Microbiology in the Environment

• What is an environment?
o The air, water, minerals, organisms, and all other external factors surrounding and affecting a
given organism at any time.
o Ecology: the study of how organisms interact with one another as well as the environment
o Energy flow: main currency in ecology
- flow of elements: carbon, O2

Sun——> matter
———> is given off by producer & consumer——->decomposer——>inorganic nutrient pool
Producer——->decomposer

Sun ——-> energy——-> producer——->consumer——->heat
producer——>heat consumer——>decomposer——->heat
Producer——>decomposer

Compost piles give off a lot of heat
Inorganic nutrient pool: matter
- Inorganic carbon, nitrogen, sulfur (not attached to carbon that has hydrogens attached
- Methane (natural gas)
Trees: two inorganic pools: air and soil
Microbes as Producers: produce oxygen in the world (deep sea)
Microbes mediate the transfer of matter
Ex: cows——> digest grass (microbes)
Microbes as Consumers
Microbes transfer matter as decomposer
Microbes as decomposer
Microbes mediate matter to inorganic nutrient pool

o Cycles
Nutrient cycles:
- carbon cycle, oxygen cycle, phosphorus cycle
- 25.3 figure
- Microbes liberate carbon up, fix carbon down into organisms, both oceans and fresh
water

▪ Water
▪ Carbon
▪ Nitrogen
- Figure 25.4
- Denitrifying bacteria
- Plant and animal decomposer
- Ammonia into nitrate