The first New to Science of 2025
Posted on January 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.
Happy New Year and welcome back to the first ‘New to Science’ of 2025.
Let’s start with a location that made a few appearances in ‘New to Science’ last year, Antarctica. This time, we’re visiting Potter Cove on King George Island to locate a new species, Bacteriovorax antarcticus. Something that is not a regular feature of ‘New to Science’, is the fact that our novel microbe is a bacterial predator. B. antarcticus belongs to a group called ‘Bdellovibrio and like organisms’ (BALOs), Gram-negative bacteria that selectively target other Gram-negative bacteria. To give you an idea of how this works, let’s take a look at the model organism of the group, Bdellovibrio bacteriovorus. In the attack phase, motile B. bacteriovorus cells locate and infiltrate their target bacterium. They enter the prey’s periplasmic space, transition into a growth phase and degrade the hosts cellular components to sustain replication. This eventually causes the membrane of the host cell to break down, killing the bacterium. The process then starts all over again as the predatory bacterial cells are released, ready to target a new, unfortunate, bacterium. BALOs are currently underrepresented in the current taxonomic frameworks, so the description of our novel predatory bacterial species holds significant value.
After that whirlwind story of predator and prey, let’s take a step back to some peace and quiet and into a cave. In the past decade, microbiologists have started to explore the interesting and diverse microbes found in caves as they are environments that are rarely visited by humans and could contain new taxa. It turns out microbiologists were right, as three new microbes, Streptomyces cavernicola, Streptomyces solicavernae and Streptomyces luteolus were found in soil samples taken from Phu Pha Phet Cave, Thailand. They join the genus Streptomyces and the phylum Actinomycetota. Actinobacteria are responsible for producing about two-thirds of all known antibiotics currently available on the market, and a significant number of these antibiotics are derived from members of the Streptomyces genus. The potential of our new discoveries doesn’t stop there, as other actinobacterial genera have been identified as producers of a wide range of biologically active compounds. Could our new bacteria turn out to have antifungal, anticancer or antibacterial properties perhaps?
We always enjoy bringing an archaeon into the mix in ‘New to Science’, so let’s take a look at Methanochimaera problematica, a novel hydrogenotrophic methanoarchaeon. It was isolated from cold seep sediment of Four-Way Closure Ridge, offshore southwestern Taiwan. A simple swab is probably too boring for this methanoarchaeon, as the sample containing M. problematica was collected by a TV-guided grabber along with benthic macrofauna community at a depth of 1357 m below sea level — pretty exciting right?
Still keeping away from the familiarity of bacteria, our next microbe is a novel cellulase-producing black yeast-like fungi called Exophiala zingiberis. This fungus was isolated from the tuber of a ginger plant from India. The genus Exophiala is commonly referred to as black yeasts or black yeast-like fungi due to dark pigmentation of their colonies.
Finally, our last novel microbe of this edition of ‘New to Science’ was isolated from muskmelon and watermelon seedlings affected by stem rot and wilting in Serbia. When tested, researchers discovered that our new microbe could cause severe disease in watermelon and squash seedlings in greenhouse conditions. How about a guessing game to work out this microbe’s name? This microbe belongs to the largest genus of all Gram-negative bacteria, which, as of now, contains 330 species and is rapidly growing. It also earned its species name from the location in which it was found. If you guessed Pseudomonas serbiensis you’d be right!