L22: Pigments Flashcards
Discuss light penetration vs depth
longer wavelengths dont penetrate as deepy as shorter ones, they deeper they penetrate the stronger they are (short wavelengths are more powerful)
*cyanobacteria absorbs shorter wavelegnths, can also absorb low
*deep organisms like prochlorococcus have pigments that absorb short wavelengths
What are photosynthetic pigements
*pigments to absorb light over range of wavelengths of available light in their specific niche
*chlorophylls, bacteriochlorophylls, carotenoids, phycobiliproteins
What is the black thing in soil column, what can it the colours depends on
black is sulphate input
changes with tide, bringing nutrients and other things can affect stratification. different nutrients, different niche, different colour
What is the peach colour
peach layer below purple are both purple sulfur of different niches
draw the wavelengths of cyano, PB and GB
draw, slide 76
In words, describe distribution of phototrophs by depth
UPPER ZONE
Surface: cyanobacteria, Chl a harvests shortest wavelengths of light
=>have gas vacules for buyancu, higher energy, PS2 can oxidise H2)
LOWER ZONE
Middle: PB, BchlA+B harvest longest wavelengths of light, long wavelengths cant penetrate any deeper => this is the limit for those organisms
deepest: GB, Bchl c, d, e, g harvest midrange wavelengths of light, the wavelengths penetrate deeper than those of PB meaning GB can be deeper than PS, in H2S zone away from O2
overall lower zone
=>PS absorb lower energy WLs so PS cannot oxidise H20, microbes can support
=>purple sulfur microbes support hetetrophs in that zone
=>settling organic matter supplies non phototrophs in deeper zones
What are key environmental factors and how do they impact microbial physiology
trOphs
lower tolernace limit /// upper tolerance limit
temperature: -12C /// 110C
redox potenital: -450 /// 850
ph 0 /// 13
hydrostatic pressure 0 /// 1400
salinity 0 /// saturated
methanogenic bacteria
most e-negative and aneorbic
What are crypoendothilic bacteria
hidden inside rocks
light can penetrate so it allows phototrophs / other microbes to grow, rocks can also retain small water (serves as protection)
lots of mineral ozidation
Associate environmental ranges with bacteria type
psychrophileS: -15 to below 10
mesophiles: 4 to 50
thermophiles: 40 to 100
a meso optimal would be minima for psychro
How do extreme psychrophiles survive
metabolic activity in brine veins between ice crystal
brines have salts, concentrated organic compounds, can be colder than -15
discuss extremes of pH
usually between 4 - 9 but can go to extremes
acidophiles, neutrophiles and alkaliphiles
Is vinegar made aerobically or anaerobically
Vinger = acetic acid from aerobic oxidation of ethanol by Acetobacter which decreases pH to 3, can also be produced via aerobic respiration via fermentation
high pressure high temp zones
thermal vents
What happens with acid mine drainage, what are ecological effects
coal, ores, tailings have reduced sulfur compounds like iron pyrate FeS2
=>they become spontaneously oxidised by O2 and by microbes acid mine drainage reactions, this drops pH to 4.5
=>iron bacteria active until too acidic, below 3.5 acidophiles take over
=>becomes oxidised to sulfuric acid H2SO4 and toxic metallic compounds known as Yellow boy
=> yellow boy becomes exposed to air
Ecological effects: H2O, iron compounds, ferric hydroxide precipitates run off into streams, kills all life, water undrinkable
