> clusters of Sub-group I. (B) The chromosomal regions of non-N₂-fixing strains corresponding to those flanking the <i>nif</i> gene cluster of Sub-group I. (C) <i>nif</i> clusters of Sub-group II.</p

Bayesian inferred phylogenetic tree of concatenated NifHDK homologs.

<p>The interior node values of the tree are clade credibility values, values lower than 100% are indicated. Branches are colored blue (Mo-nitrogenase, Nif), green (V-nitrogenase, Vnf), purple (Fe-nitrogenase, Anf), light blue (uncharacterized homolog), dark yellow (uncharacterized nitrogenase). The text colored red was <i>Paenibacillus</i>.</p

Genomic diversity of strains in the genus <i>Paenibacillus</i>.

<p>Each strain is represented by an oval that is colored: N₂-fixing strains (red), non- N₂-fixing strains (purple). The number of orthologous coding sequences (CDSs) shared by all strains (i.e., the core genome) is in the center. Overlapping regions show the number of CDSs conserved only within the specified genomes. Numbers in non-overlapping portions of each oval show the number of CDSs unique to each strain. The total number of protein coding genes within each genome is listed below the strain name.</p