Transpeptidation reaction is the chemical reaction that forms the peptide cross-links or bonds during the synthesis of peptidoglycan (murein) in a bacterial cell wall. Peptidoglycan or murein is a polysaccharide molecule that consists mainly of alternating repeats of N-acetylglusamine (NAG) and N-acetylmuramic acid (NAM). Murein is a bacterial cell wall polymer that contains short peptide […]
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Microbial Physiology & Metabolism
Cell wall is a layer that is present outside the plasma or cytoplasmic membrane of a prokaryotic cell. It is present in both Gram-positive bacteria (Figure 1) and Gram-negative bacteria (2) even though some bacteria (e.g. Mycoplasmas) are wall-less i.e. they do not possess cell wall. Wall-less bacteria do not react to the Gram stain
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Microbial Physiology & Metabolism
Eukaryotic cells are organisms or cells that have a membrane-bound nucleus. They are distinct group of organisms that have a unit membrane-enclosed nucleus and other organelles such as the mitochondria that are membrane-bound . They are different from prokaryotic cells which lack membrane-bound nucleus. The term eukaryote is derived from the Greek word eu which
Based on their effects on the structural integrity of the DNA molecule, mutations can be classified as substitution, insertion, deletion, inversion, reciprocal translocation and chromosomal rearrangements. SUBSTITUTION (BASE-PAIR SUBSTITUTION) Substitution literally means the act of replacing one thing with another. When base substitution as a type of mutation occurs during DNA replication, a single base
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Biotechnology
The term mutation is derived from the Latin word “mutare” – which means “to change”. Thus, mutation is simply defined as the change in genetic makeup (genotype) of an organism which results in the transformation of the phenotype of the organism. Mutation is an inheritable change in the base sequence of the genome of an
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Biotechnology
Microorganisms including bacteria, fungi, algae and viruses are important tools used for a wide variety of pharmaceutical and/or biotechnological processes including but not limited to drug and vaccine production, single cell protein production, production of probiotics and other therapeutic, cosmetic or pharmaceutical products. For effective and sustainable production of useful microbial by-products, microorganisms can be
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Biotechnology
The phrase liposome is derived from two Greek words: Lipos which means “fat” and Soma which means “body”. Liposomes (also known as closed bilayer phospholipid systems) are artificial spherical vesicles that possess several or at least one lipid bilayer for the incorporation of an active agent such as a drug. They are often used as
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Biotechnology
Pathogenic bacteria enter the human body in various ways and through various medium or routes. Some of the portal of entry of infectious agents into our body including bacteria, protozoa, viruses and fungi are as follows: THE SKIN The human skin is usually the first physical barrier that prevents the entry of pathogenic microorganisms into
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Epidemiology
Hazard analysis critical control point (HACCP) is an internationally recognized food safety system that is employed in the production line of food and food products in food processing industries to ensure food safety, food hygiene and good food quality. It is a quality assurance technique or system that is used especially in food processing and
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Pharmaceutical Microbiology, Food Microbiology
Indicator organisms are microorganisms that signify the possible contamination of food or food products as well as other materials or environment. They are organisms whose presence in a material or environment serves to indicate the condition or quality of the material or environment. To meet the local and internationally established microbiological criteria for safe and
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Pharmaceutical Microbiology, Environmental & Soil Microbiology, Food Microbiology