Bacteria and Fungi

Fungi lack chlorophyll, the pigment necessary for photosynthesis, and must therefore obtain nutrients from organic matter as heterotrophs. Other structures like cell walls and nucleoli are present in fungal cells.

Bacteria require specific environmental conditions to thrive, and moisture is a primary factor that promotes their growth and reproduction. High concentrations of salt or oil are often used to inhibit bacterial growth.

Rhizoids are specialized hyphae that grow downward into the substrate to anchor the fungus and absorb nutrients, similar to roots in plants. Mycelia refers to the entire network of hyphae, not just the root-like ones.

The vegetative body of a fungus, consisting of a mass of branching, thread-like hyphae, is called the mycelium. Chitin is the material that makes up the cell wall, not the name of the thallus itself.

The mycelium is the vegetative part of a fungus, consisting of a network of fine white filaments called hyphae. This network forms the cottony mass often seen on bread or in soil. Sporangia are reproductive structures, while rhizoids are root-like structures used for anchorage.

Moulds are fungi that obtain their nutrients by absorbing organic compounds from dead and decaying matter. This specific mode of nutrition is called saprophytic. While moulds are aerobic organisms, that term refers to their respiration rather than their food source.

When microbes are placed in a high-solute (hypertonic) environment, water moves out of their cells via osmosis. This causes the cell membrane to shrink away from the cell wall, a process known as plasmolysis. This dehydration effectively inhibits growth or destroys the bacteria and fungi.

Erythromycin is a macrolide antibiotic effective against the bacteria causing whooping cough and diphtheria. Historically, it was also noted for its activity against certain large pathogens once classified as large viruses, such as Chlamydia. Penicillin is less effective against these specific respiratory infections.

Sodium benzoate is the salt of benzoic acid, and both are widely used as preservatives in acidic foods like fruit juices and squashes. They work by inhibiting the growth of yeasts and bacteria. Benzene and benzamine are not used as food additives due to toxicity.

During anaerobic respiration, yeast cells convert sugars into ethanol (ethyl alcohol) and carbon dioxide. This process is known as alcoholic fermentation. Methyl alcohol is toxic and is not the product of standard yeast fermentation.

Diplococcus pneumoniae, also known as Streptococcus pneumoniae, is the primary bacterium responsible for bacterial pneumonia. Mycobacterium tuberculosis causes tuberculosis, while Vibrio cholerae causes cholera. Bacillus dysenteriae is associated with intestinal infections.

In the baking industry, yeast is added to dough to perform fermentation. As the yeast consumes sugars, it releases carbon dioxide gas as a byproduct. This gas creates bubbles in the dough, causing it to rise and become light and fluffy.

Extracellular digestion occurs when an organism secretes digestive enzymes onto its food source outside its body. The enzymes break down complex molecules into simpler ones, which are then absorbed. This is the primary method used by fungi to obtain nutrients.

Certain species of Aspergillus and Penicillium are utilized in industrial microbiology to produce microbial fats or lipids. Conversely, yeasts are frequently cultivated as a source of single-cell protein (SCP). This distinction highlights the diverse industrial applications of different fungi.

Fungi and bacteria are the primary decomposers in terrestrial ecosystems. They break down complex organic matter from dead plants and animals into simpler inorganic nutrients. This process is essential for nutrient cycling and maintaining soil fertility.

Ethnomycology is the study of the historical uses and sociological impact of fungi on human cultures. While mycology is the general study of fungi, ethnomycology specifically looks at the human-fungus relationship. Aerology and bacteriology are unrelated fields.

Food yeast, such as nutritional yeast, is an excellent source of B-complex vitamins, vitamin E, and high-quality proteins. Because of its nutrient density, it is often used as a supplement to treat or prevent vitamin deficiency diseases. Mushrooms also contain vitamins but are not typically the primary source for this specific industrial description.

Tuberculosis is caused by the bacterium Mycobacterium tuberculosis, which primarily attacks the lungs. The other bacteria listed cause different diseases: Bacillus typhosus causes typhoid, Vibrio cholerae causes cholera, and Bacillus dysenteriae causes dysentery.

Lichens are composite organisms resulting from a symbiotic relationship between a fungus and a photosynthetic partner, usually an alga. The fungus provides a protected environment and minerals, while the alga provides food through photosynthesis. This mutualism allows them to survive in harsh environments.

Moulds are saprophytic fungi that grow on a wide variety of organic substrates, including bread, fruit, and leather. They play a major role in decomposition but also cause food spoilage. Streptococcus and Staphylococcus are bacteria, not fungi.

Penicillin is a widely used antibiotic that is effective against many bacterial infections, including pneumonia caused by Streptococcus pneumoniae. It works by interfering with the synthesis of bacterial cell walls. Erythromycin is also used, but Penicillin is the most common answer in this context.

Bread mould (Rhizopus) is an aerobic organism, meaning it requires oxygen to perform cellular respiration and produce energy. While it can tolerate various conditions, it cannot survive or grow effectively in the absence of oxygen. Nitrogen and hydrogen do not support its respiration.

In fungi like Mucor and Rhizopus, the columella is a sterile, dome-shaped structure found at the tip of the sporangiophore. It projects into the sporangium and serves as a support for the developing spores. The sporangium itself is the sac that contains the spores.

Edible mushrooms are valued for their high protein content and significant levels of vitamins, particularly B-complex and vitamin D. They are also low in calories and fats, making them a healthy dietary choice. While they contain minerals, the combination of proteins and vitamins is their most notable nutritional feature.