Lecture

Microbial Community Analysis: Methods and Applications

Graph Chat

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

Description

This lecture covers the methods used in microbial ecology to analyze microbial communities, including culture-dependent and culture-independent techniques. It discusses the application of fluorescence in situ hybridization (FISH) for visualizing specific microbial species, genetic analyses using PCR, and the use of stable isotopes to study microbial transformations. The lecture also explores techniques like microsensors, flow cytometry, and single-cell genomics to link microbial functions to individual cells. Various case studies and examples are presented to illustrate the practical applications of these methods in studying microbial activities in nature.

This video is available exclusively on Mediaspace for a restricted audience. Please log in to MediaSpace to access it if you have the necessary permissions.

Watch on Mediaspace

Official source

Related concepts (32)

Stable isotope ratio

The term stable isotope has a meaning similar to stable nuclide, but is preferably used when speaking of nuclides of a specific element. Hence, the plural form stable isotopes usually refers to isotopes of the same element. The relative abundance of such stable isotopes can be measured experimentally (isotope analysis), yielding an isotope ratio that can be used as a research tool. Theoretically, such stable isotopes could include the radiogenic daughter products of radioactive decay, used in radiometric dating.

Isotope geochemistry

Isotope geochemistry is an aspect of geology based upon the study of natural variations in the relative abundances of isotopes of various elements. Variations in isotopic abundance are measured by isotope ratio mass spectrometry, and can reveal information about the ages and origins of rock, air or water bodies, or processes of mixing between them. Stable isotope geochemistry is largely concerned with isotopic variations arising from mass-dependent isotope fractionation, whereas radiogenic isotope geochemistry is concerned with the products of natural radioactivity.

Isotope analysis

Isotope analysis is the identification of isotopic signature, abundance of certain stable isotopes of chemical elements within organic and inorganic compounds. Isotopic analysis can be used to understand the flow of energy through a food web, to reconstruct past environmental and climatic conditions, to investigate human and animal diets, for food authentification, and a variety of other physical, geological, palaeontological and chemical processes.

Isotopic signature

An isotopic signature (also isotopic fingerprint) is a ratio of non-radiogenic 'stable isotopes', stable radiogenic isotopes, or unstable radioactive isotopes of particular elements in an investigated material. The ratios of isotopes in a sample material are measured by isotope-ratio mass spectrometry against an isotopic reference material. This process is called isotope analysis. The atomic mass of different isotopes affect their chemical kinetic behavior, leading to natural isotope separation processes.

Reference materials for stable isotope analysis

Isotopic reference materials are compounds (solids, liquids, gasses) with well-defined isotopic compositions and are the ultimate sources of accuracy in mass spectrometric measurements of isotope ratios. Isotopic references are used because mass spectrometers are highly fractionating. As a result, the isotopic ratio that the instrument measures can be very different from that in the sample's measurement. Moreover, the degree of instrument fractionation changes during measurement, often on a timescale shorter than the measurement's duration, and can depend on the characteristics of the sample itself.

Related lectures (64)

Tracers and Transit Time Distributions

Covers hydrologic transport, water pollution, the EU WATER FRAMEWORK directive, water transit times, stable isotopes, and age balance in hydrologic systems.

Molecular Spectroscopy: Vibrational Modes

Explores molecular spectra, vibrational modes, Schrödinger equation solutions, and isotopic distribution in mass spectrometry.

Proteomics and Mass Spectrometry

Covers the basics of proteomics, mass spectrometry, protein synthesis, and amino acids, emphasizing the importance of molecular weight and isotopic abundance.

Tracers and Water Residence Times

Delves into water residence times, tracers, and hydrologic processes, emphasizing the complexity and variability of water transport.

Protein Mass Spectrometry and Proteomics