micro exam 3

i am cry

temperature, pH, water, oxygen

What 4 factors affect microbial growth

cardinal temperatures

maximum, minimum, and optimum temp for microbes

Psychrophiles

cold loving, 0-20*C

Fragillaria

optimum 7*C

Chlamydomonas (algae)

pink snow

Facultative psychrophile

aka psychrotolerant, usually grow 25-30*C, but can grow lower

Thermophiles

optimum temps 45*C or higher

hyperthermophiles

greater than 80*C, mainly archae, desert soils, hotsprings, hydrothermal vents

higher temps than eukaryotes

Prokaryotes grow at ___ temps than eukaryotes

65*c

eukaryotes max temp

higher temps than photosynthetic

nonphotosynthetic organisms are able to grow at ___ temps than photosynthetic organisms

higher temps than more complex

structurally less complex organisms grow at ___ temps than more complex organisms

Thermus aquaticus

taq polymerase,

higher concentrations of unsaturated fats

psychrophiles have ___ concentrations of unsaturated fats

thermophiles have ___ concentrations of saturated fats

higher concentrations of saturated fats

Mesophiles

optimum temp is 15-45*C

pH 5-9

most natural environments have a ph of what?

thermoacidophiles

hot springs

halophiles

salt loving

barophiles

organisms that thrive under high pressure

obligate aerovbe

requires oxygen

microaerophile

requires oxygen but at less concentrations

anaerobe

does not require oxygen

obligate anaerobe

harmed by oxygen

facultative anaerobe

survives with oxygen, but can exist without it

aerotolerant anaerobe

tolerates oxygen but does not need it for growth, fermenters

oxygen toxicity

oxidizing agent, small amounts formed during cellular respirations

superoxide ion

O2 + e- —> O2- accumulates in anaerobes exposed to O2 inactivates cell components

superoxide dismutase

O2- + O2- + 2H+ -—> H2O2 + O2

Catalase

2H2O2 —> O2 + 2H2O

peroxidase

NADH + 2H+ + H2O2 —> 2H2O + NAD+

aerobes have what enzymes

superoxide dismutate, catalase, peroxidase

facultative anaerobes have what enzymes

catalase sometimes absent

aerotolerant have what enzymes

superoxide dismutase, lack catalase

obligate anaerobes have what enzymes

lack all 3

agar

slime of red algae, metabolically inert, solidifies at 42*C

Synthetic media

chemically defined, exact composition and ingredient weight

complex media

natural, exact compostions not known, beef extract, yeast extract, nutrient, TSA, corn meal agar, potato dextrose agar

selective medium

suppresses growth of unwanted bacteria, select for desired bacteria, mannitol salts agar MSA, selects for S. aureus

Differential medium

makes growth of one bacterial species look different from another, blood agar, some bacteria cause hemolysis, MSA low pH, phenol red from red to yellow

anaerobic medium

removes oxygen, sodium thioglycolate combines with oxygen, special growth chambers

enrichment medium

broth, selective medium, increase low numbers of desired bacterium from mixed environmental of clinical sample

binary fission

divide to 2 cells

DNA replication

is bidirectional

MreB protein and shape

spiral inside periphery of cell in rods, directs cell wall synthesis to contract, cocci lack MreB protein

Crescentin, caulobacter crescentus

vibrio, long concave curvature, inhibits growth

N = N₀2ⁿ

N= end count, N0= beginning count, n= # of generations

how to find n

n= 3.3(logN-logN0)

g=t/n

how to find generation time g

biofilm

slime encases aggregation of microbiota

intracellular cyclic di-guanosine monophosphate

triggers connection and attachment

matrix

made of polysaccharide proteins, glycoproteins, glycolipids, DNA, extracellular polymeric substances

what do biofilms offer?

