Unraveling the mutation driving increased rhamnolipid production in Pseudomonas aeruginosa LBI 2A1 and its context in quorum sensing

Abstract

Rhamnolipids (RLs) are biosurfactants primarily produced by the bacterium Pseudomonas aeruginosa, exhibiting high surface activity. Their versatile applications stem from properties such as detergent, emulsifying, foaming, and dispersing capabilities. In comparison to chemical surfactants, RLs offer high biodegradability, are derived from renewable sources, exhibit higher specificity, low toxicity, unique structures, high selectivity, and specific activity at extreme temperatures, pH levels, and salinity. Despite these numerous advantages, industrial RL production faces challenges, particularly regarding high production costs. The production of this surfactant is regulated by a cascade quorum sensing system and physicochemical environmental factors. In the Contiero Lab, the mutant strain P. aeruginosa LBI 2A1 has shown promising results in RL production, with a 70% increase compared to the wild-type strain when using hydrophobic sources. However, the location and type of mutation in this microorganism have not been investigated yet-information that could aid in understanding how to optimize cultures for surfactant production. The scale-up to industrial RL production still faces challenges related to low yield and high production costs. Therefore, this research aims to identify the mutation responsible for the increased RL production in 2A1 and study its influence on the quorum sensing system. This involves determining the transposon insertion site in the 2A1 strain, confirming that the specific mutation caused by the transposon is responsible for the enhanced RL production, and elucidating how the mutation affects rhamnolipid production.