Increasing our knowledge of bacterial diversity in Antarctica

In just 1 gram of soil we can find the equivalent of 100 million bacteria. Globally much of this bacterial diversity is still poorly known and in extreme environments such as Antarctica it is even less known.

In addition to being responsible for biochemical processes essential to the proper functioning of the ecosystem, bacteria have a great biotechnological potential as they are capable of producing compounds with medicinal properties of interest to the pharmaceutical industry. DNA sequencing techniques allow us to identify which groups of bacteria are present at a site and to understand their distribution in the environment. But for studies of biotechnological potential, their isolation, cultivation and laboratory maintenance are essential. However, for most species, isolation and cultivation in the laboratory has still not been achieved.

For this reason, in our study we used a combined approach of DNA sequencing techniques and new bacterial isolation and culture techniques to study the diversity of two biotechnologically important bacterial groups - Actinobacteria and Cyanobacteria.

This study demonstrated the importance of combining cultivation and sequencing techniques as cultivation methods were able to detect Actinobacteria and Cyanobacteria that were not detected with sequencing methods. The new cultivation techniques were able to recover not only rare species but also possible new species, with potential for future biotechnological applications.

Thus, by combining both approaches, this study was able to increase our knowledge about the bacterial species of the Antarctic McMurdo Dry Valleys and point out ways for their future use.

Bacterial diversity in the land of Victoria in Antarctica | Sampling locations T1 to T6 were chosen following a gradient of lower water availability as they move away from Lake Vida and the END sample represents a rock formation. The abundance of bacteria not identified by DNA sequencing methods was high in almost all samples; for some of these unidentified bacteria isolation and laboratory cultivation was achieved.

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Source:

Rego A, Raio F, Martins TP, Ribeiro H, Sousa AGG, Séneca J, Baptista MS, Lee CK, Cary SC, Ramos V, Carvalho MF, Leão PN, Magalhães C (2019) Actinobacteria and Cyanobacteria Diversity in Terrestrial Antarctic Microenvironments Evaluated by Culture-Dependent and Independent Methods. Front. Microbiol. 10:1018.

doi: 10.3389/fmicb.2019.01018

Authors: Adriana Rego & Mafalda Baptista