Transmission electron microscope utilise an electron beam which passes through and interacts with an ultra-thin sample to produce an image, which is then magnified and focused on an imaging device (a fluorescent screen), on a...
Author - Santhakumar Raja
Scanning electron microscopy utilises electron beam for producing high-resolution images of sample surfaces. It forms 3-D view of the sample. It also gives the surface topography of the sample with sufficient clarity and depth of...
The term growth in microbiology indicates the magnitude of total population. Microbial growth measurement is essential for: Determining the growth and reproduction rate, Determining the suitability of water, milk, and food for...
In this method, an individual desired cell is picked up from the mixed culture and allowed to grow. For this purpose following two methods are used: Capillary Pipette Method : In this method (figure), a few small drops of a...
Culture is a procedure during which microorganisms are cultivated in a medium; if a culture has the population of a single type of microorganism; it is known as a pure culture. Usually, isolation and growth of pure cultures of...
To cultivate a specific microbe, following methods are used : Methods of Culturing Aerobic Bacteria : An atmosphere having oxygen in ample amount facilitates the growth of aerobic or facultative bacteria. For this, a large...
On the basis of morphology, bacteria are classified into the following three forms: Spherical : These are coccus bacteria which are spherical in shape. The word coccus originated from the Greek word kokkos meaning berry. They are...
Structure enclosed by the cell membrane is known as cytoplasm, which is aqueous, semitransparent, elastic, and thick. Cytoplasm consists of 80% water and remaining 20% include proteins (enzymes), carbohydrates, lipids...
Immediately below the cell wall, plasma membrane is present which is also known as cytoplasmic membrane, inner membrane, or cell membrane. In prokaryotes, plasma membrane thickness is about 7.5nm (0.0075μm). Phospholipids :...
Gram-Positive Bacterial Cell Wall Cell wall of gram-positive bacteria (figure), is approximately 80nm thick having several layers of peptidoglycan. Peptidoglycan : It contributes to 50−90% of the dry weight of the cell wall...
