New prospects and problems in sample preparation methods for microbiome analysis

Since the discovery of the first bioactive compounds from microorganisms, interest in these systems has gradually increased. Microorganisms have been considered an essential source for biomolecules with several applications such as new drugs, biopesticides, etc. One of the significant challenges in microorganism exploration is sample preparation prior to instrumental analysis, which involves extraction and clean-up processes. So far, conventional sample preparation techniques such as solid phase extraction (SPE), liquid-liquid extraction (LLE), and solvent extraction (SE) are still widespread in microbiological research. Although they present several disadvantages compared to modern methods, they continue being used. Thus, microextraction techniques in this field can be employed to overcome several limitations of conventional methods. This review presents the advantages of microextraction as well as examples of its application to encourage the use of microextraction techniques. In addition to recent applications, basic theory that indicates which kind of strategies can favor a more profound knowledge of these highly complex systems is also discussed. Indeed, appropriate sample preparation techniques can support the understanding of these systems and promote the discovery of new molecules. (C) 2021 Elsevier B.V. All rights reserved.