Tiêu đề Med-RM_Bot_SP-3_Ch-17_Microbes in Human Welfare.pdf ✅

Chapter Contents Aakash Educational Services Limited - Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005 Ph. 011-47623456 Microbes in Household products Microbes in Industrial products Microbes in Sewage Treatment Microbes in Production of Biogas Biocontrol Agents Microbes as a Biofertilisers Chapter 17 Microbes in Human Welfare Microbes belong to diverse group of organisms like bacteria, fungi, protozoa and microscopic plants. Some of the microbes are shown below. Bacteria: (a) Rod-shaped, magnified 1500X; (b) Spherical shaped, magnified 1500X; (c) A rod-shaped bacterium showing flagella, magnified 50,000X (a) (b) (c) Rod shaped bacterium Flagella (a) (b) Head Collar Tail Plate Pins Prongs
204 Microbes in Human Welfare NEET Aakash Educational Services Limited - Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005 Ph. 011-47623456 Compact Rod-shaped viruses (c) Fig.: Viruses : (a) A bacteriophage; (b) Adenovirus which causes respiratory infections; (c) Rod-shaped Tobacco Mosaic Virus (TMV). Magnified about 1,00,000 – 1,50,000X Microbes like bacteria and many fungi can be grown on nutritive media to form colonies. (a) (b) Fungal colony Fig.: (a) Colonies of bacteria growing in a petri dish; (b) Fungal colony growing in a petri dish While microbes are causal agents of most of the infectious diseases, they are also useful to humans in many important processes at home, industries, agriculture and sewage treatment. MICROBES IN HOUSEHOLD PRODUCTS (a) Curd : Micro-organisms such as Lactobacillus and others commonly called lactic acid bacteria [LAB] grow in milk and convert it into curd. 1. During growth, the LAB produce acids that coagulate and partially digest the milk proteins. 2. The starter or inoculum contains millions of LAB, which at suitable temperatures multiply. 3. Curd is more nutritious than milk as it contains a number of vitamins especially B12. 4. In our stomach LAB play very beneficial role in checking disease causing microbes. (b) Cheese : It is one of the oldest food items in which microbes were used. It is partially degraded concentrate of milk fat and casein (milk protein). Different varieties of cheese are known by their characteristic texture, flavour and taste, the specificity is determined by the microbes used for its ripening Examples: 1. Large holed Swiss cheese - Ripened by bacterium Propionibacterium sharmanii. 2. Roquefort cheese - Ripened by Penicillium roquefortii. 3. Camembert cheese - Penicillium camembertii. (c) Bread : Bread is prepared from dough, which is fermented using Baker’s yeast (Saccharomyces cerevisiae). Puffed-up appearance of dough is due to production of CO2 during fermentation. CO2 gas along with ethyl alcohol evaporate during baking, making bread porous and soft. (d) Dosa and Idli: The fermented preparation of rice and black gram, prepared by using bacteria. e.g, Leuconostoc and Streptococcus
NEET Microbes in Human Welfare 205 Aakash Educational Services Limited - Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005 Ph. 011-47623456 (e) Toddy : It is traditional drink of some parts of South India and is made by fermenting sap from palm known as Caryota urens. Toddy left for few hours undergoes fermentation due to presence of naturally occurring yeast. MICROBES IN INDUSTRIAL PRODUCTS Production of beverages and antibiotics on an industrial scale, is done by growing microbes in very large vessels called fermentors. Fig.: Fermentors (a) Fermented Beverages (i) Yeast species used in alcoholic fermentation are : Saccharomyces cerevisiae commonly called Brewer’s yeast, S. ellipsoidens – Wine yeast, S. pireformis – Ginger beer/Ale yeast. (ii) Depending on the type of the raw material used for fermentation and the type of processing (with or without distillation) different types of alcoholic drinks are obtained. (iii) Wine and beer are produced without distillation (Low alcohol concentration). (iv) Whisky, brandy and rum are produced by distillation of fermented broth (high alcohol concentration). Table : Alcoholic beverages with substrates and their concentration Alcohol Concentration of alcohol Substrate used 1. Beer 2. Wine 3. Whisky 4. Brandy 5. Rum 6. Gin 7. Vodka Barley malt Fruit juices Fermented cereals Fruit juices Molasses Rye malt Potato 3-6% 9-12% 50% 60-70% 40% 40% 60-80% Fig.: Fermentation Plant