Abstract The use of yeasts has been explored as an efficient alternative to fungicide application in the treatment and prevention of post-harvest fruit deterioration. Here, we evaluated the biocontrol abilities of the Antarctic yeast strain Debaryomyces hansenii UFT8244 against the post-harvest phytopathogenic fungi Botrytis cinerea and Rhizopus stolonifer for the protection and preservation of strawberry fruit. The strongest inhibition of germination of B. cinerea (57%) was observed at 0 °C, followed by 40% at 25 °C. In addition, germ tubes and hyphae of B. cinerea were strongly surrounded and colonized by D. hansenii. Production of the enzymes β-1,3-glucanase, chitinase and protease by D. hansenii was detected in the presence of phytopathogenic fungus cell walls. The activity of β-1,3-glucanase was highest on day 12 of incubation and remained high until day 15. Chitinase and protease activities reached their highest levels on the day 15 of incubation. D. hansenii additionally demonstrated the ability to resist oxidative stress. Our data demonstrated that the main biocontrol mechanisms displayed by D. hansenii were the control of phytopathogenic fungal spore germination, production of antifungal enzymes and resistance to oxidative stress. We conclude that isolate D. hansenii UFT8422 should be further investigated for use at commercial scales at low temperatures.

Abstract Polar marine macroalgae thrive in extreme conditions, often displaying geographic isolation and high degree of endemism. The “phycosphere” refers to the zone around the algae inhabited by microrganisms. Our study used DNA metabarcoding to survey the eukaryotic communities associated with seven seaweed species obtained at King George Island (South Shetland Islands, maritime Antarctic), including two Rhodophyta, two Chlorophyta and three Phaeophyceae. The ITS2 region was used as a barcode and our analysis yielded 77 eukaryotic ASVs spanning five Kingdoms (Fungi, Metazoa, Chromista, Protozoa, and Viridiplantae) and ten phyla (Ascomycota, Basidiomycota, Cercozoa, Ciliophora, Ochrophyta, Amebozoa, Chlorophyta, Rhodophyta, Bryophyta and Cnidaria). Additionally, we identified 14 potential new occurrence records for Antarctica. Ciliates and green algae were the most species-rich groups. The most abundant assigned associated species was Monostroma angicava (Chrorophyta). Within the macroalgal, the Chlorophyceans Ulothrix sp. hosted the greatest number of taxa, followed by Monostroma hariotii. Our data suggested that Antarctic macroalgae host a rich diversity of associated organisms and the biodiversity associated with the phycosphere remains underestimated.

Abstract Microbial therapeutic enzymes are the protagonists in the pharmacological treatment of different human diseases. The intrinsic enzymatic characteristics, such as high affinity and specificity to the corresponding substrate, enable effective therapies, with minimal adverse effects and complete remission. However, immunogenicity, short half-life, low enzymatic yield, and low selectivity regarding available enzyme drugs are currently the main obstacles to their development and the broad adherence to therapeutic protocols. By harboring adapted and still unexplored microbial life, environments of extreme conditions, such as Antarctica, become especially important in the prospecting and development of new enzymatic compounds that present higher yields and the possibility of genetic improvement. Antarctic microorganisms have adaptation mechanisms, such as more fluid cell membranes, production of antifreeze proteins and enzymes with more malleable structures, more robust, stable, selective catalytic sites for their respective substrates, and high antioxidant capacity. In this context, this review aims to explore enzymes synthesized by bacteria and fungi from Antarctica as potential drug producers, capable of providing therapeutic efficacy, less adverse effects, and lower production costs with highlight to L-Asparaginase, collagenase, superoxide dismutase and ribonucleases. In addition, this review highlights the unique biotechnological profile of these Antarctic extremophile microorganisms.

