Spores, Antibiotics and Bacteria

Spores and Unfavorable Conditions

• Bacterial cells form spores to endure adverse conditions like vegetation drying.
• The cell's contents condense into a spherical mass encased in a thick, rigid wall, creating a spore inside the original cell.
• The spore breaks free when the cell wall ruptures and usually acts as a dormant phase to withstand harsh conditions.
• Spores possess tolerance to extreme dryness, high temperatures (such as boiling water), freezing temperatures, and poisonous chemicals.
• Spores disseminate over great distances via wind, water, or physical contact.
• They germinate in favorable conditions, activating dormant protoplasm that emerges from the ruptured wall as a new bacterium.

Bacteria's Role in Medicine

• Bacteria contribute to the production of antibiotics, serums, and vaccines.

Antibiotics

• Antibiotics, produced by microorganisms, can inhibit the growth of or eliminate disease-causing bacteria and fungi.
• Many antibiotics, including streptomycin, chloromycetin, tetracycline, and penicillin, are widely used in treating infections.
• Penicillin, the first antibiotic, was derived from the fungus Penicillium chrysogenum.
• Alexander Fleming found that Penicillium chrysogenum suppressed bacterial growth.
• Streptomycin was later discovered by Selman Waksman and originates from Streptomyces griseus.

Ideal Antibiotic Criteria

• A good antibiotic should target a broad range of disease-causing microorganisms.
• It shouldn't have undesirable side effects or harm the host's normal bacteria.

Additional Uses of Antibiotics

• Used as preservatives for fresh meat and fish and in treating animal feed, and controlling plant pathogens.

Serums

• Serum is the blood plasma without fibrinogen, containing antibodies/antitoxins.
• Toxins are poisonous proteins released by pathogenic bacteria either during their growth or upon their decomposition.
• Antitoxins neutralize toxins produced by invading germs.
• Serums with antitoxins prevent bacterial invasions.
• Serum preparation involves injecting a healthy animal with a small dose of bacterial toxin, triggering antitoxin production.
• After repeated toxin injections, the animal’s blood is collected and chilled, yielding a straw-colored liquid serum.
• Snake-bite treatment involves injecting specific antivenin from the blood of immunized horses.

Genetically Modified Bacteria

• Genetic engineering allows insertion of human genes into bacteria like E. coli.
• These bacteria produce gene-dependent products, like the hormone insulin, first produced by genetically engineered E. coli.
• Genetically modified bacteria can produce blood clotting factor VIII for treating Hemophilia A.
• They also produce factor IX for treating Hemophilia B.

Vaccines

• Vaccines contain weakened or dead germs/germ substances,
• Vaccination introduces these into the body to develop resistance to specific diseases.
• Vaccines are available for diseases like cholera, typhoid, measles, and chickenpox.
• Injection stimulates the body to generate antitoxins, providing immunity.
• Common vaccines from bacteria include killed bacteria for TAB vaccine for typhoid
• Common vaccines from bacteria include living weakened bacteria for BCG vaccine for tuberculosis.

Toxoids

• Toxoids are inactivated bacterial toxins that induce antibody production, providing immunity against diseases like diphtheria and tetanus.

Bacteria's Role in Agriculture

• Rhizobium bacteria live in nodules of leguminous plant roots like beans and fix atmospheric nitrogen into soluble nitrates.
• The host plant and subsequent plants use these nitrates.

Free-living Bacteria

• Free-living bacteria, such as Azotobacter and Clostridium, convert atmospheric nitrogen to ammonia, enriching the soil with amino acids and nitrates.

Nitrifying Bacteria

• Plants need nitrogen for synthesizing proteins, but they use nitrates from the soil absorbed through roots.
• Nitrates are replenished through nitrification, where bacteria convert animal wastes and remains into ammonia, then into nitrites (Nitrosomonas) than nitrates (Nitrobacter).

Denitrifying Bacteria

• Denitrifying bacteria like Pseudomonas decompose soil nitrates, releasing nitrogen gas into the atmosphere.

Decay and Putrefaction

• Decay is complete breakdown of organic matter by bacteria without foul smell.
• Putrefaction is incomplete breakdown emitting a foul smell.
• Sewage treatment plants in big cities use sewage bacteria to decompose human waste, producing gas as a byproduct.

