Bacterial Growth & Nutrition

unit: gram per liter

macroelements

components of carbs, lipids, proteins, nucleic acids that include C, H, O, N, S, P

macroelements

required for skeleton or backbone of all organic molecules

carbon

maintain pH and form bonds in macromolecules, prime force in redox rxns

hydrogen

role in structural and enzymatic functions of cell, as electron acceptor in aerobic respiration

oxygen

part of amino acids that form proteins, facilitate cell synthesis

nitrogen

for biosynthesis of amino acids (cysteine, methionine), vitamins (thiamine, biotin), protein structure linkage (disulfide bond)

sulfur

synthesis of nucleic acids and ATP

phosphorus

unit: milligrams per liter, exist as cations

microelements

protein synthesis and membrane function

potassium

contributes to heat resistance by bacterial endospores

calcium

cofactor for enzymes, complexes with ATP, stabilize ribosomes and cell membranes

magnesium

part of cytochrome and cofactor for enzymes and electron-carrying proteins

iron

unit: microgram per liter

trace elements

part of enzymes and cofactors that aid in catalysis of reactions and maintenance of protein structure

trace elements

required to activate enzymes and naturally present in tap water

trace elements

organic compounds that are essential cell components and cannot be synthesized by organism

growth factors

carbon

macroelement

hydrogen

macroelement

oxygen

macroelement

nitrogen

macroelement

sulfur

macroelement

phosphorus

macroelement

calcium

microelement

iron

microelement

magnesium

microelement

potassium

microelement

manganese

trace element

nickel

trace element

molybdenum

trace element

copper

trace element

cobalt

trace element

zinc

trace element

oxidize organic form of carbon

chemoheterotroph

oxidize inorganic compounds

chemoautotroph

use organic carbon

heterotroph

use CO2 as sole source of carbon

autotroph

energy source (light), carbon source (CO2)

photoautotroph

energy source (light), carbon source (organic compound)

photoheterotroph

energy source (inorganic compound), carbon source (CO2)

chemoautotroph

energy source (organic compound), carbon source (organic compound)

chemoheterotroph

affect growth rate, type of reproduction, morphology, metabolism, and nutritional requirement

temperature

at most favorable temp, number of cell divisions per hour doubles for every temp increase of 10 degrees C

true

at most favorable temp, number of cell divisions per hour doubles for every temp increase of 5 degrees C

false

higher temp, faster growth rate

true

lower temp, faster growth rate

false

cold-loving, able to grow in 0C, average temp is 15-20C

psychrophile

psychrophile variant that survive 10-15C can grow at 0C but optimal is 25-37, example is Listeria monocytogenes

psychrotroph

grow at 40-85C, mostly prokaryotes, found in volcanic areas, compost heaps, hot springs

thermophile

grow at 70-110C, members of Archaea, grow near hydrothermal vents at great depths in ocean

hyperthermophile

water availability depends on presence in atmosphere or in solution or substance

water activity

higher solute, lower water activity

true

lower solute, lower water activity

false

common solute in nature that occurs over wide concentration range

NaCl

require some NaCl for growth

halophile

require 1-6% salt

mild halophile

require 6-15% salt

moderate halophile

require 15-30% salt

extreme halophile

grow at moderate salt concentration, grow best in absence of NaCl

halotolerant

tolerate hypertonic environment whether salt, sugar, or other solute

osmophile

persist in dry environment, subject to desiccation

xerophile

require oxygen for growth, use oxygen as final acceptor in aerobic respiration

aerobe

switch between anaerobic and aerobic metabolism, do not require oxygen

facultative anaerobe

indifferent to oxygen, can grow with oxygen but do not use it as hydrogen acceptor

aerotolerant anaerobe

do not require nor use oxygen, poisoned by oxygen

obligate anaerobe

converts H2O2 to molecular oxygen and water

catalase

convert H2O2 to water

peroxidase

grow best at oxygen level between 1-15%, use it for energy-yielding reactions

microaerophilic

force with which water moves through cytoplasmic membrane from solution with low concentration of solute to a high solute concentration

osmotic pressure

pressure exerted on cells by weight of water resting on top of them

hydrostatic pressure

water from inside goes out

hypertonic

higher solute concentration outside

hypertonic

shrinks cell

hypertonic

water outside goes in

hypotonic

higher solute concentration inside

hypotonic

swell or ruptures cell

hypotonic

pressure-dependent, dies in low hydrostatic pressure as gas vesicles expand upon decompression and cells rupture

barophile

in glass container

in vitro

in living cells or organisms

in vivo

has a carbon and energy source, organic source of nitrogen and various inogranic salts in buffered aqueous solution

simple synthetic media

simple media components with amino acids, purines, pyrimidines, and growth factors

complex synthetic media

support growth of many bacteria, different species show different characteristic colonies and morphologies

non selective media

eliminate or reduce large numbers of irrelevant bacteria, incorporation of inhibitory agent

selective media

inhibitory agent that selects for gram positive over gram negative

sodium azide

inhibitory agent that selects for gram negative enteric and inhibit gram negative mucosal and most gram positive

bile salts

inhibitory agent that inhibit gram negative

colistin and nalidixic acid

media with bile that selects for gram-negative rods

MacConkey agar

media with 7.5% salt allowing Staphylococci to grow but inhibit other microbes

mannitol salt agar

allow separation of different groups of bacteria based on variations in colony size or color using dyes as pH indicators

differential media

lactose fermenters produce pink colonies in MacConkey agar like E. coli

true

lactose fermenters produce white colonies in MacConkey agar like E. coli

false

wider the area of clearing observed, the better the performance of the antibiotic in killing the organism

true

wider the area of clearing observed, the organism is said to be resistant to the antibiotic

false

cell population arising from single cell

pure culture

small volume of dilute microbial suspension is transferred to center of agar plate and spread evenly over surface with a sterile bent-glass rod

spread plate

microbial mixture is transferred to edge of an agar plate with an inoculating loop or swab and streaked out over the surface in several patterns

streak plate

sample is diluted several times to reduce population to obtain separate colonies upon plating

pour plate

colony growth is much slower in center

true

colony growth is much faster in center

false

population is temporarily unchanged, no cell division, bacteria is still adapting to medium, no growth, increase metabolic activity

lag phase