Dispersal strategies drive marine microbial diversity
Date:
March 15, 2022
Source:
eLife
Summary:
Trade-offs between the benefit of colonizing new particles and the
risk of being wiped out by predators allow diverse populations of
marine microbes to exist together, shows a new study.
FULL STORY ========================================================================== Trade-offs between the benefit of colonising new particles and the risk
of being wiped out by predators allow diverse populations of marine
microbes to exist together, shows a study published today in eLife.
==========================================================================
The findings help explain how a vast array of diverse bacteria and
microbes coexist on floating particle rafts in oceans.
Microbial foraging in patchy environments, where resources are fragmented
into particles, plays a key role in natural environments. In oceans and freshwater systems, bacteria and microbes can interact with particle
surfaces in different ways: some only colonise them for short periods,
while others form long-lived, stable colonies.
Scientists have long puzzled over the greater-than-expected diversity
of microscopic creatures in oceans, a phenomenon called the 'plankton
paradox'.
While researchers have begun to understand the factors that support so
many different types of plankton, many questions remain about the more plentiful ocean microbes that live on floating particles.
"We wanted to study the role that dispersal strategies play in the
successful coexistence of different microbes living on the same set of particles," says co-first author Ali Ebrahimi, who completed the study
while he was a postdoctoral fellow at the Ralph M. Parsons Laboratory
for Environmental Science and Engineering, Massachusetts Institute of Technology (MIT), Cambridge, US.
Ebrahimi and the team used mathematical modelling and computer simulations
to test how different dispersal strategies may help marine microbes
exist together in this way. They found that differently navigating the trade-offs between growth and survival can allow microbes to thrive
together.
Their model showed that organisms which stay put on a single particle for longer have more opportunities to multiply. However, they face a higher
risk of being wiped out by a virus or other predator capable of engulfing
whole particles. On the other hand, microbes that more frequently hop
between particles have less opportunity to multiply, but also have a
lower risk of facing a mass mortality event. The success of one strategy
over another may depend on differing environmental conditions.
"When the particle supply is high, microbes that hop rapidly between
them will have a greater chance of survival," explains co-first author
Akshit Goyal, Physics of Living Systems Fellow at the MIT Department of Physics. "But when particles are harder to come by, the bacteria that
stay put will have an advantage." Additionally, the team found that coexistence can remain stable in the face of changing environmental
conditions, such as algal blooms of particles, favouring growth, and
changing numbers of predators, favouring mortality. Together, these
differing factors significantly increase the likelihood that populations
with diverse dispersal strategies can live together.
"Our work focused on the link between dispersal and mortality in the
ocean, but there's plenty more going on in these environments," Goyal concludes. "Future research could provide important new insights on
how environmental changes might impact these minuscule communities and,
in turn, their wider marine ecosystem." Co-first authors Ebrahimi and
Goyal worked on this study alongside senior author Otto Cordero, Associate Professor at the MIT Department of Civil and Environmental Engineering.
========================================================================== Story Source: Materials provided by eLife. Note: Content may be edited
for style and length.
========================================================================== Journal Reference:
1. Ali Ebrahimi, Akshit Goyal, Otto X Cordero. Particle foraging
strategies
promote microbial diversity in marine environments. eLife, 2022;
11 DOI: 10.7554/eLife.73948 ==========================================================================
Link to news story:
https://www.sciencedaily.com/releases/2022/03/220315121440.htm
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