production of polyurethane derivatives (specialized ‘plastics’).
Fresh out of college with your degree in Microbiology, you have landed your ‘first real job’ as a
scientist with “DuPunt”, a company that specializes in the development and production of
polyurethane derivatives (specialized ‘plastics’). Dupunt worked with NASA to design the
sample return vehicle (SRV) that was responsible for the return of Martian soil samples,
described in the journal article by Kenneth Nealson (Ann N Y Acad Sci. 2001 950:241-58).
The DuPunt CEO was very interested to have her company support the NASA mission to find
life in the universe. She also realized that participation in the mission offered DuPunt Company
an uique, high profile business opportunity. He convinced NASA to showcase a new
polyurethane protective coating on the robot carried in the SRV. His idea was to dress the robot
like the singer Elvis Presley and bring wide attention to the Mars mission. As part of this public
relations campaign, he has named the robot “ELVIS” (Extraterrestrial landing vehicle integrated
You are not quite sure why DuPunt has a Microbiologist on staff, but you are about to find out
why the company desperately needs one now.
Your boss has called you into his office. “Read this article!” he says, pushing the front page of
The Washington Post across his desk to you. Here is the article:
ELVIS NAKED, SKINLESS UPON
RETURN FROM OUTERSPACEThe recent return to Earth of Martian soil
sampler ELVIS has provided scientists with
the opportunity to determine if Martian soil
contains viable microorganisms. Although
NASA scientists have made great advances
in understanding the physical and chemical
conditions on the surface of Mars, perhaps
the most interesting discoveries are yet to
come as biological scientists begin to
analyze the soil samples. Designed to gather
samples and maintain them in their normal
atmospheric and temperature conditions,
EVLIS is a sophisticated robot and is the
most expensive component of the SRV
probe. Inspired by the acronym for the unit
(ELVIS), workers constructed this robot to
resemble music legend Elvis Presley, and
even fashioned a white Spandex jumpsuit,
made out of DuPunt polyurethane to enclose
DuPunt Chemical company has benefited
tremendously from all of the publicity, and
has seen its sales of polyurethane quadruple.
This ‘human connection’ has been
instrumental in convincing Congress to
provide the necessary funding for NASA
and its many related space exploration
However, the successful completion of the
SRV mission has generated a mystery, one
that has led to accusations of contractors
providing substandard materials (in
particular defective plastics) used in the
SRV or of someone intentionally sabotaging
the plastic components of the SRV in an
This opening was part of a special,
televised ‘welcome home’ ceremony in
which ELVIS was supposed to ‘dance’
down the SRV exit ramp and speak his
trademark words, “Thank you…thank you
very much for supporting this critical
space exploration mission.”
NASA scientists and on-lookers at the
ceremony were shocked to find that
ELVIS’s jumpsuit had been reduced to a
slimy puddle. Even more distressing was
the deterioration of ELVIS’s ‘skin’ (a
version of Lycra specially developed to
resemble human skin). This too was
reduced to a slimy residue that dripped
from the metal ‘skeleton’ of the ELVIS
unit. The deterioration of the plastic
components of ELVIS ruined what
organizers had planned to be a touching
ceremony at the mission’s completion.
ELVIS’s exit from the otherwise intact
spacecraft was met by gasps and screams
from the gathered audience. “It was a
terrible sight!” said one member of the
audience. “We expected to see the King,
but we saw a horrible mess, a grotesque
parody of Elvis. Without his plastics lips,
I couldn’t understand a word he said…and
the smell was horrible! I’m telling you, I
thought I was going to hurl!!” said one
NASA official who wished to remain
Television viewers were spared much of
the trauma of these sights as networks
quickly switched to a new episode of Dino
Squad in which a cartoon version of the
ELVIS helps five teens transform intoattempt to embarrass the U.S. space
Upon its return to Earth, the SRV capsule
was opened to allow scientists to recover the
dinosaurs and use their powers to protect
the Earth from global warming. An
investigation is underway.
