In 2009 the former Homestake
Mine was a dark, wet, and difficult
place to conduct research. The
deepest mine in North America began
filling with water following its closure in
2002. As momentum built to turn the
mine into an underground lab, pumps
were installed to dewater the flooded
shafts and tunnels. As the water receded,
Rajesh Sani, PhD, was among the first
researchers to enter the deeper sections
of the mine.
“We went 5,000 feet deep, for sampling
which took a great deal of effort,”
says Sani, an associate professor in the
Department of Chemical and Biological
Engineering at SD Mines.
Sani and his team were not deep
underground hunting for precious
minerals, they were looking for bugs.
“The microbes we found were as good as
gold,” he says with a smile.
Extremophiles are microorganisms
that live in harsh environments. They
have learned to thrive in places like the
geothermal vents of the mid-Atlantic
rift, the frigid waters of Antarctic
lakes, or the veins of hot water found
in tiny cracks deep underground.
Extremophiles have evolved unique
characteristics that make them very
useful to scientists like Sani. Twelve
years after that first trip, the former
Homestake Mine is now the Sanford
Underground Research Facility (SURF).
Today, the microbes discovered inside
SURF are at the center of exciting new
research at SD Mines.
The BuG ReMeDEE
In 2017, the National Science
Foundation (NSF) awarded a $6 million
grant to Sani and his team to study the
range of extremophiles that consume
methane. The project is named Building
Genome-to-Phenome Infrastructure for
Regulating Methane in Deep and Extreme
Environments (BuG ReMeDEE). This
research (pronounced “bug remedy”) is
helping scientists better understand the
methane cycle in the hot water fissures
under Yellowstone National Park and
deep inside SURF. The methane cycle
is the generation and consumption of
methane by various microbes.
Researchers like Saurabh Dhiman,
PhD, in the chemical and biological
engineering department are also
exploring how some of these microbes
can be genetically engineered to better
convert methane into value-added
products or reduce the impact of future
methane emissions on the environment.
Venkata Gadhamshetty, PhD, civil and
environmental engineering department,
and Navanietha Rathinam,
PhD, chemical and
biological engineering
department, will be
converting methane
into biopolymers and
electricity using SURF
extremophiles. The
research could also open
doors for new economic
development opportunities
in industry that can utilize
these genetically modified
microbes for processing
greenhouse gas and
converting it to biofuel,
biodegradable plastics or electricity.
“This BuG ReMeDEE consortium will
garner the world’s attention on the
significance of analyzing the methane
regulation in deep subsurface and
extreme environments,” says Sani
the principal investigator of BuG
ReMeDEE.
Converting Plants to Plastic
The extremophiles discovered in the
Sanford Lab may also be key in building
an industrial process that can convert
plant matter into low-cost plastics that
are renewable and biodegradable.
A team of researchers with the
Composite and Nanocomposite
Advanced Manufacturing – Biomaterials
Center (CNAM), led by David
Salem, PhD, at SD Mines believe the
Sanford Lab extremophiles hold huge
commercial promise.
“The top ten petroleum based
polymers make up about a $500 billion
global market,” says Salem. “These
biopolymers potentially can cover the
whole range of properties of those.”
South Dakota’s Research and
Commercialization Council (RCC)
through the Governor’s Research Center
Program has awarded SD Mines CNAM
$1.8 million to develop commercially-viable
processes for manufacturing these materials.
Tip of the Microbiome
Sani and his team have made multiple
trips into the depths of the Sanford
Lab in the last decade. Each milligram
of mud or water brought back out can
yield thousands of microbes. Each trip
brings new discoveries and new species
and what’s perhaps most exciting are the
discoveries yet to come. “We know only
about one percent of the microbiome
in these areas, 99 percent remains
unknown,” says Sani.