Advances in Antarctic Research for Antimicrobial Discovery: A Comprehensive Narrative Review of Bacteria from Antarctic Environments as Potential Sources of Novel Antibiotic Compounds Against Human Pathogens and Microorganisms of Industrial Importance

Abstract

The recent emergence of antibiotic-resistant bacteria has become a critical public health problem. It is also a concern for industries, since multidrug-resistant microorganisms affect the production of many agricultural and food products of economic importance. Therefore, discovering new antibiotics is crucial for controlling pathogens in both clinical and industrial spheres. Most antibiotics have resulted from bioprospecting in natural environments. Today, however, the chances of making novel discoveries of bioactive molecules from various well-known sources have dramatically diminished. Consequently, unexplored and unique environments have become more likely avenues for discovering novel antimicrobial metabolites from bacteria. Due to their extreme polar environment, Antarctic bacteria in particular have been reported as a potential source for new antimicrobial compounds. We conducted a narrative review of the literature about findings relating to the production of antimicrobial compounds by Antarctic bacteria, showing how bacterial adaptation to extreme Antarctic conditions confers the ability to produce these compounds. We highlighted the diversity of antibiotic-producing Antarctic microorganisms, including the phyla Proteobacteria, Actinobacteria, Cyanobacteria, Firmicutes, and Bacteroidetes, which has led to the identification of new antibiotic molecules and supports the belief that research on Antarctic bacterial strains has important potential for biotechnology applications, while providing a better understanding of polar ecosystems.

Keywords: Antarctic bacteria; Antarctic ecosystem; bacterial cold-adaptation; extreme environment; multidrug-resistant pathogens; novel antibiotics.

Figure 1

Chemical structures of molecules with antibiotic activity obtained from Antarctic bacteria: (a) Streptomyces flavovirens, (b) and (c) Flavobacterium sp., (d) Nostoc sp., and (e–g) Pseudomonas sp. All molecules, except (e), correspond to novel antimicrobial metabolites. Modified from: [23,54,62,72].

Figure 2

Reported diversity of Antarctic bacteria producing antimicrobial compounds and the geographical locations where diverse sample types were collected for isolation. Different phyla diversity has been reported for west and east Antarctic (a); each phylum has been reported with different frequency for the west side (b) compared to the east counterpart (e). Geographical locations where bacteria with antimicrobial activity have been isolated at each Antarctic side are shown, indicating that the west side has been less explored (d). Blue marks represent regions where punctual sampling was executed; green marks joined by a line illustrate two studies [14,17] where the complete area was sampled; the amplified squares show regions with multiple sampling sites. Active strains have been isolated utilizing different sample sources for west (c) and east (f) continent sides, including soil and seawater for both areas, and freshwater and microbial mats on the west side.