UV light, antibiotics, antimicrobial, resist phagocytosis

Vibrio cholerae

cholera, oceans, low densities, teeth, pipes, oil pipes, used in sewage treatment

bacteriostatic

bacteriocidal

bacteriolytic

decimal reduction time

food industry, time for ten-fold reduction in living cells, 10% remain

pasteurization

62.8*C for 30 min, 72*C for 15 seconds, milkd

dry heat

hot air, 160*C, 2 hrs, needed to kill endospores, flaming

lowering temps

preservation, depress metabolic rates, bacteriostasis, refrigeration to 4*C, freezing, eukaryotic cells destroyed, spores survive

dessication

preservation of drying, jerky, dried grains

osmotic pressure

salt, sugar

radiation

ionizing radiation to form hydroxyl radicals to damage cell DNA, gamma rays, x rats, penetrating, spices, meats, veggies, milk, heat sensitive surgical materials

nonionizing radiation

ultra violet, damages DNA, not penetrating, germicidal lamps, surface sterilization

filtration

filters with 0.2 micrometer pores, HEPA filter

disinfectant

chemical applied to object to kill

sanitizer

reduce, may not eliminate microbial numbers

antiseptic

applied to tissue, kills or inhibit, bacteriostatis, bactericidal

minimum inhibitory concentration

smallest amount of an agent needed to inhibit growth of a test organism

stromatoliites

fossilized microbrial mats

hydrogen hypothesis

hypothesis suggesting that life originated from hydrogen-producing microorganisms, emphasizing the role of hydrogen in early cellular metabolism.

oligodynamic action

the mechanism by which small amounts of heavy metals inhibit microbial growth.

surfactants

compounds that reduce surface tension, allowing easier mixing and interaction of liquids, often used in detergents and emulsifiers.

diplomonads

protist, 2 nuclei of unequal size, mitosomes reduced mitochondria, lack ETC, CAC, genes, flagellated

Giardia intestinalis

lamblia, diplomonad, gastroenteritis, 30,000 cases, form cysts: resistant structures

Parabasalids

parabasal body, connects flagellum to golgi app. lack mitochondria, have hydrogenosomes, anaerobic,

euglenozoans

chloroplasts present or absent, autotrophs/heterotrophs, no pathogens

euglenids

Euglena, pellicle, stigma, two flagella, one emergent, or inside, paramylon for storage of B-1,3

kinetoplastids

mass of circular DNA in the single mitochondria, kDNA, lack chloroplasts

Trypanosoma brucci

african sleeping sickness, tse-tse fly, subsaharan

T. cruz

Chagas, kissing bugs in latin america

Leishmania

skin, sandflies

Alveolates

sacs under cytoplasmic membrane

ciliates

paramecium, macro, micronucleus, conjugation for sexual repro

Balantidium coli

gastroenteritis

Apicomplexans

non-motile, Plasmodium: malaria, P. falciparum most lethal, P. vivax most common

sickle cell anemia

heterozygous, resistant to malaria in area where common

Toxoplasma gondii

cat feces, undercooked meat, gasterenteritis

Dinoflagellates

photoautotrophs, 2 flagella, dino-whirled, armored from cellulase plates, pigment: carotenoids red to brown, endosymbiosis with corals, bioluminescence, red tide, accumulates in shellfish and passes toxins to humans

Pfiesteria piscidia

dinoflagellate accumulates in fish and leads to death

Amoebozoa

pseudopodia, amoeba

Entamoeba histolytica

amoebic dysentery, amebiasis

Naegleria fowler

primary amoebic: meningoencephalitis (PAM) swimming, nose to brain, cyst, trophozoite, flagellate

chlorophyta

green algae, chlorophyll a and b, starch, cellulose walls, rise to land plants

Rhudophyta

red algae, chlorophyll a and d, phycoerythrin: red, macroscopic, nori, carrageenan reacts with milk protein to form gel

Gelidium

source of agar

Stramenophiles

photosynthetic or not, flagellate

Phaeophyta

brown algae, kelps, macroscopic, fucoxanthin golden brown, laminarin storage, algin slime from surface used as thickening agent

Diatoms

Bacillariophyta, fucoxanthin carotenoid, golden brown, walls have SiO2 glass, radial bilateral, fats, oils, chrysolaminarin for reserve, free floating,