How do scientists study microbial communities?

Nov 24, 2020

From petri dish to metagenomics

When scientists understood the importance of microbes, they started to design techniques to study them in the lab. They used microscopy to study their physical forms and culture techniques to categorize them.

These traditional techniques have taught us a lot and are still used today, but they provide a very limited vision of the microbial world. Recently, thanks to the advances of high-throughput DNA sequencing, microbiologists have made a giant leap: metagenomics¹!

Today, cultural and metagenomics approaches are complementary. What characterizes metagenomics techniques:

• They allow scientists to detect rare bacteria species and ones that cannot be cultivated
• They enable the analysis of a large number of microbial samples at the same time
• They give us a snapshot of population diversity within a sample

These techniques require very specific expertise in biostatistics and important bioinformatics resources to translate the millions of DNA sequences into microbial population composition. They also rely on a specific database of known bacteria sequences, while a large proportion is still unknown.

The rapid and substantial cost reduction in next-generation sequencing has dramatically accelerated the development of sequence-based metagenomics.