Identification and characterization of a long-chain 𝘕-acyl homoserine lactone from 𝘙𝘩𝘪𝘻𝘰𝘣𝘪𝘶𝘮 sp. isolated from 𝘡𝘦𝘢 𝘹 𝘮𝘢𝘺𝘴 rhizosphere

Abstract

The microbiological study of maize rhizosphere (𝘡𝘦𝘢 𝘹 𝘮𝘢𝘺𝘴) cultivated in Brazil led to the isolation of a bacterium, which was identified as 𝘙𝘩𝘪𝘻𝘰𝘣𝘪𝘶𝘮 sp. based upon 16 S rRNA analysis. The chemical study of fractions obtained from bacterium extract allowed the identification of the compound N-(3-oxo-tetradec-7-enoyl)- homoserine lactone using uni and bidimensional nuclear magnetic resonance spectroscopy (NMR), gas chromatography coupled to low resolution electron impact mass spectrometry (GC–MS), and ultra-high re solution Qq-time-of-flight mass spectrometry (UHR-QqTOF-MS). Biological assays with the strains 𝘈𝘨𝘳𝘰𝘣𝘢𝘤𝘵𝘦𝘳𝘪𝘶𝘮 𝘵𝘶𝘮𝘦𝘧𝘢𝘴𝘤𝘪𝘦𝘯𝘴 A136 and 𝘊𝘩𝘳𝘰𝘮𝘰𝘣𝘢𝘤𝘵𝘦𝘳𝘪𝘶𝘮 𝘷𝘪𝘰𝘭𝘢𝘤𝘦𝘶𝘮 CV026 were also performed and showed negative results, corroborating the hypothesis of production of only the long chain acyl homoserine lactone (AHL) 1, and the lack of presence of short or medium chain homologues, as observed by instrumental GC–MS and NMR analyses. The chemotaxonomic relevance of the presence of long chain AHL in Rhizobiaceae was discussed.