The strange, beautiful and
powerful world of microbes
RAVINDER NAGPAL1, A.K. PUNIYA1, M. PUNIYA2, ARTI BHARDWAJ3,
KISHAN SINGH1 AND HARIOM YADAV4
1Dairy Microbiology, 2Dairy Cattle Nutrition, 4Animal Biochemistry,
National Dairy Research Institute, Karnal 132001, (Haryana); 3CAEHS,
Meerut (UP), India.
The first MICROBIOLOGIST
and his MICROSCOPE
Anton van Leeuwenhoek - A classical example of serendipity. By
wanting better magnifying lens with which to judge the quality of
the cloth he was buying Leeuwenhoek discovered bacteria
What Microbiologists Do ???
• Work in almost every industry - from food, agriculture and
pollution control to biotechnology, pharmaceuticals and health,
government agencies and labs, in education as teachers and
researchers.
• No one microbiologist can study everything! That's why people
who become microbiologists usually focus on a particular microbe
or research area.
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Bacteriologists focus on bacteria.
Virologists specialize in viruses.
Mycologists study fungi.
Epidemiologists track down outbreaks of disease
Immunologists study how the body defends itself against
microbial invaders?
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What is a microorganism?
• An organism that is too small to be
seen clearly with the naked eye.
• Generally single cells, but some
exist as cell clusters; often work as
a community
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Where do microbes fit in the
biological world?
Microbila cell: Efficiency in deficiency
‘Most of the vital organs of eukaryotes are missing’
The power of microbe lies in its speedy
growth
Imagine the weight of biomass of E.coli after 24 hrs under optimal growth?
Never underestimate the
power of a Microorganism.
• Microorganisms, just like God cannot be seen through
naked eye but we can feel their impact on us in various
ways.
• Though only 3% of the total microbial population are
harmful to the humans.
• Without knowing, we are getting their help from the
historic days eg. souring of milk (dahi), pickels, jams,
dosa and idly making, wine production etc.
“Microbes are always at Work”
Mind it…
contd…
•The pressure inside a bacterial cell is about 2 atmospheres,
which is roughly the same as the pressure in a car's tyre.
•A human can be killed by exposure to less than 500 rad
radiation. However, Deinococcus radiodurans is a bacterium,
which can survive exposure to upto 3000000 rad of ionizing
radiation.
•'Botulin‘, a toxin produced by Clostridium botulinum, is
highly toxic and if everyone has to be killed on this earth, less
than 1kg of this toxin will do.
Bacterium: as big as the head of a
fruitfly and can even "hold its breath"?
• A giant bacterium, Thiomargarita "sulfur pearl of Namibia,“.
• The bacteria (3/4 mm wide) about 100 times larger than the largest
known, Epulopiscum fishelsoni.
• Thiomargarita namibiensis lives on the nitrogen and sulfide on the
ocean floor produced by rotting plankton and algae.
• Nitrate however is not steadily available, so they "hold their breath"
while they wait for something to stir up off the ocean floor.
• They do this by storing sulfur just under their cell wall, and keeping
nitrate in a big sac. This could be one of the reasons why the
bacterium is so big.
A Humongous Fungus
• Did you ever wonder what the world's largest organism is?
• Maybe you'd pick an elephant or a giant whale.
• Well, those choices would be wrong; this organism is actually
a soil Fungus, Armillaria bulbosa, found in a northern
Michigan hardwood forest.
• It is most likely one of the world's oldest organisms as well,
exceeding 1,500 years and weighing over 100 tons.
• It is actually a plant pathogen, whose hyphae pierce the roots
of aspen trees and absorb nutrients from them. Therefore,
the majority of the fungus is underground and only tiny
edible ‘honey mushrooms’.
Facts About Microbes
• Microbes outnumber all other species and make up most
living matter (~60% of the earths biomass).
• Less than 0.5% of the estimated 2 to 3 billion microbial
species have been identified.
• Microbial cycling of critical chemical elements such as
carbon and nitrogen helps keep the world inhabitable for
all life forms.
Contd…
• Microbes generate at least half the oxygen we breathe.
• Microbes are roots of life's family tree. An understanding
of their genomes will help us understand how more
complex genomes developed.
• Microbial genomes are modest in size and relatively easy to
study (usually no more than 10 million DNA bases,
compared with some 3 billion in the human and mouse
genomes).
• Microbial communities are excellent models for
understanding biological interactions and evolution.
Strange Facts and Bacterial Records!!!
(Omnipresent).
Everything is everywhere, the environment selects - Beijerinck M.W.
