Scientists Uncover Rare Pink Bacteria That Photosynthesizes Without Oxygen

Scientists have discovered a new type of marine bacteria, Algirhabdus cladophorae, in Peter the Great Bay. The organism belongs to a rare group that uses sunlight for energy without producing oxygen. Its unique traits have already expanded our knowledge of ocean microbiology. The bacterium stands out as an aerobic anoxygenic phototroph. Unlike typical plants or algae, it harnesses light but releases no oxygen. Its cells are rod-shaped and grow into distinctive pink colonies.

Genetic analysis revealed another unusual feature: the machinery for its light-dependent metabolism sits on a separate plasmid. This circular DNA fragment spans 53,000 base pairs, rather than being embedded in the main genome. Researchers have classified *A. cladophorae* as its own genus within the *Roseobacteriaceae* family. The strain thrives in nutrient-poor waters thanks to its specialised photosynthesis. It has been preserved in international microorganism collections for further study. Scientists note that its discovery highlights previously unknown symbiotic networks in marine ecosystems.

Algirhabdus cladophorae now offers a clearer picture of how diverse marine microbes adapt to harsh environments. Its oxygen-free photosynthesis and plasmid-based genetic setup provide new research avenues. The findings also underscore the complexity of life in the ocean's low-nutrient zones.