Switching up: Marine bacteria shift between lifestyles to get the best resources

September 25, 2020

Tsukuba, Japan - To stay, or not to stay? When it comes to nutrient resource patches, researchers from Japan and Switzerland have discovered that marine bacteria have a knack for exploiting them efficiently, timing movements between patches to get the best resources.

In a study published this month in Proceedings of the National Academy of Sciences, U.S.A., researchers from the University of Tsukuba and ETH Zurich have revealed that marine bacteria optimize nutrient uptake by switching between dispersal and resource exploitation.

Heterotrophic bacteria (i.e., those that cannot produce their own food, instead obtaining nutrition from other sources of organic carbon, such as plant or animal matter) are the main recyclers of dissolved organic matter (DOM) in the ocean. Hotspots of DOM that are made up of particles, such as marine snow, are important to the global carbon cycle.

"Some groups of heterotrophic bacteria take advantage of these hotspots," says one of the lead authors of the study Assistant Professor Yutaka Yawata. "We used bacteria from one of these groups to look at whether optimal foraging theory is applicable to microbes, because their influence on the global carbon cycle ultimately depends on bacteria's ability to find and obtain nutrients from particles. Borrowing from the field of behavioral ecology, we referred to this process as foraging."

The researchers examined microbial foraging by studying the behavior of marine bacteria in seascapes of organic particles. They conducted experiments using single-cell tracking, where bacteria were video-recorded and the number of bacteria and the amount of time they spent on a surface was extracted and modelled.

"We found that foraging marine bacteria optimize nutrient uptake by rapidly switching between attached and planktonic lifestyles, and fine-tune the time spent on particles according to patch quality," explains Assistant Professor Yawata. "Bacteria stay longer on particles of higher quality, as predicted by patch use theory."

Patch use theory, which is part of optimal foraging theory, predicts that organisms foraging in a mixed-resource environment balance the time spent on a patch that yields diminishing returns with the costs of leaving that patch to find a fresh one. Until this study, the applicability of optimal foraging theory to microorganisms has been largely unknown.

Optimal foraging theory--and specifically patch use theory--provides a valuable framework for understanding microorganisms and their effects on ecosystems, such as quantifying and predicting the role of marine bacteria in the uptake and cycling of ocean nutrients.
The article, "Constrained optimal foraging by marine bacterioplankton on particulate organic matter," was published in Proceedings of the National Academy of Sciences, U.S.A. at DOI: 10.1073/pnas.2012443117

University of Tsukuba

Related Bacteria Articles from Brightsurf:

Siblings can also differ from one another in bacteria
A research team from the University of Tübingen and the German Center for Infection Research (DZIF) is investigating how pathogens influence the immune response of their host with genetic variation.

How bacteria fertilize soya
Soya and clover have their very own fertiliser factories in their roots, where bacteria manufacture ammonium, which is crucial for plant growth.

Bacteria might help other bacteria to tolerate antibiotics better
A new paper by the Dynamical Systems Biology lab at UPF shows that the response by bacteria to antibiotics may depend on other species of bacteria they live with, in such a way that some bacteria may make others more tolerant to antibiotics.

Two-faced bacteria
The gut microbiome, which is a collection of numerous beneficial bacteria species, is key to our overall well-being and good health.

Microcensus in bacteria
Bacillus subtilis can determine proportions of different groups within a mixed population.

Right beneath the skin we all have the same bacteria
In the dermis skin layer, the same bacteria are found across age and gender.

Bacteria must be 'stressed out' to divide
Bacterial cell division is controlled by both enzymatic activity and mechanical forces, which work together to control its timing and location, a new study from EPFL finds.

How bees live with bacteria
More than 90 percent of all bee species are not organized in colonies, but fight their way through life alone.

The bacteria building your baby
Australian researchers have laid to rest a longstanding controversy: is the womb sterile?

Hopping bacteria
Scientists have long known that key models of bacterial movement in real-world conditions are flawed.

Read More: Bacteria News and Bacteria Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.