lecture 2-23 to post Flashcards
what are community’s built from
community’s are built from a variety of guilds, guilds are metabolically related organisms(co-metabolism)
what is a niche
a niche defines the nutrient and enovoirmental conditions which a organisms needs to survive
niche vs microenvoirment
niche is the role which the organisms plays in the micoenvoirment
what is a microenvoirment
where a orgnisum is and what it metabolises
where are extended periods of exponential growth rare to find in nature
b/c in nature a constant flow of nutrients at a stable pH and constant ideal temp is very rare
what is the form in which microbs undergo optimal growth in
The state which is most favorable by all microbes in attached to a surface in a biofilm
for microbes to attach to a surface the surface first needs to be pioneered, this is done by pioneer orgnaiusms whuch are able to metabolize raw nutrients creating by products which other organism’s can use to grow and develop .
significance of biofilms
They are the main cause fo dental disase, they can cause reduction of waterflow in pipes due to buildup on the pipe wall, they can decrease the quality of potable water, they are also the main cause of infections associated with artificial implants
how can biofilms be beneficial
they can filter water such as waste water
They can leach low grade ores
what are the top 2 things which microbes compete for
Nutrients and space
what is antagonism
a form of competition where one microorganioganism inhibits the growth or limits metabolism of other microorganisms through exterior of a inhibitor or toxic metabolite
what is syntropy
where 2 or more microbes worth together to carry out a transformation which neither can do alone these organisums will typically share the same microenvoirment
Examples include
nitrification
sulfate
sulfide
Primary relationships between microbs
Commensalism–> one pop benefits and the other is not effects(+ or neutral)
Co-metabolism–> type of commensalism which 2 work together to create a transformation
Synergism–> both benefit this is a form of mutualism
where are the biggest C reserves found?
earths crust
humus
land plants
what is humus
a complex mixture of decomposing organic material
at is the largest contributor of CO2
Microbial decomposition
what are the 2 ways which new organic carbon is formed (carbon which can be used by organisms
Oxygenic photosynthesis
Chemosynthesis which is fixation of CO2 by chemolithotrophs
what are the major oxidation states of carbon
CH4 methane which is done via methanogens
CO2 which is done via chemoorganotrophs
the production of one or the other depends on the presence of either methanogens or chemoorganotrophs when humus is decomposed
what is the process of methanogenesis and what enzyme is involved
this is the formation of methane via
CO2+4H–> CH4+2H2O
mediated via enzyme methyl reductases
methanogens
anaerobic archaebacteria
these have a very narrow substrate range so cooperation w other organisms is needed to meet nutrient needs
where are methanogenesis most likely to be found (habitat)
Swamps marshes and anaerobic microenvironments
they are often found in these water logged environments bc they have a high aw while remaining anerobic
which hydrocarbons are not degraded anaerobically
lignin and aliphatic saturated hydrocarbons
methanotrophs
are a specialized subset or methylotrophs which oxidize methane
why type of carbon compounds do methylotrophs use
They utilize 1-C compounds as there source of both energy and carbon
what is the primary role of the nitrogen cycle
to convert inorganic C to useable organic forms which can be used by other organisms
which organisms can preform nitrification
NH4–> NO3
nitrosomonas
denitrification
NO3–> N2
Psedomonas
N2 fixation
N2+8H–> NH3+H2
free living cyanobacteria
anerobic Rhizobium
Symbiotic Frankia
Ammonification
organic N–> NH4
done by many organisms
where are the biggest nitrogen pools
the atmosphere=80%N2
Fertile soil which contains 30,000 tons per/acre
Nitrification
This is the conversion of ammonia to nitrate by nitrifying microbes
Denitrification
Conversion of nitrate to nitrous oxide or N2 via denitrifies(nitate consumption) which is carried out under anerobic conditions
what is the cause for the loss of nitrogen from the soil
Denitrification as it facilities the formation of gaseous N2 which causes loss of nitrogen from the soil this is why we have crop rotation as plants such as pea plants have nitrogen fixing bacteria which have a mutualist relationship with the pea plant thus fixing the bacteria into the ground into organic bacteria
Ammonification what is it
Decomposition of organic nitrogen compounds creating ammonia as a by product
what is nitrogen fixation and what organisms carry it out
Utilization of N2 as a source of nitrogen where N2 is converted to ammonia via aerobic chemoorganotrophs such as azotobacter ssp
root nodule bacteria what is it and how does it occur
this is a symbiosis between leguminous plants and gram - bacteria
- recongition and attachment
- invasion of root hair
3.travel via infection thread
formation of bacteriods
continnuwed plant cell/bacterial cell division
leghemoglobin
contorls O2 binding in Fe protein and controls the O2 levels in root nodual which protects against nitrogenase (oxygen buffer)
what are bacteroids
the resluting product from rapid multipulocation of bacteria within the plant cell these bacteria often become swollen and misshapen into branced forms
what is symbiosome
these are the bacteriods which are surrounded by proteions of the plant cell membrane
what is Assimilatory nitrate reduction
this is the pathway present in all bacteria which reduce nitrate to ammonia
What is dissimilatory nitrate reduction
this is a type of nitrate respiration which is a aerobic process which occurs when oxygen levels are low producing nitrite ammonia and N2
