Extracellular Enzymes and Bioactive Compounds from Antarctic Terrestrial Fungi for Bioprospecting

Abstract

Antarctica, one of the harshest environments in the world, has been successfully colonized by extremophilic, psychrophilic, and psychrotolerant microorganisms, facing a range of extreme conditions. Fungi are the most diverse taxon in the Antarctic ecosystems, including soils. Genetic adaptation to this environment results in the synthesis of a range of metabolites, with different functional roles in relation to the biotic and abiotic environmental factors, some of which with new biological properties of potential biotechnological interest. An overview on the production of cold-adapted enzymes and other bioactive secondary metabolites from filamentous fungi and yeasts isolated from Antarctic soils is here provided and considerations on their ecological significance are reported. A great number of researches have been carried out to date, based on cultural approaches. More recently, metagenomics approaches are expected to increase our knowledge on metabolic potential of these organisms, leading to the characterization of unculturable taxa. The search on fungi in Antarctica deserves to be improved, since it may represent a useful strategy for finding new metabolic pathways and, consequently, new bioactive compounds.

Diversity, Ecological Role and Biotechnological Potential of Antarctic Marine Fungi

“…Marine extremophilic microorganisms, including fungi, can also represent a huge reservoir of bioactive molecules that have recently triggered interest in bioprospecting research because of their promising therapeutical properties [ 21 , 22 , 29 , 109 , 152 , 155 , 156 , 157 , 158 , 159 ]. In this regard, marine fungi isolated from polar environments reported their ability to synthesize metabolites with unique structures and a wide range of biological activities, compared to mesophilic fungi, highlighting that psychrophilic fungi can be a new resource for several applications in biotechnology [ 28 , 30 , 160 , 161 , 162 ]. However, the search for natural bioactive products has been focused so far on a very small number of fungi isolated from Antarctic marine sediments, seawater and few organisms such as sponges and macroalgae [ 27 ].…”

“…Most of the research on the bioactive compounds carried out in Antarctic environments mainly focus on a few Penicillium strains, leaving most of the actual fungal biodiversity largely unexplored. The bioprospection of psychrophilic and psychrotolerant polar Penicillium strains have resulted in the collection of many promising bioactive molecules with a complex and peculiar structure and a broad range of biological activities, highlighting their outstanding potential [ 162 ]. For instance, eremophilane-type sesquiterpene isolated from Penicillium sp.…”

“…Nowadays, a considerable number of industrial processes and products take advantage of microbial enzymes [ 173 , 174 ]. Nevertheless, studies prospecting and characterizing enzymes have mainly focused on prokaryotes [ 175 , 176 ], while there is little information on enzymes from psychrophilic or psychrotolerant eukaryotes inhabiting Antarctic systems [ 162 , 177 , 178 ].…”

“…Antarctic environments are a relatively new frontier for the isolation of cold-active enzymes. These molecules have distinct features that meet the need of green industry applications [ 162 , 177 , 189 , 190 ]. In this view, psychrophilic and psychrotolerant fungi are specialized in producing extracellular and intracellular cold active-enzymes [ 20 , 189 , 191 ], which they use to live in harsh conditions to degrade molecules and for the uptake of nutrients [ 141 , 170 , 192 , 193 , 194 ].…”

Diesel in Antarctica and a Bibliometric Study on Its Indigenous Microorganisms as Remediation Agent

“…Microorganisms have astonishing adaptation to withstand extreme conditions of their surroundings [ 103 ]. Particularly in Antarctica, indigenous microbes are obligated to cope with subzero temperatures, temperature fluctuations, frequent freeze and thaw process as well as intense solar irradiations [ 104 , 105 ].…”