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Useful Microbes
Microbes can be beneficial to us?!?
Useful Microbes
There are billions of microbes and lots more we haven’t discovered yet
Most of these microbes are either • Necessary for our survival• Good for us• Can be used for our benefit in industry
In NatureMicrobe – plant Interaction
– Many microbes are found in nature and help plants to grow
– Rhizobacteria found in the soil fixate nitrogen which is required for many crops to grow
Roots
Microbes
In Nature
• Oxygen production– Cyanobacteria or
‘blue-green algae’ produce oxygen in the ocean
In Nature• Decomposition
– Defined as the breakdown of raw organic materials to a finished compost
– The fungi invade the organic matter in soils first and are then followed by bacteria.
– Without this recycling of inorganic nutrients, primary productivity on the globe would stop.
In the Food Industry• Cheese and yogurt
– Lactic acid fermentation produces yogurt and cheese. Some fungi are also used to make the cheese turn blue!
• Bread and dough products– Yeast is used to make bread and
dough products.
• Alcohol Production– Yeast is also used in alcohol
production when fermentation occurs without air
Lactobacilli bacteria used in yogurt and cheese making
Saccharomyces cerevisiae yeast used in bread making and
alcohol production
In the Food Industry
• Fermentation– A process during which the bacteria break
down the complex sugars into simple compounds like carbon dioxide and alcohol.
– Fermentation changes the product from one food to another.
In Medicine• Penicillin
– Discovered by Alexander Flemming in 1928
– Produced by the fungus Penicillium notatum
– One of the most commonly used antibiotics today
• Vaccines– Discovered by Edward Jenner in 1796
– Usually made from weak or inactive versions of the same microbes that make us ill
The fungus Penicillium produces the antibiotic Penicillin
Probiotics• What are they?
– Live microorganisms which when administered in adequate amount confer a health benefit on the host
• What type of bacteria are they?– Lactobacilli which are part of the
beneficial natural microflora found in the human gut
ProbioticsHow do they work?
– Interacting directly with the disease-causing microbes, making it harder for them to cause disease
– Reinforce the natural barrier of the digestive tract protecting against pathogenic microbes
– "Competitive exclusion" in which beneficial microbes directly compete with disease-causing microbes for food and other resources, eventually crowding them out
– Interacting with and strengthening the immune system
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