Unexpected host dependency of Antarctic Nanohaloarchaeota

Salt-loving symbionts of Antarctica

31 October 2019

Some of Antarctica’s apparently independent saltwater microbes rely on others to grow.

Nanohaloarchaea are microscopic relatives of the salt-loving, single-celled haloarchaea. They are thought to be independent organisms despite their reduced genome size.

Now, a team that included researchers from the University of New South Wales has extracted two species of nanohaloarchaea from two salty Antarctic lakes and cultivated them in the lab alongside other microbes native to these icy waters.

The team found that the nanohaloarchaea needs cell−cell contact with Halorubrum lacusprofundi, a haloarchaea found in one of Antarctica’s coldest lakes, to grow. They probed their protein interactions to discover how the nanohaloarchaea nabbed nutrients from its host.

An ability to grow and study nanohaloarchaea in the lab could improve understanding of microbial relationships that may be important to environmental processes in Antarctica.

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References

1. PNAS 116, 14661–14670 (2019). doi: 10.1073/pnas.1905179116