Microbes thrive in an amazing diversity of habitats in extremes of
heat, cold, radiation, pressure, salinity, acidity, and darkness,
and often where no other life forms could exist.
Contd…
• Underground: Chemolithotrophs found in Basalt deposits 1500m
(4700 ft) underground in solid rock.
• The Sky: Some bacteria spend their whole lives in the
atmosphere, growing and reproducing in the clouds above our
heads.
• On Ice: Some bacterial species live in the ice of glaciers and others
have often found in the snows of the North and South poles at -17
and -85°C.
Contd…
• Not So Cool: Some bacteria have learned to live in hot springs.
Some species are happy at 75°C while others think even this is
cool. Species of Aquifex can live in water as hot as 95°C. Archaea
are happy to grow deep sea hydrothermal vents at 106°C
• The Deep Sea: Bacteria ‘known as Extreme Barophiles’ live at
depths of >10000 m and are able to survive pressures in excess of
1000 times the air pressure at sea level; and they cannot function
properly at pressures less than 400 atmospheres and may die in a
couple of hours if brought to the surface.
Life in the extremes
Sahara desert
Life in the extremes
Yellowstone National park
Life in the extremes
Lake Magadi, Tansania
Life in the extremes
Yellowstone National Park
Life in the extremes
Life in the extremes
Contd…
• Fast Movers: Some bacteria can move by flagella that enable them to
obtain speeds as high as 0.00017 km/ hr. This may not seem very fast,
but remember that we are talking about very small organisms. They
are travelling at about 50-60 body lengths/ sec which is equivalent to
a 6 ft tall man running at 100 m/ sec, 9 times faster than the world
record. Cheetahs, are the fastest animals on land but even they only
move at about 25 body lengths/ sec.
“What is soil, becomes grass, becomes a cow, becomes you
and me and then becomes soil again. Without microbes,
the whole ecosystem would collapse”
Facts About Beneficial Bacteria
• The opposite of antibiotics are probiotics - a term coined
in 1965 to describe substances that favor the growth of
beneficial microorganisms in the body.
• Two species of probiotics, Bifidobacterium and
Lactobacillus, have been studied the most.
• Bacteria that produce the enzyme lactase help reduce
lactose intolerance.
Tell me what you eat,
and I will tell you what you are - Brillat-Savarin
Learn a lot from a microbe
• Halobacterium, may hold the key to protect astronauts from one
of the greatest threats they would face during a mission to
Mars: space radiation.
• The harsh radiation of interplanetary space can penetrate
astronauts' bodies, damaging the DNA in their cells, which can
cause cancer and other illnesses.
• Halobacterium appears to be a master of the complex art of
DNA repair. This mastery is what scientists want to learn from.
Serratia has a religious history and
can cause severe infections in humans?
• Serratia marcescens, when grown in colonies, produces
a bright red pigment similar to the appearance of
blood.
• In mediaeval churches priests would discover that
bread left in moist places would "miraculously"
produce this "blood", thus leading to the belief that the
bread's red appearance was because it had been
stabbed by unbelieving Jews.
• In 1819 Bartolemeo Bizio, a pharmacist, discovered that
the red pigment occurred because of bacteria.
Martian microbes may exist ?
• Life On Mars??? No one knows for sure yet!
• But in August 1996, scientists announced that they had
extracted what they believed to be fossils of an unknown
bacillus shaped microorganism from inside a meteorite from
Mars found in Antarctica..
• The meteorite left Mars 16 million years ago and landed in
Antarctica 13 thousand years ago.
• This may support the theory that life did or does still exist on
Mars!
Wow! Life on the Red Planet!
We are not alone! Or are we?
Shergotty, Bihar, India (1865)
Mars - Climate and Life
Postulated Mars-Biosphere
Mars-Climate and Life
Liquid water only in deep subsurface regions
Life either extinct or in subsurface niches:
Mars from Pathfinder
Life on Europa? Moon of Jupiter
Antarctica, 1984
Bacteria sometimes catch A Virus
Bacteriophages – “bacteria-eaters”,
viruses that use bacteria to multiply
In the 1990s, bacteriophage research became an alternative
for scientists worried about antibiotic resistance.
Researchers in America followed the example of scientists in
Western Europe who were treating patients with
bacteriophages and obtaining great results.
When antibiotics don't work for a bacterial infection, doctors
can use bacteriophages to kill the bacteria. Although ironic, a
virus can make us feel better!
