micro fundamentals

• Most bacteria fall in this range
• All human pathogens

need plentiful oxygen

• need an oxygen-free environment.
• Poisoned by oxygen

Require low oxygen concentration

Require love oxygen and increased carbon dioxide

synthesize own food from simple inorganic carbon sources (ie: carbon dioxide)

must obtain pre-formed organic molecules from environment

feed exclusively on dead organic matter

feed on living organic matter

parasite that causes disease in host organism

water, beef extract, and peptone

• solid medium
• consists of nutrient broth and agar

used for preliminary isolation that favors the growth of a particular microorganism

Ingredients inhibit certain bacteria and encourage others

• ingredients allow colonies of different microorganisms to be more easily distinguished from each other
• (strep throat now quickly identified)

• lag phase – initialexposure
• exponential growth phases– aka log phase (symptoms start to appear)
• stationary phase –bacteria are starting to run out of nutrients/resources so there are equal numbers of bacteria replication and death
• death – aka logarithmicdecline phase (this is where we start seeing endospore formation)

streak bacteria across solid medium

• bacterial sample diluted in several tubes of agar medium
• agar poured into Petri dishes
• bacteria form discrete colonies where diluted the most
• used to estimate the number of original organisms present

two populations of organisms interact in a close and permanent association

interation benefits both organisms

one organism derives benefit while the other neither benefits or is harmed

two organisms living together resulting in them being able to accomplish what neither organism could do on its own

relationship beneficial to one organism but harmful to the other