Title MICROBES IN HUMAN WELFARE.pdf ✅

MICROBES IN HOUSEHOLD PRODUCTS DAIRY PRODUCT 1) CURD Micro-organisms such as Lactobacillus and others commonly called lactic acid bacteria (LAB) grow in milk and convert it to curd. During growth, the LAB produce acids that coagulate and partially digest the milk proteins. A small amount of curd added to the fresh milk as inoculum or starter contain millions of LAB, which at suitable temperatures multiply, thus converting milk to curd, which also improves its nutritional quality by increasing vitamin B . In our stomach too, the LAB play very beneficial role in checking disease causing microbes. 2) YOGHURT For production of yoghurt pasteurized milk is inoculated with a mixture of Streptococcus thermophilus and Lactobacillus bulgaricus and its lactose is fermented by keeping it at 40°C. The peculiar or char- acteristic taste and flavour of yoghurt is due to presence of lactic acid and acetaldehyde. 3) CHEESE Cheese, is one of the oldest food items in which microbes were used. Different varieties of cheese are known by their characteristic textur flavour and taste, the specificity coming from the microbes used. Cheese is mainly two different types. I. Unripened cheese - Ripened from out side-soft II. Ripened cheese - It is hard and ripened externally as well as internally. Manufacturing cheese involve following steps. i) Milk is inoculated with starter culture of bacteria - Streptococcus lactis or S.cremoris and warmed at 38°C. If higher temperature [50°C or more] then S.thermophilus combined with Lactobaccilus lactis, L.bulgaricus or L.helveticus. ii) When a certain acidity reached in milk by the activity of species of bacteria then rennet enzyme is added. Curdling of milk occurs within half an hour to one hour. iii) The curd is removed and liquid separates out which is called whey [contain 93% water and 5% Lactose]. Lactose of whey is used for the manufacture of Lactic acid - First fermented acid. If the cheese is used at this stage is called cottage cheese (unripened stage). iv) The salts mixed with cottage cheese and put into the frames and pressed so as to allow removal of whey. Salts hastens the removal moisture and prevent the growth of undesriable microbes. The frames
are removed as soon as the cheese has set sufficiently to maintin its shape. The ripening period varies from 1-16 months but which is very tasty and nutritious. This is hard and ripened cheese contains about 20-30% fats, 20-35% proteins and small amount of minerals and vita- mins. [Cheese which prepared at homes with the help of lemon juice is called Raw cheese] Nearly 400 varieties of cheese available which can be classified into following type -? Type of Cheese Micro Organisms used for ripening 1. Soft Camembert cheese Penicillium camemberti 2. Semi-hard Roquefort cheese Penicillium roqueforti 3. Hard Swiss cheese Propionibacterium sharmanii The large holes in 'Swiss cheese' are due to production of a large amount of C02 by a bacterium named Propionibacterium sharmanii. OTHER PRODUCT The dough , which is used for making foods such as dosa and idli is also fermented by bacteria. The puffed-up appearance of dough is due to the production of C02 gas. Similarly the dough, which is used for making bread, is fermented using baker's yeast (Saccharomyces cerevisiae). A number of traditional drinks (e.g. 'Toddy' prepared from sap of palms) and foods are also made by fermentation by the microbes. Microbes are also used to ferment fish, soyabean and bamboo shoots to make foods. MICROBES IN INDUSTRIAL PRODUCTS 1. ALCOHOLIC (Fermanted) BEVERAGE Microbes especially yeasts have been used from time immemorial for the production of beverages like wine, beer, whisky, brandy or rum. For this purpose the same yeast Saccharomyces cerevisiae used for bread-making and commonly called brewer's yeast, is used for fermenting malted cereals and fruit juices, to produce ethanol. 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. Wine and beer are produced without distillation whereas whisky, brandy and rum are produced by distilla- tion of the fermented broth. Some other common products of yeast fermentation are - [i] Beer - It is produced from Hordeum Vulgare[Barely] malt and alcohol content is 3-6% [ii] Wine - Produced from grapes, alcohol content is 10-20%. [iii] Brandy - Produced by distilation of wine and alcohol content is 60-70% [iv] Gin - Produced from European Rye-Scale cereal, alcohol content is 40%. [v] Rum - Produced from Molasses of Sugarcane and alcohol contents is 40%