Microbes enables cows to eat grass?
o Microbes living in the rumen of the cow are
responsible for the breakdown of the carbohydrate
cellulose of plants.
o The cow lacks the enzymes to break down
carbohydrates.
o Without microbes and their enzymes, ruminants
would not be able to derive
any energy or nutrients
from a diet of grass.
Microbes have a built-in compass?
• Aquatic, anaerobic bacteria called magnetotactic
bacteria find their way around by using the attraction
from the earth's magnetic field.
• When placed near a magnet, they are attracted to the
magnet's northern pole because the bacteria make
magnetic particles which contain iron.
• When lined-up, the particles make a long magnet that is
used by the bacteria as a compass.
• It is this built-in compass that enables the bacteria to
find its way down to the deep, oxygen-free parts of its
aquatic habitat.
Diamonds are made from dead bacteria???
• Carbon, the main component of most diamonds, usually
contains an isotope of light carbon (12C), which is utilized by
some living organisms.
• Therefore, eclogitic diamonds with large amounts of the
isotope 12C, are believed to have an organic origin.
• These were formed from carbon near hydrothermal vents
which was also utilized by the bacterial communities near
the vents.
• Thus through time, heat and pressure were able to turn the
carbon along with the bacterial colonies into diamonds.
"So, those sparklers of yours may just be clumps
of billion-year-old bacterial corpses"
Microbial Jugnu:
Bacteria that emit visible light?
• Lightning bugs make light, but interestingly enough, bacteria
produce light in basically the same process called
bioluminescence.
• ‘Luciferase’ - uses molecular oxygen and a protein that has a
particular vitamin FMNH2 attached to it.
• ‘Luciferase’ - causes oxidation reaction to occur between
oxygen and vitamin leading to the conversion from FMNH2 to
FMN.
• As this occurs, luciferin emits visible light!
• The color of light (orange, yellow, yellow-green, or blue-green )
depends on the kind of luciferase and amount of oxidation of
the vitamin attached to the luciferin.
Enzymes that bacteria use to break down dead,
chilled whales may be used in cold-water detergents?
• The cold temperature slows the rate of biological decay and
in a whale, the oil-laden bones are the last things to be
decomposed by bacteria at depth of 3300 feet.
• The detergent industry's current fat-digesting enzymes are
only effective in warm water, 105ºF.
• Therefore, in cold water the enzymes do not gulp up oil or
grease. Hence, a tremendous amount of energy savings
could be obtained when using a cold-water enzyme that
worked on stains.
Microbes can degrade explosives?
• Trinitrotoluene, TNT, is a problematic explosive that
contaminates the soil in areas where ammunition is
kept.
• Bacteria named Clostridium bifermentans is able to
break down this contaminant.
• When provided with starch as energy source, the
bacteria can break down the TNT through cometabolism by broken-down TNT as a source of carbon.
Bacteria can help clean up oil spills?
• After the Exxon Valdez crashed off the shore of Alaska,
spilling its contents all over the area, one of the biggest
contributors to cleaning up the environment was
Pseudomonas.
• Scientists found that by feeding the contaminated area with
oxygen and waste water, the bacteria present there were
provided with the nutrients needed to flourish, thereby
encouraging the break down of hydrocarbons within crude
oil by Pseudomonas.
• The hydrocarbon that the bacterium feasts on are converted
to carbon dioxide and water.
Microbes might be used to breakdown dirty
laundry on long space flights?
• One of the problems that would be encountered,
which is now one of the problems with the
Russian space station Mir, is the disposal of dirty
laundry.
• Presently, there are only two supply trips a year
to Mir, so six months of stockpiling doesn't work
too well.
• Russian scientists are working on developing a
mixture of bacteria that could be used to
biodegrade dirty underwear.
Bacteria keep vegetables fresher?
• Even vegetables that are kept in airtight containers are
prone to spoilage by E.coli and Listeria.
• Lactic acid bacteria, are an alternative solution to this
problem by producing natural acids that prevent
Listeria from growing in foods.
Bacteria are used to make
chocolate?
• Chocolate comes from the seeds of the Cacao
tree.
• The seeds come in pods and the only way to
retrieve the seeds are to ferment them with yeasts
and lactobacilli and Acetobacter.
• The Lactobacillus secretes an acid to help break
apart the pod.
Microbes can make plastics ?
• Alcaligenes eutrophus, is a useful bacterium having
the capability of making plastics.
• The bacterium is able to accomplish this feat because
it has granules that are made of a fat-like polymer
and not starch, like the granules of other bacteria.
• These plastics can be readily degraded and
hopefully will pose less environmental threat.
• There are strong hopes of using these bacteria and
their plastics for medical purposes.
