Summary auto-generated
Researchers isolated six novel bacterial strains from soil enriched on acetylated starch plastic, a biodegradable synthetic material. These Gram-negative, motile rods produced deep-yellow pigmentation and demonstrated the ability to partially depolymerize acetylated starch, as evidenced by clear zones around cell colonies when stained with iodine. The strains showed unique fatty acid profiles consisting almost entirely of branched fatty acids and were oxidase- and catalase-positive but did not ferment sugars. Phylogenetic analysis using 16S rRNA gene sequencing revealed the strains were most similar to Rhodanobacter lindaniclasticus (96.7% similarity) and Frateuria aurantia (96.0% similarity), but sufficiently distinct to warrant classification as a new genus and species. DNA-DNA hybridization and genetic fingerprinting analysis revealed two distinct genomic groups with 93% reassociation to each other and less than 10% to F. aurantia. The strains' higher DNA G+C content (71.5-71.9 mol%) and distinct phenotypic characteristics differentiated them from related species. The authors propose the new genus Fulvimonas with the single species Fulvimonas soli, with type strain LMG 19981T.
Key findings
- Six novel Gram-negative bacterial strains capable of partially degrading acetylated starch plastic were isolated from soil through enrichment culture.
- Fulvimonas soli strains possess unique branched fatty acid profiles (>90% branched fatty acids) and produce characteristic deep-yellow pigmentation.
- 16S rRNA sequencing showed 96.7% similarity to Rhodanobacter lindaniclasticus and 96% to Frateuria aurantia, but DNA-DNA hybridization confirmed they represent a distinct species with <10% reassociation to F. aurantia.
- The new genus Fulvimonas differs phenotypically from related species by being oxidase-positive, non-fermentative, motile, and capable of starch degradation but not lindane degradation.
This summary was generated automatically from the article PDF and is not part of the original publication. Refer to the PDF for the authoritative text.
Abstract
Six deep-yellow-pigmented strains were isolated from soil after enrichment on plasticized acetylated starch granules as a source of carbon. They showed very similar and unique fatty acid profiles, consisting almost exclusively of branched fatty acids. The strains consisted of small, motile rods, were oxidase- and catalase-positive, did not ferment sugars and were able to depolymerize starch and suspended acetylated starch in overlayer plates. The 16S rDNA sequence of a representative strain, strain LMG 19981(T), showed 96.7% sequence similarity to that of Rhodanobacter lindaniclasticus, 96.0% to that of Frateuria aurantia and less than 92% to sequences of other members of the gamma-Proteobacteria. Repetitive extragenic palindromic DNA PCR fingerprinting revealed two groups, representatives of which showed 93% DNA--DNA reassociation with each other and less than 10% with Frateuria aurantia LMG 1558(T). On the basis of phenotypic characteristics and the G+C content of the DNA, the strains could be differentiated from Frateuria aurantia and Rhodanobacter lindaniclasticus. The name Fulvimonas soli gen. nov., sp. nov. is proposed, with the type strain LMG 19981(T) (=DSM 14263(T)).