Introduction Clostridium perfringens are gram-positive rod-shaped bacteria that cause frequent foodborne diarrheal disease reported every year. It is one of the most commonly occurring foodborne diseases mainly in industrialized nations. Clostridium perfringens is ubiquitous in the environment and is pathogenic … Read more
Structure of Norwalk Virus (Norovirus) The virus is non-enveloped, round, 27-nm particles with a ‘ragged’ outer edge but lacking a definite surface structure. It has a buoyant density of 1.33–1.41 g/cm3, an inability to propagate in vitro. Characteristically, Norwalk virus possesses … Read more
They are also known as Group A Streptococcus (GAS) or Group A (beta-hemolytic) Streptococcus (GABHS). Habitat of Streptococcus pyogenes They are found in the throat and skin of humans. They are commensals of the upper respiratory tract. The Carrier rate of S. … Read more
What is Listeriosis? Listeriosis or listeria infection is the major cause of foodborne illness by a causative agent Listeria monocytogenes. After the consumption of contaminated food caused by the bacteria, mild fever or illness may appear but a systemic (invasive) … Read more
Protein Synthesis Definition Protein Synthesis is a process of synthesizing proteins in a chain of amino acids known as polypeptides. It is the second part of the central dogma in genetics. It takes place in the ribosomes found in the … Read more
Homeostasis Definition Homeostasis is the ability of living systems to maintain a steady and uniform internal environment to allow the normal functioning of the systems. It is the tendency to achieve equilibrium against various natural and environmental factors. Homeostasis results … Read more
What is the Bile Esculin Test? The bile-esculin test is a biochemical test performed to differentiate Enterococci and group D Streptococci from non-group D viridans group Streptococci on the basis of their ability to hydrolyze esculin. Many organisms are capable … Read more
What is Dengue and Dengue Virus? Dengue is a mosquito-borne infection caused by a single-stranded RNA virus belonging to the Flaviviridae family known as the Dengue virus (DENV). It is transmitted by different species of female Aedes mosquito, primarily Aedes … Read more
Habitat of Acinetobacter baumannii The first Acinetobacter found in soil was discovered in 1911 by M.W. Beijerinck. It is associated with the aquatics environment. It has been recovered from soil, water, animals, and humans. Found in the respiratory and oropharynx secretions … Read more
Batch Culture Definition In batch culture, all the medium components are placed in the reactor at the start of cultivation except for atmospheric gases, acid or base for pH control, and antifoaming agents. There is a continuous change in the … Read more
Introduction Fish is one of the most consumed seafood and it is a highly perishable food product. Fish and fish products are widely consumed as it is a good nutrition source due to their high protein content, unsaturated fatty acids, … Read more
Protein Synthesis involves translating the sequence of a messenger RNA (mRNA) molecule to a sequence of amino acids during protein synthesis. It is the process in which ribosomes in the cytoplasm or ER synthesize proteins after the process of transcription of DNA to RNA. The Ribosomes Ribosomes exist normally as … Read more
Continuous Culture Definition Continuous culture is a continuous process where nutrients are continually added to the bioreactor and the culture broth (containing cells and metabolites) is removed at the same time. The volume of the culture broth is constant due … Read more
Fed-batch culture Definition In simple words, fed-batch culture is a modification to batch fermentation. In fed-batch cultivation, nutrients are added aseptically; it is a semi-open system, and the volume of liquid culture in the bioreactor increases as the culture is … Read more
Batch Culture Definition In batch fermentation, all the medium components are placed in the reactor at the start of cultivation except for atmospheric gases, acid or base for pH control, and antifoaming agents. There is a continuous change in the nutrient concentrations over time, and the system … Read more
Bioreactor Definition A bioreactor is a type of fermentation vessel that is used for the production of various chemicals and biological reactions. It is a closed container with adequate arrangement for aeration, agitation, temperature and pH control, and drain or … Read more
Introduction Fermentation is one of the ancient food processing technologies. Fermentation is defined as a process in which chemical changes occur in an organic substrate through the action of enzymes produced by microorganisms. For example, yeast enzymes convert sugars and … Read more
What is Penicillin? Alexander Fleming in September 1928 accidentally discovered Penicillin. He found that the fungus, Penicillium notatum prevented the growth of bacteria, Staphylococcus spp.. Later Clutterbuck and his colleagues in 1932 studied the nature of Penicillin and found it … Read more
Pathogenesis of Rickettsia rickettsii Human gets infected when infected adult tick inoculates Rickettsia rickettsii into the skin while taking a blood meal. It usually takes 6 hours of attachment and feeding before rickettsiae are transmitted to the host. Infection can also … Read more
Lymphocytes are the cells that specifically recognize and respond to foreign antigens and are mediators of humoral and cellular immunity. Lymphocytes, the unique cells of adaptive immunity, are the only cells in the body that express clonally distributed antigen receptors, … Read more
Macrophages The mononuclear phagocytic system consists of monocytes circulating in the blood and macrophages in the tissues. The monocyte is considered a leukocyte in transit through the blood, which becomes a macrophage when fixed in a tissue. Monocytes and macrophages … Read more