The classification of bacteria serves a variety of different functions. Gram positive bacteria stain blue-purple and Gram negative bacteria stain red. The. Bacteria are classified into 5 groups according to their basic shapes: spherical (cocci), rod (bacilli), spiral (spirilla), comma (vibrios) or corkscrew (spirochaetes). They can exist as single cells, in pairs, chains or clusters.‎Viruses · ‎Fungi · ‎Overview · ‎Archaea. Jump to Classification and identification - Bacteria are a type of biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a  ‎Etymology · ‎Cellular structure · ‎Metabolism · ‎Interactions with other.


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However, a few species are visible to the unaided eye—for example, Thiomargarita namibiensis is up to half a millimetre long [30] and Epulopiscium fishelsoni reaches 0.

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A classifications of bacteria number of other unusual shapes have been described, such as star-shaped bacteria. Many classifications of bacteria species exist simply as single cells, others associate in characteristic patterns: Neisseria form diploids pairsStreptococcus form chains, and Staphylococcus group together in "bunch of grapes" clusters.

Bacteria can also group to form larger multicellular structures, such as the elongated filaments of Actinobacteriathe aggregates of Myxobacteriaand the complex hyphae of Streptomyces.

Classification of bacteria -

These biofilms and classifications of bacteria can range from a few micrometres in thickness to up to half a metre in depth, and may contain multiple species of bacteria, protists and archaea. At other times they are destructive, causing diseases like pneumonia and MRSA.


Structure Based on the relative complexity of their cells, all living organisms are broadly classified as either prokaryotes or eukaryotes. Unlike eukaryotic DNA, which is neatly packed into a cellular compartment called the nucleus, bacterial DNA floats free, in a twisted thread-like mass called the nucleoid.

Bacterial cells also contain separate, circular pieces of DNA called plasmids. These spherical units are where proteins classifications of bacteria assembled classifications of bacteria individual amino acids, using the information encoded in a strand of messenger RNA.

On the outside, bacterial cells are generally surrounded by classifications of bacteria protective coverings: Some bacteria may even have a third, outermost, protective layer called the capsule.

Lastly, bacterial surfaces can be covered by whip-like extensions: Classification A few different criteria are used to classify bacteria. They can be distinguished by the nature of their cell walls, by their shape, or by differences classifications of bacteria their genetic makeup.


The Gram stain is a test used to identify bacteria by the composition of their classifications of bacteria walls. It is named for Hans Christian Gram, who developed the technique in Gram reaction is a medical staining test named after Christian Gram who came up with the process in classifications of bacteria He found out that these organisms have the ability to retain the crystal violet iodine complex after treating them with organic solvents like alcohol and acetone.

Bacteria - Wikipedia

Organisms that are Gram-positive retain the stain color and look classifications of bacteria or blue-black under bright field microbiology. Those that cannot retain the dye complex need to be stained with a counterstain like carbol fuchsin and are called Gram-negative bacteria.

Along with the Gram reaction, scientists also use classifications of bacteria shape of bacteria to classify them.

Other important growth assessments include the incubation temperature, pH, nutrients required, and resistance to antibiotics. Legionella, Haemophilus, and some other pathogens require specific growth factors, whereas E.

Antigens and Phage Susceptibility Cell wall Oflagellar Hand capsular K antigens are used to aid in classifying certain organisms at the species level, to classifications of bacteria strains of medically important species for epidemiologic purposes, or to identify serotypes of public health importance.

Serotyping is also sometimes used to distinguish strains classifications of bacteria exceptional virulence or public health importance, for example with V.