Definition
Fictibacillus rigui is a bacterial species belonging to the genus Fictibacillus within the family Bacillaceae. It is classified as a Gram‑positive, rod‑shaped, spore‑forming microorganism.
Overview
The species was described following the isolation of a strain from a freshwater environment (river water) in South Korea. As a member of Fictibacillus, it shares the genus’s general traits of being aerobic, catalase‑positive and oxidase‑negative. The bacterium is mesophilic, exhibiting optimal growth at temperatures typical for moderate‑temperature aquatic habitats. Its discovery contributed to the expanding diversity of the Fictibacillus genus, which comprises several species isolated from various soil and water sources.
Etymology / Origin
The specific epithet rigui is derived from the Latin word rigus, meaning “stream” or “brook,” reflecting the aquatic origin of the type strain from which the species was first isolated.
Characteristics
- Cell morphology: Straight, rod‑shaped cells that are capable of forming endospores.
- Gram stain: Positive.
- Metabolism: Strictly aerobic; utilizes a range of carbohydrates as carbon and energy sources.
- Physiology: Catalase‑positive and oxidase‑negative; grows under mesophilic conditions (approximately 20–37 °C).
- Phylogeny: 16S rRNA gene sequence analysis places F. rigui within the Fictibacillus clade, showing closest similarity to other Fictibacillus species such as F. phosphorivorans and F. halophilus.
- Type strain: The type strain has been deposited in recognized microbial culture collections (e.g., KCTC and JCM) under accession numbers assigned in the original description. Detailed phenotypic and genotypic data are documented in the primary taxonomic publication.
Related Topics
- Genus Fictibacillus – a group of Gram‑positive, spore‑forming bacilli reclassified from the former Bacillus genus.
- Bacillaceae – the family encompassing Fictibacillus and related genera.
- Freshwater microbiology – study of microbial communities inhabiting rivers, lakes, and reservoirs.
- Taxonomic methods – use of 16S rRNA sequencing, phenotypic profiling, and chemotaxonomic analyses for bacterial classification.
Note: Specific numerical data (e.g., exact temperature optima, strain accession numbers) are omitted due to limited publicly available details in secondary sources.