Bacteria | Bacteria Characteristics | Bacteria Shapes | Types of Bacteria

 

Topics to be covers

Bacteria,

Bacteria Characteristics,

Bacteria Shapes and 

Types of Bacteria.

Bacteria

Bacteria are single celled prokaryotic microorganisms that lack a proper nucleus as well as a few organelles.

Bacteria Characteristics

Bacteria are organisms with only one cell. They lack organelles like chloroplasts and mitochondria, as well as the true nucleus that eukaryotic cells possess. Instead, their DNA, which is a continuous and circular double strand, is housed in a nucleoid. The nucleoid is a non-nuclear membrane-free area with an irregular shape. Bacteria possess a peptidoglycan cell membrane and cell wall. The cellular envelope is made up of the cell membrane and cell wall. To live, many bacteria require a cell wall.

Binary fission, or the breaking of a bacterial cell once it reaches a specific size, is used for reproduction. Bacteria reproduce asexually, therefore binary fission produces two daughter cells with the identical DNA as the parent cell. However, through a process known as horizontal gene transfer, certain bacteria may share genetic material with one another. This approach uses two bacteria that already exist; it is not a mechanism of transfer from parent to kid.

Bacteria Shapes

Bacteria appear in a diverse range of shapes and sizes. Coccus, spiral, and bacillus are the three primary forms of bacteria.

Coccus

Cocci are spherical or ovoid bacteria with a spherical or ovoid form. Even when independent cells are created during binary fission, some cocci stay connected. Diplococci are cocci in pairs, and staphylococci are clusters of many cocci. Tetrads are four cocci arranged in a square, whereas sarcinae are eight cocci arranged in a cube.

e.g., Staphylococcus aureus, Streptococcus pyogenes.

 

Spirillum

Spiral bacteria are spiral-shaped, as the name implies. Spirillums are a type of spiral that is thick and strong. Spirochetes are very thin and flexible spirals. Vibrios are comma-shaped rods that have a little twist to them.

e.g., Spirillum, Vibrio, Spirochete species.

Bacillus 

Bacilli are bacteria that have a rod-like form. Bacilli, like cocci, can be solitary or grouped together. Streptobacilli are bacilli chains, whereas diplobacilli are two bacilli stacked on top of each other. Other bacterial morphologies include filamentous (long and thin), square, star-shaped, and stalked bacteria.

Types of Bacteria

Because of the cell wall, Gram staining is also possible. Gram staining requires the utilization of crystal violet dye, iodine, and the counterstain safranin to stain bacteria. Gram-positive bacteria display the stain and look violet in hue under a microscope, whereas gram-negative bacteria show just the counterstain and appear red. Gram-positive bacteria have thick cell walls that capture the crystal violet-iodine mixture, giving them their violet color. The violet-iodine combination cannot be held by Gram-negative bacteria's thin cell walls, whereas safranin can. As a result, Gram-negative bacteria appear red when stained using Gram staining. Gram staining may be used to identify bacteria in general or detect the presence of specific bacteria, but it cannot be used to identify bacteria in depth, such as at the species level. Listeria, Streptococcus, and Bacillus are examples of Gram-positive bacteria, whereas Proteobacteria, and cyanobacteria are examples of Gram-negative bacteria.