Microbes are all over your skin?
• While bacteria are found on your fingers, toes, arms and legs
they are far more numerous on your face.
• They are found above and below the surface of your skin and
are in no way harmful.
• However, all teenagers have had at least one zit in their
lifetime, are called: pimples, blackheads, whiteheads,
blemishes, acne, etc.
• And while bacteria are not the cause for zits they do inhabit
those little imperfections. So, the next time you pop your
pimple you must know that you are unleashing an army of
microbes.
Microbes cause body odor?
• The sweat that comes out of your underarms actually
does not smell bad.
• The reason that people give off odors when they
sweat in their underarms is that bacteria living there
like to eat sweat, and as a result produce waste
products that cause it to smell.
• Body odor can be eliminated by using deoderant.
• Deoderant kills the bacteria under your arms so that
it cannot make your sweat stink.
“So don't forget your deoderant; it does more than
just mask body odor, it stops it before it happens!”
Sick Building Syndrome?
• Fumes from certain construction materials in buildings
e.g. malls, are responsible for giving people severe
headaches.
• Microbes living in potted plants eliminate Sick Building
Syndrome by degrading the fumes.
• However, suffering people may be glad to know that
helpful bacteria can solve their problem.
Mycobacterium tuberculosis is the literary
microbe?
• Famous writers like Keats, Browning, Austen
and Orwell have all suffered from tuberculosis
and because of this the microbe has been called
the literary microbe.
• Tuberculosis is also considered to be the greatest
killer of all times. About one hundred thousand
million people have been affected. This bacterium
is transmitted through air or infected milk.
Microbes form fossils?
• In 1950's-1960's, micropaleontologists discovered layers
of sedimentary rocks, wavelike stromatolites in Great
Lakes, are believed to contain microbial fossils.
• Some fossils are 3.5 billion years old, meaning that they
were formed only one billion years after the creation of
the Earth indicating that microbes are the earliest forms
of life on Earth.
There's a "Sleeping Beauty" story
for bacteria?
• In May 1995, scientists were the prince as they revived
25-40 million year-old bacteria from the stomach of a
bee that was preserved in tree sap.
• It was this event that led to the notion of Spielberg's
Jurassic Park, where dinosaurs were created after
their DNA was extracted from mosquitoes trapped in
tree sap the same way.
“The dinosaurs, however, were the ones who took the limelight
away from the bacteria on the movie screens”
How Does Salmonella Get
Inside Chicken Eggs?
• The bacterium actually lives in the feces of chicken.
• Because chickens sit on their eggs, even before they are collected
for consumer purchases, the eggs may be subjected to the
bacterium.
• It was found that S. enteritidis could actually penetrate the hard
outer shell of the egg and live inside the yolk, where it can
reproduce.
• The bacterium could infect hens' ovaries, and contaminate the
egg before it even developed a shell.
Infected rats make easy cat snacks
• Toxoplasma gondii, a parasitic infection in rats, alters their
natural behaviour and makes them easy prey for cats.
• Toxoplasma gondii is found in about 35% of rats but prefers to
live in cats.
• It ensures its return to its favourite host by affecting the brains of
the normally cautious rats, making them outgoing and active and
an easy meal for a hungry cat.
• Rats can usually detect subtle changes in their environment. It
makes them very hard to trap or poison but this parasite
overrides the innate response - they almost taunt the cats in a
sense (remember Tom n Jerry ???).
Caught Dirty-Handed!!!
• When was the last time you washed your hands?
• Did you use soap?
• What have you done since you washed?
• Have you eaten, put your fingers in your mouth or touched
someone else?
• There are millions of microbes on your hands. Most are
naturally occurring and harmless. But some may be diseasecausing germs. Hand washing with soap lifts off those
microbes and rinses them away.
• Observations in public restrooms reveals what?????
Bacteria can help give your jeans
the right ‘fade’
• Alkalothermophilic Thermomonospora
produces enzyme cellulase, which when
mixed with a coarse denim cloth reduces its
hairiness and makes it softer and lighter.
• It gives same appearance as a stone wash,
causes no damage to drums of washing
machines by preventing wear and tear of the
material.
• Finish can be controlled to desired level by
controlling the amount of enzyme.
Bacteria can act as insecticides?
• The first major products of agricultural
biotechnology was Bacillus thuringiensis,
producing proteins that are toxic to many
insects.
• Now, scientists have spliced genes of it into
crops, that produces toxins fatal to crop
damaging pests, but harmless to "good" bugs.
Thanks
for your kind attention