Optimization of Microbial DNA Extraction from Wine, Juice, and Sap for Community-Based Genome Studies

Obtaining high-quality DNA for diversity analysis from plant-based samples is challenging due to the presence of inhibitors, such as phenolics which are naturally abundant in plant tissues. Phenolics can hinder DNA extraction processes causing degradation, enzymatic inhibition, and oxidation, leading to low yield and purity DNA for analysis of microbial communities. Modifying the extraction method by performing a pre-treatment step to reduce the concentration of phenolics will be crucial before the extraction process of plant-based samples. Here we describe the addition of polyvinylpolypyrrolidone (PVPP) to bind phenolics, which is then discarded from the extraction process. DNA extraction process is completed by following commercially available extraction kits for efficient release of high-quality DNA for downstream analyses. This method can be used for extracting DNA from plant-derived liquids (grape juice, must, wine; also xylem/phloem sap inside the plant) for genomic studies.