Quorum Sensing

Chapter 10

Detection and Quantification of Butyrolactones

fromStreptomyces

Marc Biarnes-Carrera, Rainer Breitling, and Eriko Takano

Abstract

InStreptomyces, the onset of antibiotic production and sporulation is coordinated through small diffusible
molecules known asγ-butyrolactones (GBLs). These are active in very low amounts, and their extraction
and characterization are challenging. Here we describe a rapid, small-scale method for the extraction of
GBL fromStreptomyces coelicolor, from both solid and liquid cultures, which provides sufficient material for
subsequent bioassays and partial characterization. We also present two different bioassay techniques for the
detection and quantification of the GBL content in the extracts: the antibiotic bioassay and the kanamycin
bioassay.

Key wordsGamma-butyrolactones, Antibiotic bioassay, Kanamycin bioassay, Small-scale gamma-

butyrolactone extraction, Antibiotic production regulation

1 Introduction

TheStreptomyces species undergo a complex life cycle and are

prolific producers of a battery of clinically relevant compounds

[1]. The onset of secondary metabolite production and/or mor-

phological differentiation occurs at the transition from vegetative

growth to stationary phase and is coordinated by bacterial hor-

mones known asγ-butyrolactones (GBLs) [2]. Biosynthesis of

GBLs occurs at the nanomolar scale and involves a first condensa-

tion of dihydroxyacetone phosphate with a beta-ketoacid [3],

which can be followed by further modifications by tailoring

enzymes [4]. The final GBLs are known to interact with DNA-

binding repressors, known as ScbR inS. coelicolor, that act as master

regulators of the primary cascade leading to secondary metabolite

production.

Currently, at least 15 different GBLs have been isolated and

characterized from differentStreptomycesspecies [2], as well as

Livia Leoni and Giordano Rampioni (eds.),Quorum Sensing: Methods and Protocols, Methods in Molecular Biology,
vol. 1673,https://doi.org/10.1007/978-1-4939-7309-5_10,©Springer Science+Business Media LLC 2018

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