This volume provides up-to-date and novel techniques for various screening technologies currently used in metagenomics and related areas. Starting with DNA/RNA isolation from environmental samples, the book continues by delving into areas such as current methods used to isolate DNA and construct metagenomic libraries, establishment of metagenome libraries in non-E. coli hosts, and topics like function-driven mining of metagenomic DNA, screening and analyzing protocols for a wide array of different genes encoding enzymes, bacterial viruses and much more. Written for the highly successful Methods in Molecular Biology series, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step and readily reproducible protocols, and tips on troubleshooting and avoiding known pitfalls. Authoritative and practical, Metagenomics: Methods and Protocols, Third Edition provides a comprehensive collection of up-to-date metagenome protocols and tools for the recovery of many major types of biocatalysts and allows for the easy setup of these screens in microbiology laboratories.