To the Himalayan marmot and beyond: new microbes discovered this month

Posted on May 31, 2023   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.

IJSEM.png 1

The discovery of Cellulomonas xiejunii, Cellulomonas chengniuliangii and Cellulomonas wangsupingiae were published in International Journal of Systematic and Evolutionary Microbiology this month. While these bacteria are new to science, their source is not. You might be familiar with the Marmota himalayana, otherwise known as the Himalayan marmot, from a previous edition of ‘New to Science’. These three newly discovered microbes were also isolated from our furry friends, their intestinal contents to be exact, in Qinghai Province, PR China. Each new bacterial species is named after a professor at Shanxi Medical University in honour of their contributions to medicine. In fact, the Himalayan marmot is really carrying this edition of ‘New to Science’, as it is the source of two more novel microbes published this month. Nocardioides marmotae and Nocardioides faecalis were isolated from the faeces of M. himalayana during a study exploring the microbial diversity of Nocardioides on the Qinghai–Tibet Plateau.

Himalayan marmot RNMitra.jpg
© iStock/RNMitra

For our next new microbe we can move away from the Himalayan marmot and on to humans. Curtanaerobium respiraculi is a novel bacterium isolated from human bronchoalveolar lavage fluid. A bronchoalveolar lavage is a procedure where a small amount of saline is introduced to the lungs through a bronchoscope, before the lung fluid is then collected and tested. It was originally believed that the lungs were a sterile environment, but in recent years it has been proven that the lungs are a low-density diversified microbial ecosystem. Next generation sequencing technology has shown that the lung microbiome is dominated by the phyla Pseudomonadota, Bacillota, Bacteroidota and the phyla of our new bacterium Actinomycetota. Our new bacterium is not only a new species within this phyla, but also a new genus.

We need to look down to the soil for our next novel microbe. Massilia agrisoli was isolated from the rhizosphere of a banana plant in Dighalgram, Magura, Bangladesh. The plant rhizosphere bacterial community is a regular feature of ‘New to Science’ and is home to many of our newly discovered microbes. The rhizosphere is the soil surrounding the root of the plant that is affected by its biological activities and is home to a community of bacteria called a microbiome. Our newly discovered microbe joins the species Massilia, which has been found in an array of ecological niches, including human clinical specimens, drinking water and even ice cores. 

Keeping to the soil and moving back to China we find our final new microbes, Geothrix fuzhouensis and Geothrix paludis. These two anaerobic, Fe(III)-reducing and gram-negative strains were isolated from paddy soils in Fujian Province, PR China. Our new microbes were found during an investigation of the diversity analysis of Fe(III) reducing bacteria in paddy soil but iron reducing bacteria have been found in various other anaerobic environments including groundwater and lake sediments.