Do Eubacteria Have A Cell Wall: 7 Interesting FACTS


In this article, we get know about ‘Do Eubacteria have a cell wall’ and their Cell Wall structure, functions and composition along with 7 interesting facts

A genus of Gram-positive bacteria called Eubacterium belongs to the Eubacteriaceae family. An important characteristic of these bacteria is their thick cell wall. They could either have motility or not. They possess a flagellum if they are moving. A flagellum’s basal body, filament, and hook make up a typical structure. The organ that aids eubacteria in movement is the long filament.

Example: Types of Eubacteria

Bacilli, Cocci, and Spirilla are the 3 types of bacteria which are primarily categorised according to the shapes they take. The classification of bacteria is frequently done using their forms. Following division, bacteria join together to form a variety of structures and shapes, including filaments, clusters, and tightly wrapped coils. Let’s get into the further detail about the three shapes.

1. Bacilli: These bacteria have a rod-like form.

2. Cocci: By definition, they are spherical.

3. Spirilla: In nature, they frequently have spiral or wave-shaped structures.

do eubacteria have a cell wall
Types of Eubacteria from Wikipedia

Do all eubacteria have cell walls

Prokaryotic microorganisms known as eubacteria are made up of a single cell without a nucleus that houses a single circular chromosome of DNA. Bacteria having cell walls made of peptidoglycan are known as prokaryotic Eubacteria. Cell walls are not present in all bacteria, though. But the cell membrane is present in all eubacteria. Glycerol and fatty acids are joined by an ester bond to form the basic components of bacterial cell membranes.

Example:  Eubacteria are significant in the fields of commercial, agriculture, and medicine and can be either gram-negative or gram-positive. E. coli, Lactobacilli, and Azospirillum are some of them.

do eubacteria have a cell wall
Eubacteria: (E. coli) Scanning electron micrograph from Wikipedia.

Why do eubacteria have cell walls?

A cell wall encloses eubacteria. The peptidoglycan, a polymer that comprises both amino acid and sugar chains, chains that are cross-linked form the wall. Because of the network structure, the wall has the stability required to maintain its shape and size despite changing chemical and osmotic variations outside the cell.

Example:

  • Outside of the cell wall, some bacteria have an extra layer. Lipopolysaccharide (LPS), a compound of lipids and sugars, is used to create this layer. The effects of having this outer layer are numerous.
  • The existence of this LPS layer distinguishes Gram-positive bacteria from Gram-negative bacteria, which lack an outer LPS layer and do not retain the stain.

Eubacteria cell wall composition

The cell wall surrounds the plasma membrane. This relatively rigid layer provides structural integrity to the cell. Peptidoglycan makes up eubacterial cell walls. N-acetyl glucosamine, N-acetyl muramic acid, and numerous amino acids, including as D-glutamic acid, D-alanine, and meso-diaminopimelic acid, are combined to form the polymer known as peptididoglycan.

Example:

  • Peptidoglycan chains are crosslinked via peptides. This cross-linking results in a dense, structurally sound cell wall that protects bacteria from osmotic lysis and maintains cell shape. Peptidoglycan thickness varies between bacteria.
  • Gram-positive and Gram-negative bacteria can be divided into two categories using the Gram stain, a differential staining technique. Gram-positive bacteria exhibit a purple stain because their peptidoglycan coating is thicker. The peptidoglycan layer in Gram-positive bacteria can be ranged between 20 and 80 nm thick.
  • Lipopolysaccharide (LPS): Gram-negative bacteria have an extra outer layer covering a thinner (2 to 7 nm) peptidoglycan layer. Gram-negative bacteria have a pink colour in the Gram stain because their peptidoglycan coating is thinner. Lipopolysaccharide makes up the Gram-negative cells’ outer membrane (LPS).
  • Lipid A, a core polysaccharide, and the O side chain make up the three components of the massive, intricate molecule known as LPS. LPS serves as an additional protective barrier by inhibiting the entry of potentially toxic substances into the cell. LPS is also an endotoxin.
  • Lipid A, a component of LPS, triggers an immune response and is responsible for some symptoms of a Gram-negative bacterial infection.

Eubacteria cell wall diagram

do eubacteria have a cell wall
Gram-negative cell envelope structure from wikipedia

Example: Many gram-negative bacteria have an intricate lipopolysaccharide in their outer leaflet of their outer membrane, and this lipopolysaccharide’s lipid component acts as an endotoxin. It is connected to the peptidoglycan of the cell in some bacteria, such as E. coli, by Braun’s lipoprotein. In comparison to the inner cytoplasmic cell membrane, it has a distinct composition.

Characteristics of Eubacteria 

  • The “true bacterium” is another name for Eubacteria.
  • In Eubacteria, peptidoglycans create the rigid cell wall.
  • Flagella are a means of propulsion.
  • A few bacteria feature pili, which are tiny projections on the cell surface that aid or facilitate sexual reproduction in the bacteria. Additionally, pili promotes or facilitates viruses’ adhesion to their hosts.
  • Depending on the type of cell wall and staining they exhibit, they are categorised as either gram-positive or gram-negative. Where gram-positive bacteria are good for human health and gram-negative, bacteria are toxic to humans.
  • Rhizobium and Clostridium are two examples of eubacteria.

Are eubacteria cell walls rigid?

In order to be classified as eubacteria, or “real bacteria,” an organism must have a hard cell wall and, if it is mobile, a flagellum. Cyanobacteria and heterotrophic bacteria are the two subgroups of eubacteria.

Example: The cyanobacteria, commonly known as blue-green algae, are photosynthetic autotrophs with chlorophyll that resembles that of green plants. The majority of microorganisms in nature are heterotrophic. Most of them are significant decomposers.

Is eubacteria cell wall permeable?

The majority of eubacteria have a cellular wall that is constructed of cross-linked chains of peptidoglycans. The bacteria acquires the strength it requires in this way to maintain its size and shape in the face of varying environmental conditions. Smaller molecules can permeate past the cell wall on their own, whereas larger molecules and ions need carrier proteins and channel proteins to pass through the membrane.

Do eubacteria cells have a chloroplast?

They lack internal organelles like chloroplasts and mitochondria. Deoxyribonucleic acid (DNA) in bacteria is loosely grouped into a nucleoid, similar to how it is in archaea, and is not encased by a nuclear membrane, as it is in eukaryotes.

Example: Both halobacteria and eubacteria, including the nonphotosynthetic eubacteria, include crucial elements of the photosynthetic system, such as carotenoids, which suggests that photosynthesis may be a primitive characteristic of both groups.

Conclusion

In the above article, we studied about Eubacterial cell wall structure and characteristics

Ganeshprasad DN

Hi....I am Ganeshprasad DN, completed my Ph.D. in Biochemistry from Mangalore University, I intend to use my knowledge and technical skills to further pursue research in my chosen field. LinkedIn : linkedin.com/in/d-n-ganeshprasad-157b8a107

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