plenty Issue 20 Feb/Mar 2008 | Page 36

science - tech

current

by

Terri Peterson Smith
Jameson Simpson

illustration by

Bringing Home the
Transgenic Bacon
Fish, meat, and dairy products
from genetically modified animals
might not be in supermarket
aisles yet, but transgenic
livestock do reside in barnyards
and fish tanks at some labs.
Here’s a look at what’s out there:

Udderly healthy cattle

Fast-growing
salmon
By introducing a growth
hormone gene assembled
from pieces of other fish
genes, biotech company
Aqua Bounty has developed
salmon that reach market
size twice as fast as
regular salmon.

Antibacterial
goat’s milk
Children in developing
countries may one day drink
milk from goats that have a
human gene for lysozyme—
an antimicrobial protein that
might prevent infections that
cause diarrhea and dehydration. Researchers at the
University of California,
Davis are raising the fifth
generation of these goats.

Pigs that produce
cleaner manure
A bacterial gene for the
enzyme phytase helps pigs
at the University of Guelph
digest more phosphorous,
cutting the amount of this
water-polluting nutrient in
their manure by as much as
60 percent.

>

Magic Muck

After a glance at the jars of muddy water in
Daniel Bond’s lab fridge, you might suggest the
University of Minnesota microbiologist throw
them out. But the muck is worth a closer look. It
may hold the key to developing clean energy.
The jars contain Geobacter sulfurreducens,
an electricity-producing microbe that feeds
on organic material (even sewage) in sediment at the bottom of oceans and lakes for
energy. When breaking down molecules,
electrons flow from the bacterium to metals,
such as iron, in the soil, creating an electrical current. Geobacter already helps clean up
sites polluted by toxic heavy metals: When reduced by the microbe, the metals precipitate
into solids, which are easier to remove.
Bond studies how the microbes generate
current and how to make them do it better.
Others are designing devices, called microbial

findings

1

Climate change could
shift the ranges of 130
North American tree species northward by hundreds
of kilometers and shrink the
ranges of some by as much
as 58 percent.

2

Israeli researchers
figured out how venom
from jewel wasps turns
cockroaches into zombies.
After stinging, wasps lead
the victim by the antennae
to their burrow. There the
roach is consumed by wasp
larva from the inside out.

Visit PLENTYMAG.COM for more on the
growing controversy over GM animals.

34 | february-march 2008

fuel cells (MFCs), to harness bacteria’s power.
Though some prototypes exist, the technology
faces major hurdles. “So far we can do tricks,
like make a light bulb burn, or run a toy robot,” says Bond, “but we can’t economically
put it to use on a larger scale yet. We need a
way to get more power.”
Researchers have made small-scale
progress. The Naval Research Laboratory’s
microbe-powered weather buoy in the Potomac River monitors air and water conditions.
And in 2007, Foster’s Brewing Company installed an MFC at its brewery near Brisbane,
Australia. The “beer battery” produces energy from brewery wastewater, treating it
in the process. It generates only about two
kilowatts of power, but beer lovers should
still lift a pint to toast sustainable brewing and the magic of microbes.

3

A new system called
V2G allows batteries
of electric and hybrid
cars to store or supply
grid electricity. Such a
system could help smooth
peaks in energy demand:
100 of the vehicles
could provide 1 megawatt
of storage.

4

For the first time,
biodiesel alone fueled
an airplane. BioJet 1—
a Czechoslovakian-made
L-29 jet that runs on
vegetable oil refined
into biodiesel—climbed
to 17,000 feet and flew
for more than 37
minutes in Nevada.

5

As if rising global
temperatures and
shrinking sea ice weren’t
enough of a threat to
polar bears—the practice
of selectively hunting males
could eventually leave females without mates.

6

Researchers proposed
a novel way to mitigate
global warming: Enhance the
ocean’s ability to absorb CO2
by building water treatment plants that remove
hydrochloric acid from
seawater and neutralize it.
One hundred such plants
could reduce 15 percent of
global CO2 emissions; 700
could offset all of them.

photo by © Ram Gal (bottom center)

USDA scientists have introduced a bacterial gene into
Jersey cows that produces
lysostaphin. This protein
k ills the bacteria S. aureus,
which causes mastitis, an
udder infection that is
difficult and costly to treat.