permaculture

[Lawrence London <lfljvenaura@gmail.com>]

Marine cyanobacteria create microscopic ‘meals on wheels’

Researchers find the first widespread evidence of vesicles in ocean life

Marine scientists at the National Science Foundation’s Center for Microbial
Oceanography<http://www.nsf.gov/news/news_summ.jsp?cntn_id=130087&org=NSF&from=news>have
discovered that marine cyanobacteria create tiny “vesicles” of carbon
and nutrients that act as a food source for ocean life. This is in addition
to themselves being the tiny plant life that forms the very foundations of
the oceanic food chain. They are very busy little bees, only they are
plants, and not bees.

Vesicles themselves are not news, having been observed in human-related
bacteria since the 1960s. However, this study marks the first instance of
their observation in ocean life, adding a new wrinkle to scientists’
understanding of these tiny workhorses.

“The finding that vesicles are so abundant in the oceans really expands the
context in which we need to understand these structures,” says MIT postdoc
Steven Biller. “Vesicles are a previously unrecognized and unexplored
component of the dissolved organic carbon in marine ecosystems, and they
could prove to be an important vehicle for genetic and biogeochemical
exchange in the oceans.”

The vesicles are indeed tiny, each approximately 100 nanometers in
diameter. For reference, that’s smaller than a HIV sample, and about the
largest diameter of something that could fit through a surgical mask. They
are truly microscopic.

Biller’s analysis of the genetic material in the vesicles recovered
directly from the environmental samples of sea water revealed sequences
from a diverse array of bacteria, suggesting that vesicle production is
common to many marine microbes. The researchers estimate the global
production of vesicles by *Prochlorococcus *alone at billions of billions
per day, which represents a notable addition of carbon to the otherwise
scarce nutrient pool of the open seas.

Besides serving as a food source, vesicles might also deflect viruses,
researchers said. Previous research has shown that viruses are more likely
to attack bacteria that have vesicles in them. Similarly, *P**rochlorococcus
*has lost the ability to neutralize certain chemicals and depends on
nonphotosynthetic bacteria to break down chemicals that would otherwise act
as toxins. It’s possible the vesicle “snack packets” help make this
relationship mutually beneficial.

As if that weren’t enough, researchers also found that the vesicles also
contain genetic information, meaning they might play a role in DNA and RNA
transfers, which help ensure genetic strength and diversity among
*Prochlorococcus
*population.

Vesicles – the multitaskers of the marine world.