Explainer: How bacteria give rain its unique scent

The video explores the unique scent of rain, attributed to geosmin, a chemical produced by Streptomyces bacteria. This scent attracts springtails, small arthropods that consume the bacteria, aiding in the spread of bacterial spores. This mutually beneficial relationship has likely existed for millions of years. Streptomyces produce antibiotics that are harmful to other organisms but not to springtails, suggesting an evolutionary adaptation where springtails have become a key vector for the bacteria's reproduction.

What is the primary cause of the smell of rain?

• Geosmin produced by Streptomyces bacteria

• A chemical reaction in the atmosphere

• Pollen from plants

• Evaporation of water

How do springtails contribute to the spread of Streptomyces?

• By creating tunnels in the soil

• By producing geosmin

• By pollinating flowers

• By carrying spores on their bodies

What is the role of geosmin in the relationship between springtails and Streptomyces?

• It attracts springtails to the bacteria

• It acts as a food source for springtails

• It repels predators of springtails

• It helps in the photosynthesis process

Why are Streptomyces antibiotics not harmful to springtails?

• Springtails have developed resistance over time

• The antibiotics are only produced in small quantities

• The antibiotics are only effective against plants

• Springtails do not consume the bacteria

What evidence suggests a long-standing relationship between springtails and Streptomyces?

• Springtails have been found in ancient fossils

• Streptomyces produce antibiotics that do not harm springtails

• Springtails are the only organisms that consume Streptomyces

• Geosmin is only produced in the presence of springtails