Culturing Flashcards
Define a closed sysetm
A system which has a finite amount of resorces in it. will follow a distint trend
how do bacteria duplicate
Binary fission
- Origon of DNA duplicates
- Replicates DNA and 1 origon on each side of cell
- Cells seperate to create two bacteria
What has the speed of bacterial growth caused
speed has led to eviroemtnal dominance across all domains
What are the four phases of closed batch cultures
Feast and famine trend
Lag phase: cells are adapting to new enviroemnt regulating genes. Legth of this phase is dependant on how simlar the culture enviroment is to the prevous enviroment
Exponential phase: growth is exponential, doubling at even time intervals ideaky
Statonary phase: Dynamic equilibrium is reached where all nutriance for new cell replication comes from lycised cells = cryptic growth
Death plase: conditions become worse, equilibrium skews towards death, total population declines
What are the requirements for bacterial growth
- what nutriance
Sorce of carbon
Sorce of energy
Reducing power - to move energy around
What are the two sorces of energy and carbon, name the shorthands for them
Energy:
light = photo
Carbon = chemo
Carbon:
CO2 = Auto
Organic compounds = Hetro
ended in troph
What is the name of a cell which produces their own energy
Autotrophs
What is the process of building up and breaking down in a cell
Catabolism = breaking down of substance for energy
Anabolism = Creating macromoleules
What is a microbiome and how do cells interact
An enviroment with many different cells interacting
Auxotrophs = cells which cannot produce an essental resorce = cross-feeding required
Auxotrophs rely on other cells for resorces
Can use biproduces or cooperation
What are pros and cons of culture system
Pros: Variables can be modified
information about bacterial phenotypes
Cons: We can only culture a very small number of bacteria
What are the pros and cons of a culture independant systems
Pros: give information of the genoypes involved, more relivant to the natural enviroment
Cons: Exspensive, cant manipulate the conditions
What is an auxotroph
A bacteria which doesnt have an essental gene
cannot be grown in culture without limiting factors being added
Uses cross feeding to live
What is microbial ecology
The study of the inetrrelationships between microorganisms in their natural envrioment
What do culture independant methods use to determine the presense of a bacteria
16s rRNA section of DNA which is very specific to each bacteria
what is cross feeding
and its second name
Syntrophy
the process by which resorces are shared between bacteria, relied upon for auxotrophs
Can be 1 or 2 way
Bi products or cooperative