Stifling your initial reaction (“Oh yeah, new Dino Squad!”) you manage to mumble “What a
“Yes. Yes. And this could take an ugly turn for DuPunt!” answers your boss. “I’m not sure
what caused this mess, but I do know a couple of things that didn’t make it into that Post article:
● the only plastics showing damage in the SRV were polyurethanes;
● our company (DuPunt) provided those polyurethane products to NASA at a cost of
$15,000,000. We’re in big trouble if we can’t prove that something from MARS is
responsible for destroying ELVIS
He continues, “The polyurethane products we provided were first-rate. We didn’t cut any
corners with this stuff. Products from the same batches of polyurethane have been into outer
space before, and they returned just fine. There must be some explanation other than our
incompetence. This is where you come in: I need you to find that explanation!”
“Why me?” you ask.
“Because of the stink!” your boss answers. “Some of the scientists present at the ELVIS disaster
said the smell reminded them of an old fermenter or an autoclave. Those are microbiology terms,
aren’t they?” says your boss. “Those comments tell me that this whole stinking mess might be
caused by microorganisms…you know: bacteria, fungi, viruses, germs…something like that.
Get right to work on this! You and I will have to work closely on this, you know. I’ll handle all
the communications with the press, and you handle the science….just make sure that you explain
everything to me so that I can speak about it to the press without making a fool of myself and
Okay. You are a trained scientist…you can do this! What do scientists do? They answer
questions by testing specific hypotheses.
You are so happy that you took a lot of Microbiology classes, because they taught you what
scientists do! If you are going to determine what happened to ELVIS, you must develop atestable hypothesis, and then generate data
to determine if your explanation makes sense. As a
Microbiologist at DuPunt you must determine what has happened to the polyurethane.
As an employee of DUPUNT Here is your hypothesis:
“The degradation of polyurethane products was caused by a microorganism or
microorganisms present in the soil samples collected by ELVIS.”
As a first step in testing your hypothesis, you believe that it should be possible to visualize
microorganisms in the degraded goo by microscopy.
To test this hypothesis, you will need to think about some specific experiment(s), but you will
also need to learn and/or remember some basic Microbiology.
As you address this large question, ask yourself:
● What do you know at this point that will help you to address this hypothesis?
● What do you think you need to know/learn to be able to test your overall hypothesis?
How realistic is the DuPunt Microbiologist hypothesis?
Is your boss just grasping at straws, or is there really a possibility that Microbes from
Mars could be the culprits in the degradation of the polyurethane?
In order to answer this question, you need to find out several things. One thing
you would need to explore is whether there is any evidence that microbes could
omewhere other than earth.
To help you consider the support for your hypothesis, we will provide some specific smaller
questions: PAK questions.
For the ELVIS Meltdown case there will be 4 PAK questions.
Using light microscopy, you examine the soil samples and the ’goo’ from the degraded
polyurethane. Will this approach allow you to observe all microorganisms present in the
Why or why not?
What are the limitations of this approach?Question two
You use phase contrast microscopy to observe a wet mount of a soil sample (the first
picture below) and a “goo” sample (the second image below) from the ELVIS. In what
ways are the potential ET microbes similar to microbes previously characterized on
Earth? In what ways are they different? How could
you determine whether the microbes present in the soil or goo samples are
phylogenetically similar or distant from known microorganisms on Earth?
Your boss has done a little reading about microorganisms, but he finds it all pretty
confusing. ”Dude it’s like a foreign language!” he complains. ”I have to face the press to
explain our idea that microbes might be responsible for all the damage to ELVIS, but I
can’t even pronounce most of these terms, much less explain them. I think that it will
help my press conference presentation a lot if I can use some visual aids. What I want
to do is explain to my audience what bacteria look like. You know the functionalarchitecture of bacteria and how they might be
able to degrade polyurethane. I think that
eukaryotes might be too complicated for this audience, so I just want to show them what
Gram-negative bacteria look like in a schematic diagram. I’ve put together this diagram
of a typical Gram-negative cell. Take a look at it and make any corrections you think are
necessary. Notice that I not only labeled the features, I also indicated the major
biochemical composition and function(s) and of each main feature. Oh yeah this figure
will probably make it into lots of newspapers, magazines, and web sites, so it needs to
be scientifically correct. We wouldn’t want to make DuPunt look stupid, would we?
Anywho I’ve already done most of the work. Just proofread it and make a list of
What corrections would you make to [A], through [G], if any?