FEMS 2023 conference - Talk

Untapped biosynthetic potential of Antarctic soil bacteria

Abstract:

Background: The growing problem of antimicrobial resistance drove scientists to explore again natural sources of bioactive secondary metabolites. Antarctica represents an extreme environment colonized by bacteria with unique adaptation mechanisms allowing them to thrive under harsh conditions. Such adaptations include ability to produce secondary metabolites to fight competitors or sustain abiotic stresses, which predestines these microbes as source of natural products for biomedical use.

Objectives: The aim of this work was to recover novel bacterial taxa from Antarctic soils to access biosynthetic potential hidden in yet uncultivated bacteria. Main goal lies in activation of silent/cryptic biosynthetic genes enabling discovery of novel secondary metabolites, mainly through co-cultivation strategies.

Methods: Three isolation methods have been applied to recover novel bacteria from Antarctic soils, predominantly targeting phyla with high biosynthetic potential. Activation of silent/cryptic biosynthetic genes was accomplished through targeted cultivation and co-cultivation. Further application of genomics, metabolomics and bioactivity testing aimed to facilitate screening for bioactive molecules and evaluation of their novelty.

Results: A collection of 917 isolates was established. Recovered isolates were associated with four bacterial phyla, out of which 77 belonged to novel taxa. Pseudomonadota and Actinomycetota represented the most abundant phyla exhibiting the highest biosynthetic potential. Targeted cultivation successfully stimulated biosynthesis of several strains. Out of these, 8 strains were confirmed to produced antimicrobial compounds against resistant and multidrug-resistant pathogens including MRSA, LNVRE, ESBL-producers or fully resistant Acinetobacter baumanii. Importantly, metabolomic profiling defined several new secondary metabolites produced by these strains, which may be responsible for detected antimicrobial activities.

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