Physiological and immunological methods Flashcards
What are Activity measurements
estimates of the physiological reactions occuring
what do activity measurements help define?
the structure and function of the microbioal ecosystem
what does HPLC stand for
high-pressure liquid chromatography
what happens in HPLC
sample is dissolved and forced under pressure through a column packed with a stationary material
what is respiration
consumption of O2 or electron pair acceptor
what is biochemical oxygen demand
measures the amount of organic matter that can be oxidized by the microbes present in the water
what is BOD used for
to track the reduction of organic and inorganic materials in wastewater by treatment facilities
What is chemical oxygen demand
strong oxidizer oxidizes the organic matter into CO2
What is COD used for?
rapid measure of water quality
what is microcosm?
a sample is typically incubated in a sealed, airtight enclosure
What are two ways CO2 and O2 are measured
-samples are drawn using a gastight syringe and injected into a gas chromatograph
-trap CO2 produced in a trap with solution of NaOH
What are some difficulties when measuring respiration in soils and sediments using a respiration chamber with an infrared gas analyzer?
variation of soil moisture, temp, etc
also hard to separate the contributions of heterotrophic bacteria and plant roots
what do extracellular enzymes do?
break down N-, P- or S- containing organic compounds
What are microsensors?
glass needles containing a sensing mechanism that allow to measure many chemical species including pH, O2, NO2-, NO3-, N2O, CO2, H2 and H2S
True or false: Microsensors can only measure one analyte in a microbial habitat
false; they can simultaneously measure several
Why can NO3- not be measured electrochemically in seawater?
high concentrations of salts
What is an isotope
an element with a varying number of neutrons
what is the result of radioactive decay on isotopes
unstable isotopes break down
when are radioisotoepes used?
used when high sensitivity is required
what kind of isotopes are used in microbial ecology to yield information on microbial activities
radioactive and stable isotopes
what kind of isotopes are used in microbial ecology to yield information on microbial activities
radioactive and stable isotopes
What stable isotope elements are used for studying microbial ecology?
C, S, N
why are C, S, and N used for isotopes?
their abundance changes when they are metabolized because enzymes favor the lighter isotope
what is isotopic fractionation?
measures if a particular transformation has been catalyzed by microbes
what did isotopic fractionation help prove?
there is organic C in 3.5 billion years old rocks showing that autotrophic life existed at that time
What is stable isotope probing( SIP )?
method of coupling diversity to activity through labeling of community DNA with C, N or O
What has SIP been used for?
studying phylogeny and metabolism of methylotrophs
What is Secondary Ion Mass Spectrometry?
a vaporized sample is bombarded by high-energy electrons which create cations by knowing elections off atoms. These cations are accelerated through electric plates.
what does SIMS help show?
mass to charge ratio and creates a mass spectrum
What is Microautoradiography-FISH
determines which organisms in a natural sample are metabolizing a particular radiolabeled substance
what are antibodies also known as
immunoglobulines
what are antibodies
proteins that bind to specific cellular structures (antigens)
what is the most common circulating antibody
IgG
Is polyclonal antibodies or monoclonal antibodies preferable
monoclonal antibodies
what is the most significant impact antibody-based methods have done?
detection in foodborne pathogens and thier toxins
What is Reversed passive latex agglutination used to detect?
microbial toxins
How does a reversed passive latex agglutination work?
if there are particles, the particles clump together and have a diffused appearance. if there is no antigen, there will be a tight dot. Think of hemagglutinin assay
what are lateral flow tests
an aliquot of enrichment culture is wicked through a chromatographic matrix to a reaction area containing antibodies conjugated to precipitable material.
what are lateral flow tests used for?
rapid diagnosis or HIV/AIDs, strep throat, flu
these look like covid tests that have the little strip
what is immunofluorescence
uses antibodies conjugated with fluorescent dyes to diagnose and research
What is Enzyme-linked immunosorbent assay
uses antibodies-coated microtiter plates to capture the target antigen
What does ELISA stand for?
enzyme-linked immunosorbent assay
