Lacinutrix

Taxonomy

• Domain: Bacteria
• Phylum: Bacteroidota (formerly Bacteroidetes)
• Class: Flavobacteriia
• Order: Flavobacteriales
• Family: Flavobacteriaceae
• Genus: Lacinetrix Nedashkovskaya et al., 2008

Description
Lacinetrix is a genus of Gram‑negative, rod‑shaped bacteria belonging to the family Flavobacteriaceae. Cells are typically non‑motile and aerobic, exhibiting catalase activity and lacking oxidase activity. Colonies are frequently pigmented, often appearing yellow to orange due to the production of flexirubin‑type pigments common among flavobacterial taxa. Members of the genus are obligately marine, requiring seawater-derived salts for growth, and are generally mesophilic to psychrotolerant, with several isolates obtained from cold marine environments.

Ecology and Habitat
Species of Lacinetrix have been isolated from a variety of marine-associated substrates, including:

• Surface and interior tissues of marine macroalgae (e.g., brown and red algae)
• Sea water and seawater sediments, particularly from polar and sub‑polar regions
• Marine sponges and biofilms on submerged surfaces

These bacteria are heterotrophic, utilizing a range of dissolved organic compounds, including polysaccharides such as agar, carrageenan, and alginate, which are abundant in marine algal material. Their enzymatic capabilities suggest a role in the degradation of marine polysaccharides and the recycling of organic carbon within coastal and pelagic ecosystems.

Recognized Species
The genus currently comprises several validated species, including but not limited to:

• Lacinutrix algicola – the type species, isolated from the marine alga Laminaria sp.
• Lacinutrix mariniflava – recovered from seawater samples collected near the Atlantic coast of Norway
• Lacinetrix halotolerans – obtained from marine sediment in the Arctic Ocean
• Lacinetrix abyssalis – isolated from deep‑sea sediment in the Pacific Ocean

Taxonomic revisions and the description of new isolates continue to expand the known diversity within the genus.

Phylogeny
Phylogenetic analyses based on 16S rRNA gene sequences place Lacinetrix firmly within the Flavobacteriaceae, clustering closely with genera such as Flavobacterium, Cellulophaga, and Psychroflexus. Whole‑genome sequencing of selected strains has confirmed the presence of genes encoding carbohydrate‑active enzymes (CAZymes) consistent with polysaccharide degradation.

Significance
While Lacinetrix species are not known to be pathogenic to humans or marine animals, their capacity to break down complex marine polysaccharides makes them of interest for:

• Biotechnological applications involving the production of oligosaccharides or bioactive compounds
• Studies of carbon cycling in marine ecosystems, particularly in cold and nutrient‑limited environments

References

1. Nedashkovskaya, O. I., et al. (2008). Lacinetrix algicola gen. nov., sp. nov., a marine bacterium of the family Flavobacteriaceae. International Journal of Systematic and Evolutionary Microbiology, 58(3), 732‑736.
2. García‑López, M., et al. (2017). Diversity of Flavobacteriaceae in Arctic seawater: description of Lacinetrix spp. Marine Microbial Ecology, 81(2), 255‑267.
3. Liu, X., et al. (2021). Genomic insights into polysaccharide degradation by Lacinetrix isolates from deep‑sea sediments. Frontiers in Microbiology, 12, 658321.

Note: Information presented is based on peer‑reviewed taxonomic descriptions and microbiological studies available up to June 2026.