Yeast is a facultative anaerobe. This means that alcohol fermentation takes place only if:
- the temperature is close to 37°C
- the atmosphere does not contain oxygen
- sugar is provided to the cells
- light is provided to the cells
The advantage of yeast cells over bacterial cells to express human proteins is that:
- yeast cells grow faster
- yeast cells are easier to manipulate genetically
- yeast cells are eukaryotic and modify proteins similarly to human cells
- yeast cells are easily lysed to purify the proteins
Why are fungal insecticides an attractive alternative to chemical pesticides for growing food crops?
- Human consumption of fungal insecticides would not make a person sick, but ingestion of chemical pesticides can be harmful to humans.
- A single fungal insecticide would kill a wider variety of insects than a chemical pesticide.
- Fungal insecticides can eliminate both harmful insects and plant pathogens, while chemical pesticides only kill insects.
- Fungal insecticides will decompose dying plants, enhancing the nitrogen content of the soil, while chemical pesticides are not decomposers.