New species found in the most unexpected places
Posted on March 7, 2025 by Clare Baker
Each month, the Microbiology Society publishes the International Journal of Systematic and Evolutionary Microbiology, which details newly discovered species of bacteria, fungi and protists. Here are some of the new species that have been discovered and the places they've been found.
Our first novel microbe attracted a bit of attention this month. It’s a bacterium belonging to a large group of bacteria that parasitize archaea. Minisyncoccus archaeiphilus was isolated from mesophilic methanogenic sludge and was found to inhibit the growth of the methanogenic archaeon Methanospirillum hungatei. M. hungatei plays a central role in anaerobic wastewater treatment systems. This is the first time researchers have successfully cultivated this type of bacteria, and they did so in a two-strain co-culture with the host archaeon where our bacteria strictly depended on M. hungatei as a host.
Next up are three novel species of Streptococcus that were isolated from human breast milk. Streptococcus wuxiensis, Streptococcus jiangnanensis and Streptococcus fermentans are coccoid-shaped strains that possessed extensive capabilities for carbohydrate metabolism, particularly human milk oligosaccharides utilization. Regular readers of ‘New to Science’ will recall this is not the first feature of a Streptococcus bacteria isolated from breastmilk as Streptococcus hohhotensis was included back in June.
Meanwhile, in Shanghai, China researchers got more than they bargained for after purchasing some Chinese pickled potherb mustard from a local market. They chopped up the condiment into pieces, soaked it in saline, diluted it and spread it on agar and isolated a novel bacterium Lacrimispora sinapis. The bacterium was rod-shaped, Gram-stain-positive and could grow at a wide range of temperatures (20–45 °C) and pH values (6.0–8.0). The bacterium was named Sinapis after the genus of flowering plants that includes mustard.
Talking of pickles, a new bacterium was isolated from a sea cucumber in research published this month. Pseudoalteromonas holothuriae was isolated from the coelomic fluid of our sea cucumber, Holothuria forskali, collected in the Glénan archipelago (Brittany, France). The coelomic fluid is the internal circulatory system of the sea cucumber and is found in the coelomic cavity. It comprises of immune cells, mediates the immune response and is not directly connected to the surrounding seawater.
We started this edition with wastewater treatment systems, let’s finish with a microbe found in one. Antrihabitans spumae is a novel bacterium isolated from stable foams formed in a wastewater treatment plant in New South Wales, Australia. Stable foams are persistent foams found in wastewater treatment plants that can be formed by various factors including excessive amounts of fats oil and grease, or the growth of foam forming filamentous bacteria[1]. The isolated strains showed a wide metabolic versatility, like enhanced membrane transport systems for amino acids, metals and phosphate, as well as the ability to synthesize mycolic acids, contributing to their hydrophobic nature and involvement in foam stabilization. Researchers think that these adaptations could have provided an advantage in wastewater treatment plants, where they persist in nutrient-rich, metal-laden and foam-stabilizing environments.