Fermentor Fermentation plant ANTIBIOTICS The term was coined by Selman Waksman (1942) Antibiotics produced by microbes are regarded as one of the most significant discoveries of the twen- tieth century and have greatly contributed towards the welfare of the human society. Anti is a Greek word that means 'against', and bio means 'life', together they mean "against life' (in the context of disease causing organisms); whereas with reference to human beings, they are 'pro life' and not against. Antibiotics are chemical substances, which are produced by some microbes and can kill or retard the growth of other (disease-causing) microbes. You are familiar with the commonly used antibiotic Penicillin. Do you know that Penicillin was the first antibiotic to be discovered and it was a chance discovery? Alexander Fleming while working on Staphylococci bacteria, once observed a mould growing in one of his unwashed culture plates around which Staphylococci could not grow. He found out that it was due to a chemical produced by the mould and he named it Penicillin after the mould Penicillium notatum. However, its full potential as an effective antibiotic was established much later by Ernest Chain and Howard Florey. This antibiotic was extensively used to treat American soldiers wounded in World War II. Fleming, Chain and Florey were awarded the Nobel Prize in 1945, for this discovery. After Penicillin, other antibiotics were also purified from other microbes. Antibiotics have greatly improved our capacity to treat deadly diseases such as plague, whooping cough (kali khansi), diphthe- ria [gal ghotu) and leprosy (kusht rog), which used to kill millions all over the globe. Today, we cannot imagine a world without antibiotics. Main sources of Antibiotic :- The main sources of Antibiotics production are three types - i) Eubacterials - Most of this type of antibiotic is obtaind from Bacillus sps 70%. Bacillus subtilis produced more than 60 Antibiotics and from Pseudomonas species 30%. ii) Actinomycetales [Ramified ] - Streptomyces, Micromonospora and streptosporangium. From single species Streptomyces griseus more than 40 antibiotics have been obtained. iii) Fungi - Penicillium.
ORGANIC ACIDS Some organic acids are manufactured by employing fermentation activities of Fungi and others of Bacteria. For example 1. Citric Acid : It is obtained by the aerobic fermentation of sucrose by the fungus Aspergillus niger. This acid is used in medicine, flavouring extracts, food and candies; the manufacture of ink, dyeing. It is also produced by yeast. 2.Acetic acid or Vinegar : Vinegar production is a two step fermentation process A. First step : Alcoholic fermentation of a carbohydrate in to alcohol by yeast. B. Second step: Aerobic oxidation of alcohol into acetic acid by the Bacterium Acetobactoer aceti. Vinegar is a french word, meaning - sour wine, and was known to man thousands of years ago. The Vinegar is the product of microbial fermentation, was recognised by Kutzing in 1837. In 1868 Pasteur discovered it to be a result of Biological Activity. Vinegar is used in various ways in homes. It is used as a condiment and for preserving pickles, canned vegetables and fruits. Medicinally, it has an important role in promoting digestion and in overcoming constipation. 3. Lactic Acid : Produced by fermentation of com starch, Molasses potatoes and whey by bacterium Lactobacillus bulgaris and Streptococcus lactis. 4. Butyric acid - Obtained by bacterium clostidium butylicum. 4. ENZYMES i) Rennet - Used in Manufacturing "Cheese" Old days cheese had been prepared either using the layer of stomach of Goat or Sheep or the sap of Fig tree, containing special enzyme-Ficin. In 1874 a Danish Chemist - Christian Hansen extracted pure rennet enzyme from Calf's stomach for industrial production of cheese. First of all diastase enzyme was identify by payen and persoz (1933) ii) Proteases - This enzyme obtained from Aspergillus orizae and Bacillus subtilis, Bacillus licheniformis and utilized from the formation of detergents in detergent industry (For removing proteinous strains on clothes]. The bottlejuices are clarified by the use of pectinases and protease. iii) Amylases - It works on starch and used in Beer, Bread and Textiles industries. iv) Amylase, Gluco amylase and Gluco isomerase - By the action of all these enzymes corn (maize) starch transformed into fructose com syrup. This syrup is more seeter than sucrose and used in bever- age industry to flavour soft drinks and in baking industry to sweeten biscuits and cakes. v) Streptokinase/Tissue Plasminogen Activator [TPA] - This enzyme utilized in medicinal field. Streptokinase produced by the bacterium Streptococcus and modified by genetic engineering is used as a clot buster for removing clots from the blood vessels of patients who have undergone myocardial infraction leading to heart attack. 5. BIOACTIVE MOLECULE i) Cyclosporin A, that is used as an immunosuppressive agent in organ-transplant patients, is pro- duced by the fungus Trichoderma polysporum. ii) Statins produced by the yeast Monascus purpureus have been commercialised as blood -cholesterol lowering agents. It acts by competitively inhibiting the enzyme responsible for synthesis of cholesterol. MICROBES AS BIOCONTROL AGENTS