Search

Functional metagenomics is an essential and effective approach to recover new enzymes from the environment. In this chapter, we describe a procedure to construct metagenomic library to discover new N-acyl homoserine lactone (AHL) degrading enzymes based on a direct method or an indirect enrichment procedure. Applicable to any bacterial ecosystem, it enables rapid identification of functional enzymes effective to degrade AHLs., (© 2023. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

A collection of mycorrhizal and nonmycorrhizal root-associated fungi coming from forest environments was screened for their ability to degrade N-acyl homoserine lactones (AHL) or to prevent AHL recognition by producing quorum sensing inhibitors (QSI). No production of QS-inhibitors or -activators was detected using the two biosensors Chromobacterium violaceum CV026 and Agrobacterium tumefaciens in the culture supernatant of these fungi. However, the ability to degrade C6- and 3O,C6-HSL was detected for three fungal isolates. Acidification assay revealed that the AHL were degraded by a lactonase activity for two of these isolates. These results demonstrated for the first time that the forest root-associated fungi are capable of degrading the AHL signal molecules.