Biofilm interactions between distinct bacterial genera isolated from drinking water

Area of Science:

• Microbiology
• Environmental Science
• Biofilm Research

Background:

• Microorganisms in the environment form complex communities, often as biofilms.
• Understanding inter-species interactions within biofilms is crucial for managing microbial communities, especially in drinking water systems.

Purpose of the Study:

• To investigate single- and dual-species biofilm formation by heterotrophic bacteria from drinking water.
• To identify key bacterial attributes influencing biofilm formation and inter-species interactions.
• To assess the relationship between planktonic characteristics and biofilm behavior.

Main Methods:

• Six heterotrophic intergeneric bacteria isolated from drinking water were used.
• Biofilm formation was quantified in 96-well polystyrene plates over 72 hours.
• Planktonic studies assessed bacterial growth rate, motility, and quorum-sensing inhibitor (QSI) production.

Main Results:

• All isolates formed stable biofilms in pure and dual cultures within 72 hours.
• Specific metabolic activity generally decreased with increased biofilm mass.
• Identified synergistic, antagonistic, and neutral interactions between bacterial pairs, with Methylobacterium sp. and Mycobacterium mucogenicum forming the largest dual biofilm.
• Quorum-sensing inhibitors (QSI) and growth rate influenced some dual-biofilm formations, but planktonic studies could not fully predict these dynamics.

Conclusions:

• Drinking water bacteria form complex biofilms with varied inter-species interactions.
• Biofilm mass and metabolic activity are influenced by species composition and interactions.
• Planktonic traits alone are insufficient to predict the mechanisms governing dual-species biofilm formation in drinking water environments.