Which term refers to a non-harmful bacteria?

The term that refers to non-harmful bacteria is saprophytes. These bacteria play a vital role in the ecosystem by decomposing organic matter and recycling nutrients back into the environment. Saprophytes contribute to soil health and the breakdown of dead matter, making them essential for maintaining ecological balance.

This contrasts with pathogenic bacteria, which can cause disease and harm host organisms, indicating a significant difference between harmful and non-harmful types of bacteria. Aseptic refers to techniques used to prevent contamination by pathogenic organisms. Invasive typically describes species or organisms that are not native to a specific location and that can cause harm by disrupting local ecosystems. Thus, saprophytes are recognized for their beneficial role in nature, underscoring why this option is the correct choice.