What is DNA stable isotope probing?
DNA stable-isotope probing (DNA-SIP) is a powerful technique for identifying active microorganisms that assimilate particular carbon substrates and nutrients into cellular biomass.
How does stable isotope probing work?
Stable-isotope probing (SIP) is a technique in microbial ecology for tracing uptake of nutrients in biogeochemical cycling by microorganisms. A substrate is enriched with a heavier stable isotope that is consumed by the organisms to be studied.
What is an example of a stable isotope probe used to study soil microbes?
3.3. Stable isotope probing (SIP) involves offering a stable isotope (e.g., 13C)-labeled substrate to microbial communities whose utilization is of interest to decipher a key biogeochemical process (Dumont & Murrell, 2005; Wellington, Berry, & Krsek, 2003).
What is considered a stable isotope?
Stable isotopes are chemical isotopes that are not radioactive (they have not been observed to decay, though a few of them may be theoretically unstable with exceedingly long half-lives). By this definition, there are 256 known stable isotopes of the 80 elements which have one or more stable isotopes.
What happens after the DNA is unzipped?
DNA helicase continues to unwind the DNA forming a structure called the replication fork, which is named for the forked appearance of the two strands of DNA as they are unzipped apart. The process of breaking the hydrogen bonds between the nucleotide base pairs in double-stranded DNA requires energy.
What have the developments in the history of metagenomics contributed to our understanding of?
The first metagenomic sampling. 16S rRNA gene sequencing studies expanded our understanding of microbial diversity and ecology, and ushered in the era of culture-independent studies. This era was catalyzed by improved PCR primers and economic Sanger sequencing.
How do you determine if an isotope is stable or unstable?
An unstable isotope emits some kind of radiation, that is it is radioactive. A stable isotope is one that does not emit radiation, or, if it does its half-life is too long to have been measured.
What’s the difference between a stable and unstable isotope?
Stable isotopes are naturally occurring forms of elements that are non-radioactive. Unstable isotopes are atoms having unstable nuclei. Therefore, these elements undergo radioactivity. This is the main difference between stable and unstable isotopes.
What are two unzipped strands of DNA called?
The first step in DNA replication is to separate or unzip the two strands of the double helix. The enzyme in charge of this is called a helicase (because it unwinds the helix). The point where the double helix is opened up and the DNA is copied is called a replication fork.
What is unzipped DNA called?
This separated, independent structure with all base pairs unzipped is called ssDNA. The DNA unzipping and the DNA unwinding result in a structural transformation from dsDNA to ssDNA.
What is metagenomic DNA?
Metagenomics is defined as the direct genetic analysis of genomes contained with an environmental sample. The field initially started with the cloning of environmental DNA, followed by functional expression screening [1], and was then quickly complemented by direct random shotgun sequencing of environmental DNA [2,3].
How do you determine stable isotopes?
Isotopes of elements with atomic number (Z) less than 20 and with a neutron to proton ratio of close to 1 are more likely to be stable if the nucleus contains an even number of protons and an even number of neutrons.
What stabilizes the DNA molecule during replication?
Proteins in DNA Replication Single-strand DNA- binding proteins (SSBPs): These proteins stabilize the individual strands of DNA to prevent them from reconnecting.
What is the junction between separated strands called?
The junction between separated strands is called the. replication fork.
Is metagenomics whole genome sequencing?
Metagenomics is a culture-independent method that allows the identification and characterization of organisms from all kinds of samples. Whole-genome shotgun sequencing analyses the total DNA of a chosen sample to determine the presence of micro-organisms from all domains of life and their genomic content.
What is the difference between metagenomics and metatranscriptomics?
While metagenomics focuses on studying the genomic content and on identifying which microbes are present within a community, metatranscriptomics can be used to study the diversity of the active genes within such community, to quantify their expression levels and to monitor how these levels change in different …