Final answer:
Biofilm formation by Pseudomonas bacteria on a loofa sponge is an example of commensalism, where the bacteria benefit from the environment provided by the sponge without affecting it.
Step-by-step explanation:
The biofilm formation by Pseudomonas bacteria on the surface of a natural loofa sponge is an example of the symbiotic relationship known as commensalism. In commensal relationships, one organism benefits while the other remains unaffected. The Pseudomonas bacteria benefit from the moist environment provided by the loofa sponge which facilitates their growth and biofilm production, while the loofa itself does not benefit from the presence of the bacteria, nor is it harmed.
Biofilms provide various advantages to bacteria such as Staphylococcus aureus, including protection from environmental stresses, such as desiccation and the use of antimicrobials. They can be composed of single or multiple species of microorganisms that secrete a protective and adhesive matrix. In biofilms, bacteria such as Pseudomonas aeruginosa can communicate and coordinate their actions through a process known as quorum sensing, which ensures their survival and resilience against external threats.