4th Flashcards
The role of microorganisms
- Agents of disease
- Agriculture
- Food
- Industry
Cause disease in humans, plants, and animals
agents of disease
a disease-causing microorganism
pathogen
➢ Microorganisms are involved in cycling of plant nutrients
➢ Bacteria regulate nutrient cycles, such as the nitrogen cycle and the sulfur cycle, transforming
and recycling nutrients that form the basis of soil fertility
agriculture
bacteria convert atmospheric nitrogen (N2) into ammonia (NH3). NH3 is the major nutrient found in fertilizer and is used as a nitrogen source for plant growth
nitrogen fixation
- occurs in the nodules found in the roots of legumes (beans, peas, and lentils)
nitrogen fixation
Microorganisms inhabit the rumen of ruminant animals, such as cattle and sheep.
Microorganisms in the rumen convert cellulose from grass into fatty acids that can be used by
the animal
agriculture
a microbial ecosystem in which microbial communities digest and ferment the
polysaccharide cellulose, the major component of plant cell walls. Without these symbiotic
microorganisms, ruminants could not thrive on cellulose-rich food such as grass and hay
rumen
➢Microbial growth in food can cause food spoilage and foodborne disease
➢Beneficial microbes have been used for thousands of years to improve
food safety and to preserve foods
food
Microorganisms can be harnessed to produce commercially valuable
products.
industry
Naturally occurring microorganisms are grown on a massive scale to make large amounts of products:
- antibiotics
- enzymes
- certain chemicals
Biotechnology employs genetically engineered microorganisms to synthesize products of high value:
- insulin
- human proteins
product of the anaerobic metabolism of
a group of Archaea called methanogens
Natural gas (methane, CH4)
is a major fuel supplement, which is produced
by the microbial fermentation of glucose obtained from carbon-rich feedstocks such as sugarcane, corn, or rapidly growing grasses
Ethyl alcohol (ethanol)
