This document provides a tutorial on processing 16S metagenomic sequences using mothur, Python and R. It outlines the workflow including data preparation, preprocessing such as denoising and merging files, OTU clustering, classification and downstream analysis. Methods covered include using mothur for alignment, preprocessing, OTU picking and classification, and Python and R scripts for additional processing such as text parsing, normalization and visualization. The document concludes by summarizing the overall workflow and requesting help with further improving and automating the process.