Fermentation systems

Fermentation systems

Fermentation systems Microbiologists use the term fermentation in total two different contexts. First, in metabolism, fermentation refers to energy-generating processes wherever organic compounds act as both electron donor and acceptor.  Second, within the context of industrial microbiology, the term also refers to the growth of huge quantities of cells under aerobic or anaerobic conditions, within …

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Wort Preparation


WORT PREPARATION The objectives of wort preparation are to form, and extract into solution, fermentable sugars, amino acids, vitamins, etc., from malt and other solid ingredients. Malt normally provides most of the potential fermentable materials and sufficient enzymes to generate a well balanced fermentation medium. Typically, British beer is prepared from 75% malt, and 25% …


Malt and malting


MALT AND MALTING Malting involves the controlled partial germination of barley grain. This modifies the hard vitreous grain into a friable (easily crushed) form containing a lot of readily degradable starch and generates hydrolytic enzymes, particularly amylases, b-glucanases and proteases. Barley grains have approximately 65% starch, located within the endosperm region. Endosperm cells are filled with starch granules embedded in …


beer process

Beer brewing

Beer brewing The name beer is given to non-distilled alcoholic beverages are made from partially germinated cereal grains, known as malt. They include ales, lagers and stouts, which normally contain 3–8% (v/v) ethanol.  The other main ingredients are hops (giving beer a characteristic aroma and flavour), yeast and water. The brewing process is mainly divided into four main stages:- Malting Mashing and …

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An infusion mash tun

Types of Mashing systems

Types of Mashing systems Three main mashing systems are operated:- Infusion mashing Decoction mashing Temperature programmed mashing Infusion mashing: Infusion mashing is the classic British methodology for ales and stouts, using well-modified malt and relatively simple instrumentation.   Solid mash ingredients are mixed with hot brewing liquor to gain a mash temperature of 62–65°C. Mixing is performed during passage to an insulated …

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Transposons Transposons are a kind of mobile DNA  (deoxyribonucleic acid) of 2000–20,000 bp. They can transfer DNA (deoxyribonucleic acid) from one site of the bacterial chromosome to another site or to a plasmid. The theroy of transposons or jumping genes was first given by Barbara McClintock, a geneticist working in the field of maize genetics.  The mode …

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Normal Microbiota of the Urinary and Reproductive Systems

Normal Microbiota of the Urinary and Reproductive Systems

Normal Microbiota of the Urinary and Reproductive Systems Normal urine is sterile, However it should become contaminated with microbiota of the skin near the end of its passage through the urethra. Therefore, urine collected directly from the urinary bladder has fewer microorganism contaminants than voided urine. The predominant bacteria in the vagina are the lactobacilli. These bacteria produce …

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The lac operon is inducible

lac operon

lac operon An example that has been studied in great depth concerns the enzyme β-galactosidase, used by E. coli to convert the disaccharide lactose into its sugars constituent: Lactose −−−−−−−−→ Glucose + Galactoseβ-galactosidase β-galactosidase has been more studied as part of the lac operon of E. coli. This is made up of three structural genes designated Z, Y and A, …

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