Dyadobacter endophyticus sp. nov., an endophytic bacterium isolated from maize root

Area of Science:

• Microbiology
• Bacteriology
• Plant-microbe interactions

Background:

• The genus Dyadobacter comprises Gram-negative, aerobic bacteria.
• Bacterial endophytes play crucial roles in plant health and development.
• Understanding novel bacterial species aids in characterizing plant-associated microbiomes.

Purpose of the Study:

• To taxonomically characterize a novel bacterial isolate from maize root tissue.
• To determine the phylogenetic and genotypic relationship of the isolate to known Dyadobacter species.
• To propose a new species designation based on polyphasic taxonomic data.

Main Methods:

• Isolation and cultivation of bacteria from surface-sterilized maize root tissue.
• Phylogenetic analysis using 16S rRNA gene sequences.
• DNA-DNA hybridization for genotypic relatedness assessment.
• Analysis of cellular fatty acid composition and polar lipid profiles.
• Determination of DNA G+C content.

Main Results:

• A novel Gram-negative, aerobic, rod-shaped bacterium, strain 65T, was isolated.
• Phylogenetic analysis placed strain 65T within the genus Dyadobacter, with high 16S rRNA gene similarity to D. jiangsuensis.
• Low DNA-DNA relatedness values confirmed strain 65T as distinct from related species.
• Distinct fatty acid profiles and polar lipid patterns differentiated strain 65T phenotypically.
• The DNA G+C content was determined to be 46.6 mol%.

Conclusions:

• Strain 65T represents a novel species within the genus Dyadobacter.
• The proposed name for the new species is Dyadobacter endophyticus sp. nov.
• The type strain is 65T (=CGMCC 1.15288T=DSM 100786T).
• This discovery expands the known diversity of endophytic bacteria associated with maize.