Scientists
studying microbiomes have created a framework for predicting how the
composition of these complex microbial communities may respond to changing
conditions.
The
review study, led by Jennifer Martiny, professor of ecology & evolutionary
biology at the University of California, Irvine, appears in the Nov. 5 issue of
Science. It presents a far-reaching assessment of microbiomes that could affect
efforts to improve human health and the health of all Earth's ecosystems.
Microbiomes
are collections of microscopic organisms -- such as bacteria, viruses, archaea,
fungi, protozoa, algae and plankton -- that inhabit ecosystems as varied as the
human digestive tract, the ocean and soil. For instance, the 100 trillion
microbes in the human gut -- which vastly outnumber the "human" cells
in our bodies -- are critical to our health and development.
A
few grams of soil or sediment may contain tens or even hundreds of thousands of
microbial species, each interacting with the others. Together, they are largely
responsible for the processing of nutrients and carbon in soil -- regulating
the decomposition of waste materials, the regeneration of
soil fertility and greenhouse gas emissions.
The
study delves into microbial evolutionary processes and explores previous research
showing that microbial traits -- particularly with bacteria -- vary predictably
in how they have evolved across the "tree of life." For example, some
traits, such as photosynthesis, evolved a long time ago and are shared by large
groups of genetically related bacteria. Other traits, such as sensitivity to a
particular virus, have evolved many times in many small groups.
Patterns
of microbiome diversity among samples can reveal more information than
previously thought when paired with the evolutionary history of microbial
traits. Microbiologists could use this information to narrow down the reasons
for differences in microbiome diversity among many samples.
The
planet hosts a vast variety of microbial communities, from those in undersea
volcanos and plant ecosystems to untold numbers of microbes in the human body
that fight disease. These microbiomes share many similar traits, and further
research on them could reveal basic information about Earth and its
inhabitants.
See:
Posted by Dr. Tim Sandle