Metagenomics is the study of microbial communities directly in their natural environments, includingmouth, skin, and gut samples to understand human related diseases, soil samples to study plant soil-microbe interactions, and water samples. A sample can contain more than 10,000 species, but how quantify statistically?Concepts like microbiota, metagenome and microbiome are a bit confusing, microbiota refers to taxonomically identification the community of microorganisms; the metagenome conforms the genes and genomes of the microbiota, including plasmids, and highlights the genetic potential of the population; whereas the microbiome refers to the whole conjunct of genes and genomes of the microbiota, as well as the products of the microbiota and the host environment. This short book tries to put light on the Taxonomic Diversity and its measurement using metagenomics, about the statistical methods and the methodologies.

Microorganisms comprise the greatest genetic diversity in the natural ecosystem, and characterization of these microbes is an essential step towards discovering novel products or understanding complex biological mechanisms. The advancement of metagenomics coupled with the introduction of high-throughput, cost-effective NGS technology has expanded the possibilities of microbial research in various biological systems. In addition to traditional culture and biochemical characteristics, omics approaches (metagenomics, metaproteomics, and metatranscriptomics) are useful for analyzing complete microbial communities and their functional attributes in various environments. Metagenomics and Microbial Ecology: Techniques and Applications explores the most recent advances in metagenomics research in the landscape of next-generation sequencing technologies. This book also describes how advances in sequencing technologies are used to study invisible microbes as well as the relationships between microorganisms in their respective environments. Features: Covers a wide range of concepts, investigations, and technological advancement in metagenomics at the global level. Highlights the novel and recent approaches to analyze microbial diversity and its functional attributes. Features a range of chapters that present an introduction to the field and functional insight into various ecosystems.

Shotgun metagenomics has provided a relatively new and powerful approach to study the environmental samples to characterize the microbial communities in contrast to pure cultures by conventional techniques. To determine the microbial diversity and to understand the role of microbes in the ecosystem, quantitative studies are important whose values are comparable across different studies and samples. We have developed a statistical approach to microbial profiling which encompasses quantitative characterization and comparison of relative abundance of the microbes in a metagenome sample based on their signature sequences (unique k-mers). We demonstrated the utility of this approach by characterizing and quantifying the relative abundance of the microbes in 4 different simulated metagenome samples (Comp_25, Comp_50, Comp_75, and Comp_100). The suffix of simulated metagenome name represents the gene content percentage of reporter species in the simulated metagenomes. The analysis of simulated metagenomes for data volume 6e9 and 6e10 furnish the information about the abundance of species by identifying the unique k-mers (signature sequences) of the six reporter species B. licheniformis, L. brevis, L. fermentum, L. plantarum, P. ananatis, and P. vagans. Our developed approach has efficiently identified the abundance of 4 reporter species i.e. B. licheniformis, L. brevis, L. fermentum, P. ananatis whereas 2 species L. plantarum and P. vagans were overestimated in the simulated metagenomes. So, application of advanced statistics, refinement of the algorithm, and an increase in data volume would be our next steps to improve the accuracy of our approach to estimate the ratio of species of a metagenome.

This volume describes different sequencing methods, pipelines and tools for metagenome data analyses. Chapters guide readers through quality control of raw sequence data, metagenomics databases for bacterial annotations such Greengenes, SILVA, RDP and GTDB, guide to 16S rRNA microbiome analysis and pipelines such as mothur, DADA2, QIIME2 , whole genome shotgun metagenomics data analyses pipeline using MEGAN and DIAMOND, web service such as PATRIC, RDP, mothur, Kaiju, PhyloPythiaS, MG-RAST, WebMGA, MicrobiomeAnalyst, WHAM!, METAGENassist and MGnify: EBI-Metagenomics, MG-RAST Metagenomics Analysis. Then the chapters inform the readers regarding Third-generation sequencing (TGS) approaches as MinION sequencing and teaches use of Ubuntu Linux Virtual Machine configuration, clinical and environmental resistomes, use of FISH techniques and designing FISH probes, protocols for viral metagenomics, and comprehensive guideline for microbiome analysis using most used R packages. Written in the format of the highly successful Methods in Molecular Biology series, each chapter includes an introduction to the topic, lists necessary materials and methods, includes tips on troubleshooting and known pitfalls, and step-by-step, readily reproducible protocols. Authoritative and cutting-edge, Metagenomic Data Analysis: Methods and Protocols aims to be comprehensive guide for researchers to specialize in the metagenomics field.

Environmental DNA (eDNA) refers to DNA that can be extracted from environmental samples (such as soil, water, feces, or air) without the prior isolation of any target organism. The analysis of environmental DNA has the potential of providing high-throughput information on taxa and functionalgenes in a given environment, and is easily amenable to the study of both aquatic and terrestrial ecosystems. It can provide an understanding of past or present biological communities as well as their trophic relationships, and can thus offer useful insights into ecosystem functioning. There is nowa rapidly-growing interest amongst biologists in applying analysis of environmental DNA to their own research. However, good practices and protocols dealing with environmental DNA are currently widely dispersed across numerous papers, with many of them presenting only preliminary results and using adiversity of methods. In this context, the principal objective of this practical handbook is to provide biologists (both students and researchers) with the scientific background necessary to assist with the understanding and implementation of best practices and analyses based on environmentalDNA.

Functional Metagenomics: Microbial Diversity, Interaction, and Application in Bioremediation uses a 20-chapter, easy-to-understand format to centralize the practical application ideas for functional metagenomics. This important resource not only includes chapters on next-generation sequencing technologies to study important biogeochemical cycles, degradation pathways and detoxification, but also gives insight into several tools that have been developed to integrate metadata and sequence data, allowing downstream comparative analyses of different datasets using several ecological indices.Content further explains the newly developed techniques for sequencing DNA; generating shorter fragments than Sanger sequencing techniques to quickly read larger sequences in a shorter amount of time. The content finally explores the role of metagenomics in studying microbial diversity, interaction and application in bioremediation studies and gives the reader overall detailed information regarding metagenomics, its application as well as techniques. Provides comprehensive information to readers on state-of-the-art applications in metagenomics Summarizes our current knowledge of the use of metagenomics and gives a novel and powerful insight into the already existing bioremediation process Gives an overall picture of metagenomics, its application, processes, and future prospects in the field of bioremediation

La metagenòmica és l'estudi genètic d'una comunitat microbiana, i per tant s'hi inclouen totes les espècies que hi habiten, generant així perfils de diversitat biològica.L'anàlisi de les dades obtingudes proporcionen una quantitat desorbitada d'informació, que serà tractada amb eines bioinformàtiques.GAIA és una plataforma web que permet realitzar l' anàlisis de dades metagenòmiques, metatranscriptòmiques i amplicon de manera simplificada per a l'usuari.* Amplicon: s'usa un gen diana com 16s rRNA.* Metagenòmics: tot el genoma de la mostra, DNA.* Metatranscriptòmics: tots els transcriptomes