Fast quantitative determination of microbial rhamnolipids from cultivation broths by ATR-FTIR Spectroscopy.

Frank Leitermann,Rudolf Hausmann,Christoph Syldatk

doi:10.1186/1754-1611-2-13

Abstract

BackgroundVibrational spectroscopic techniques are becoming increasingly important and popular because they have the potential to provide rapid and convenient solutions to routine analytical problems. Using these techniques, a variety of substances can be characterized, identified and also quantified rapidly.ResultsThe rapid ATR-FTIR (Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy) in time technique has been applied, which is suitable to quantify the concentrations of microbial rhamnolipids in a typical cultivation process. While the usually applied HPLC analysis requires an extensive and time consuming multi step extraction protocol for sample preparation, the ATR-FTIR-method allows the quantification of the rhamnolipids within 20 minutes. Accuracies between 0.5 g/l – 2.1 g/l for the different analytes were determined by cross validation of the calibration set. Even better accuracies between 0.28 g/l – 0.59 g/l were found for independent test samples of an arbitrarily selected cultivation.ConclusionATR-FTIR was found to be suitable for the rapid analysis of rhamnolipids in a biotechnological process with good reproducibility in sample determination and sufficient accuracy. An improvement in accuracy through continuous expansion and validation of the reference spectra set seems very likely.

Highlights

Vibrational spectroscopic techniques are becoming increasingly important and popular because they have the potential to provide rapid and convenient solutions to routine analytical problems
Attenuated Total Reflectance (ATR)-Fourier transform infrared spectroscopy (FTIR) was found to be suitable for the rapid analysis of rhamnolipids in a biotechnological process with good reproducibility in sample determination and sufficient accuracy
Typical assays often rely on enzymatic reactions or separation techniques such as high performance liquid chromatography (HPLC) [2]

Summary

Introduction

Vibrational spectroscopic techniques are becoming increasingly important and popular because they have the potential to provide rapid and convenient solutions to routine analytical problems. Using these techniques, a variety of substances can be characterized, identified and quantified rapidly. Ranging from bulk chemicals like ethanol to high value proteins, biotechnological production processes are an increasingly important manufacturing route for various products [1]. The control of these bioprocesses often can be considered as suboptimal. The analysis results often will be available only with a significant time delay

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