Chapter 4 Flashcards
1 nutrient needed for cellular growth
glucose
Colony
A large group of bacteria that are visible to the naked eye
Binary Fission
The reproduction Process of Bacteria
What is important to know about biofilms and their relationships w/ other bacteria?
Biofilms are colonies of bacteria that have a mucosal coating to them, allowing them to stick to surfaces. Theses biofilms can have more than one type of bacteria cohabitating
antiseptic v disinfectant
antiseptic is for living organisms and disinfectant is used on no living things to make them sterile
Contaminant
A contaminant is a bacteria that grows in the media, that was not purposefully introduced
How do bacteria compete w/ one another for the same space/nutrients?
Bacteria can inhibit the growth of other bacteria, or purposefully inject them w/ a toxin to kill then
Quad-streak method
used to make a pure sample, or to isolate a pure colony of bacteria on an agar plate
Closed System
A media in which no additional nutrients are added to aid the growth of bacteria
5 phases of the growth curve
Lag, Exponential, Stationary, Death, Prolonged decline
What phase is most important in antibiotic development
Exponential growth
What are the characteristics of colonial growth in bacteria?
The bacteria on the edges and top of the colony are the healthiest and have the most access to nutrients as there is no competition. The inverse is true for the bacteria on the bottom of the colony.
temperature specific bacteria
Psychrophiles
Psychrotrophs
Mesophiles-thrive in average temperatures (3
Thermophiles
Hyperthermophiles
Major Environmental factors affecting Bacterial Growth
Atmosphere, temperature, pH, H2O
Atmosphere specific Bacteria
Obligate Aerobes-need O2 to live
Facultative Aerobes- Can use O2 but will use fermentation in its absence
Obligate anaerobes-Cannot use O2 and will die where it is present
Microaerophiles-requires a small amt of O2 to thrive
Aerotolerant anaerobes- Use fermentation only but can survive in the presence of O2
ROS
Reactive O2 Species
Ph Specific Bacteria
Neutrophiles-7.4-7.5
Acidophiles- like acidic living conditions pH of <7
Alkaliphiles- Like basic living conditions pH or >8
Halophiles v Halotolerant
Halophiles love salt and require high levels to survive
Halotolerant do not need salt to survive but can survive in areas where salt is present
heterotroph v autotroph
heterotrophs cannot make their own nutrients and must break down organic substances to do so
autotrophs can create the nutrients they need using only Co2
Nitrogen Fixation
The ability to pull nitrogen from the air and break it down into ammonia and return it to the soil for use
What are the major components needed to synthesize cellular material?
nitrogen, oxygen, glucose, amino acids
Phototrophs v Chemotrophs
Phototrophs synthesize their energy from sunlight
Chemotrophs synthesize their energy from oxidation of certain compounds
Fastidious Bacteria
Bacteria that need specific nutrients to grow, and will not grow if certain conditions are not met
Growth Factors
Proteins, amino acid, or vitamins that cells need to grow but cannot synthesize themselves
Complex v Chemically defined media
Complex media is media that has an array of nutrients in it.
Chemically defined media has very specific type and amount of nutrients dissolved in it
MacConkey Agar and Selective Media
Selective media encourages the growth of certain bacteria while inhibiting the growth of others
MacConkey Agar= Differentiates between Lactose fermenting and Non Lactose Fermenting bacteria gram negative bacteria
Differential Media
Used to identify bacteria that are closely related but not the same
Capnophiles
Bacteria that thrive and replicate in the presence of CO2
Enrichment Agar
Agar that has a multitude of different nutrients in it to promote the growth of a diverse amount of bacteria
