Why is it not safe to assume that two organisms with same GC content belong to same species?

Answer: Answer. It has been observed that there is a correlation between GC content and relatedness between species. This means there is a similarity in GC content in closely relates species.

Why is it important to note all the cultural characteristics in the identification of bacteria?

When grown on a variety of media, microorganisms will exhibit the difference in the microscopic appearance of their broth. These differences are called cultural characteristics and are used as a basis for separating microorganism into taxonomic groups.

Why is the identification of bacterial unknowns important?

WHY IS THE IDENTIFICATION OF BACTERIAL UNKNOWNS IMPORTANT? Microbiologists must identify bacterial isolates for several practical reasons: • Medical diagnostics — identifying a pathogen isolated from a patient. Food industry — identifying a microbial contaminant responsible for food spoilage.

Why is it important to properly identify microorganisms?

Bacteria that are normal flora are important symbionts of the human body, most of which cause no ill effects and some, which are actually beneficial to human health. Thus, microbiologists use characteristic biochemicalactivities to more specifically identify bacterial species.

What is being compared during DNA hybridization studies of two bacteria?

DNA–DNA hybridization was once used as a primary method to distinguish bacterial species; a similarity value greater than 70\% and ≤ 5 ºC in ΔTm in the stability of the heteroduplex is described as indicating that the compared strains belonged to the same species.

Do all organisms have the same GC content?

GC content is found to be variable with different organisms, the process of which is envisaged to be contributed to by variation in selection, mutational bias, and biased recombination-associated DNA repair. The average GC-content in human genomes ranges from 35\% to 60\% across 100-Kb fragments, with a mean of 41\%.

Why is it important not to contaminate a pure culture?

A pure culture contains only one genus and species of organism. When isolating an organism for research purposes it is important that the pure culture is not contaminated. Not only can unwanted species contaminate a pure culture and yield incorrect results but they also may be pathogenic and facilitate disease growth.

Why it is important to isolate microorganism in the laboratory?

Isolating a single bacterium species is the first step in identifying the bacteria possibly responsible for a disease process. The bacteria we work with are also very easy to culture in the lab.

Which two characteristics are the most important to identify when starting to identify an unknown bacteria?

Begin the process of identifying unknown bacteria by observing their physical characteristics, such as cell wall, shape and linkages. Use standard laboratory procedures, like cell staining, culturing and DNA sequencing to further narrow down your identification.

What are the importance of using differential culture media in identifying unknown bacteria?

The differential media make it easy to distinguish colonies of different bacteria by a change in the color of the colonies or the color of the medium.

What you need to know about microorganisms?

Microbes are organisms that are too small to be seen without using a microscope, so they include things like bacteria, archaea, and single cell eukaryotes — cells that have a nucleus, like an amoeba or a paramecium. Microbes come in a huge variety of shapes — everything from rods to spheres, even corkscrew shapes.

What are the drawbacks of DNA-DNA hybridization?

Major disadvantages are the laborious nature of pairwise cross-hybridizations, the requirement for isotope use, and the impossibility of establishing a central database. Here, we propose a new approach to identify and type bacteria based on genomic DNA-DNA similarity that eliminates the above disadvantages.