[6] They form circular cream to orange coloured colonies on agar, and are typically simple to successfully culture.

[5] Flavobacteriia is a chemoorganotroph and are known for their ability to mineralize or degrade dissolved organic matter of high molecular weight and particulate plant material.

[12] Recent taxonomic updates have reclassified several Flavobacterium species to new genera such as Microbacterium, Salegentibacter, and Planococcus.

[16][4] Flavobacteriia used to contain many non-related species of yellow, rod-shaped bacteria, but taxonomy has changed and stabilized due to the sequencing of rRNA to deduce phylogenetic relationships.

[9] Flavobacteriia can also be found in non-marine systems and are most common in Asian regions, specifically Korea and China, as well as Japan and India.

[13] Flavobacteriia are a type of gram-negative rod-shaped bacteria with sizes typically ranging from 0.1μm to 0.5μm wide and 2μm to 5μm long.

[22] They are classified as gram-negative due to the composition of their cell wall, which consists of a thin layer of peptidoglycan surrounded by an outer membrane composed of lipopolysaccharides.

[8] These colonies typically appear slightly translucent and can range in colour from pale yellow/cream to orange due to the presence of pigments such as carotenoids or flexirubin.

[25][26] Flavobacteriia exhibit a predominant forward gliding motion, but can also reverse direction and show flipping movements .

[8] Some species of Flavobacteriia have the ability to use a broad range of carbohydrates as energy sources, while others have a limited capacity or none at all, and instead prefer to utilize amino acids and proteins.

[8] Approximately half of the species belonging to Flavobacteriia are capable of breaking down carbohydrates into acid and can degrade tyrosine and tween compounds.

[8] Many species also play a significant role in the mineralization of organic matter in both aquatic and soil environments due to their capability of breaking down various types of biomacromolecules.

Techniques vary by species due to the high diversity of the class, however many are cultivated on simple media using yeast extract and a protein hydrolysate.

Columnaris disease causes skin lesions, fin erosion, and gill necrosis, leading to mortality.

[9] In the early stage of marine biofilms formation, Flavobacteriia colonize and form microcolonies to serve as a foundation for establishing other microorganisms in a community.

In the biofilms community, Flavobacteriia also engage in a variety of cooperated interactions with other microbes rather than competition, including quorum sensing, nutrient sharing and scavenging.

[13] Due to the formation of metabolic byproducts, spoilage of uncooked red flesh causes unpleasant smells, potential slime production, localised discolouration and unwanted flavours.

Similarly, while Flavobacteriia are a continuous component of the initial flora in cold meats and fowl, they are unable to outcompete pseudomonads during preservation.

[13] Flavobacteriia create pasteurisation-resistant extracellular enzymes, which causes the psychrotrophic deterioration of milk and dairy products.

In adults, infections can manifest in a variety of ways, including pneumonia, sepsis, meningitis, endocarditis, post-surgery, and post-burn.

[31] To this point, existing pathogenic Flavobacteriia are currently very rare and difficult to detect, but remain a concern because they are resistant to many antimicrobial drugs.