Bacteria's Role in Industry

• Fermenting bacteria degrade cellulose in cow dung, releasing methane.
• Biogas plants provide fuel and manure.
• Bacteria synthesize B complex vitamins and vitamin K in intestines, which aids digestion of cellulose in herbivorous animals.
• Bacteria are also used to produce vinegar, process coffee and tobacco.
• Fibers for making rope and linen are obtained by retting.
• Bacteria aid in curing hides and skins.
• Specific bacteria produce different flavors of tea (tea curing).
• Bacteria breakdown perishable parts of skin (hide) for leather tanning.

Spoilage of Food by Bacteria

• Decay (fermentation) spoils cooked food, milk, fruits, and vegetables, causing food poisoning.
• Clostridium in tinned foods leads to botulism; discard distended cans.

Food Preservation

• Food preservation prevents disease-causing germs in food.
• Boiling and heating at high temperatures kills all bacteria except spores, while temperatures at 110°C kill spores.
• The Canning industry uses high temperatures to sterilize before packing
• Salting preserves foods like fish and cheese.
• Curing involves treating food with salt for preservation and prevents bio-degradation.
• Microbes cannot grow without water, and it an effective method to preserve food, like grains, meat, and dried milk.
• Radioactive radiation sterilizes food; ultraviolet light sterilizes air and kills mold spores in bakeries.
• Pasteurization heats milk at 60°C for 30 minutes, killing most bacteria but not sterilizing milk completely.
• Refrigeration inhibits microbial growth, preserving milk, fruits, vegetables, and frozen foods.
• Domestic refrigerators cool at 0-5°C for short-term storage; deep freezing cools at -20°C to -30°C for long-term.
• Strong concentration of sugar and salt prevent spoilage in jams and pickles.
• Preservatives like sodium benzoate are added to canned foods.

Bacterial Diseases of Plants

• Black rot of mustard and cauliflower and bacterial blight of cowpea are plant diseases.

Bacterial Diseases of Animals

• Anthrax (swelling on body and reduced milk yield) and bovine tuberculosis (dry cough, lungs affected) affect animals.

Bacterial Diseases of Humans

• Examples are Whooping cough, cholera, tuberculosis, diphtheria, typhoid, pneumonia and Tetanus.

Bioweapons

• Some countries may prepare germ bombs with Anthrax bacteria to cause widespread death.

Yeast

• Yeast cells have a distinct cell wall, a nucleus, and vacuoles in the cytoplasm.
• Yeasts directly absorb and break apart sugar (glucose) or cane sugar (sucrose).
• Yeasts respire anaerobically without oxygen: C6H12O6 → 2C2H5OH + 2CO2 + 2ATP.

Alcoholic Fermentation

• Yeasts facilitate alcoholic fermentation in the production of ethanol (alcohol).
• Alcohol quality varies based on the fermented material.
• Penicillium species are employed to manufacture flavored cheeses.
• Pencillium chrysogenum is notable for being the source of penicillin.

Harmful Fungi

• Fungi are harmful, and spoil food.
• Penicillium and Aspergillus cause damage to oranges, lemons.
• Some may cause diseases include ringworm.

Antibiotics and Molds

• Penicillin was produced by mold.

Uses of Fungi in Industry

• Used in both Old and traditional practices and rather recent processes.

Wine as an Alcoholic Beverage

• Wine and other alcoholic beverages are products of fermentation.
• Fermentation involves breaking down carbohydrates by microorganisms.

Wine Manufacture

• The source for making wine is grape
• For beer its barley maltose
• The micro-organism employed is yeast (Saccharomyces cerevisiae).
• The biochemical reaction is follows C6H12O6 → 2C2H5OH + 2CO2.
• Grapes are then crushed and the ethanol is produced in the fermentation.
• The concentration is about 12% and kills the yeast cells.
• Spirits like whisky and gin, are distilled for alcoholic content.
• Wine contains variable amount of water, alcohol, carbon dioxide, sugar and a few other substances.
• Wine is absorbed quickly, may be a stimulant or be harmful, and is related to liver cirrhosis.

Baking

• Baking includes flour, fat, salt, water and yeast to create the process of "leavening".
• Yeast produces gas bubbles give the bread a light texture.

Cheese

• Cheese is a valuable food is the byproduct of the fermentation of curd in milk.
• The steps in the process are as follows Curdling, Curd processing, Salting, and Ripening

Mushroom Cultivation

• Vary in shape and size, growing wild in nature.
• Most are poisonous,
• Edible mushrooms are Agaricus bisporous, Volvariella and Pleurotus.
• Mushrooms cultivation is done indoors on agriculture byproducts (compost).
• White button mushroom (Agaricus bisporous) cultivation involves composting, spawning, casing, cropping and harvesting and preservation.