Name a microbe used for the production of swiss cheese.
Cheese is formed by partial degradation of milk by different microorganisms. Swiss cheese is formed by the bacterium Propionibacterium sharmanii. Its characteristic feature is formation of large holes due to production of large amount of $\mathrm{CO}_2$.
Why are flocs important in biological treatment of waste water?
Flocs are masses of bacteria associated with fungal filaments that form mesh like structures. These are important in biological treatment of waste water, as they help in digestion of organic matter, remove pathogens and release nutrients in the sewage effluent.
How has the bacterium Bacillus thuringiensis helped us in controlling caterpillars of insect pests?
Bacillus thuringiensis produces an are endotoxin which, when ingested and released in the gut of the larvae of insect pest disrupts the insect gut lining thereby killing them.
How do mycorrhizal fungi help the plants harbouring them?
The mycorrhizal fungi absorb phosphorus from the soil and transfer them to the host cells. They also impart resistance to host plants against root pathogens. They also show tolerance to salinity and draught as well as increases overall growth and development of plant.
Hence, fungal hyphae help in synthesising organic food and also recieve/get shelter and nourishment from the higher plant.
Why are cyanobacteria considered useful in paddy fields?
Cyanobacteria like Anabaena, Nostoc, Oscillatoria serve as an important biofertiliser in paddy fields as they fix atmospheric nitrogen and add organic matter to the soil and increase its fertility.