Abstract Currently, antimicrobial resistance has become a global public health problem, which has made the need for new antimicrobial compounds to deal with resistant infections an emergency. However, environments that once offered so many innovative molecules, now already exhaustively exploited, do not meet this need. In this context, a geographically isolated, under-explored and extreme environment, such as Antarctica, which holds organisms with unique physiological and biochemical characteristics, assumes great importance as a potential source of new compounds with antimicrobial activity. In this patent review, we investigate the state of technological development in the field of antimicrobial compounds obtained from Antarctic organisms, highlighting the main countries and researchers active in the field, the species utilized, the compounds obtained, and their possible therapeutic applications. As results, few patent documents were found, however they encompass a wide diversity of compounds and species, indicating a great antimicrobial potential present in Antarctic biota, including compounds active against the most important human pathogenic microorganisms, such as including methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus spp. and multi-resistant Mycobacterium tuberculosis. Furthermore, due to the increasing trend in patent applications, a significant rise in the number of patents in this area is expected in the coming years.

Abstract In the Antarctic environment, yeasts are versatile eukaryotes that have shown wide dispersion in different substrates, producing active enzymes in extreme conditions, but their relevance in biotechnological applications is largely unknown. The aim of this study was to evaluate the production of extracellular hydrolases by yeasts isolated from Antarctic lichens and molecularly identify these isolates. From a total of 144 isolates on the screening, 109 (76%) produced at least one of the hydrolases tested, with most activities for proteases 59 (41%), cellulases 58 (40%), esterases 57 (39%), lipases 29 (20%), amylases 23 (16%) and pectinases 20 (14%). Among these isolates, 76 were identified, most belonged to the phylum Basidiomycota (n=73) with the dominance of Vishniacozyma victoriae (n=27), Cystobasidium alpinum (n=3), Mrakia niccombsii (n=3), Cystobasidium laryngis (n=2), Bannozyma yamatoana (n=2), Holtermanniella nyarrowii (n=2), and Glaciozyma martinii (n=2). This study is the first one reporting extracellular enzyme production by yeasts isolated from thallus of the species of Antarctic lichens Lecania brialmontii, Polycauliona candelaria, Usnea capillacea, Cladonia metacorallifera, and Polycauliona regalis. With these data, it’s possible to confirm lichens as a source of hydrolase-producing yeasts, reinforcing the potential of these microorganisms in bioprospecting studies of catalytic molecules from polar regions that may be useful in promising biotechnological applications.

ABSTRACT This work presents the methodology, development and testing of an autonomous system, based on Artificial Neural Networks (ANN), for the reduction of technical losses in reticulated underground systems through the optimal control of the capacitor banks (CBs) present in the grid. The proposed methodology includes Smart Grid features, including practical solutions for current transformers positioning in underground networks, collecting field measurements for the Distribution Operation Centre (DOC) and real-time control of field equipment (capacitors banks). The steps of the proposed methodology and the main aspects of the development of the system are also described, as well as the tests performed to prove the results and validate the system.

Introduction There are few studies reporting the antifungal activities of Lippia alba extracts. Methods A broth microdilution assay was used to evaluate the antifungal effects of Lippia alba extracts against seven yeast species of Candida and Cryptococcus. The butanol fraction was investigated by gas chromatography-mass spectrometry. Results The butanol fraction showed the highest activity against Candida glabrata. The fraction also acted synergistically with itraconazole and fluconazole against C. glabrata. The dominant compounds in the butanol fraction were 2,2,5-trimethyl-3,4-hexanedione, 3,5-dimethyl-4-octanone and hexadecane. Conclusions The butanol fraction may be a good candidate in the search for new drugs from natural products with antifungal activity.

Two Atlantic Rain Forest fragments in Minas Gerais state were studied to access their Agaricales fungal richness. A total of 187 specimens were collected and 109 species, 39 genera, and eight families were identified. Thirty-three species were cited for the first time in Brazil.

The fungus Lentinus strigosus (Pegler 1983) (Polyporaceae, basidiomycete) was selected in a screen for inhibitory activity on Trypanosoma cruzi trypanothione reductase (TR). The crude extract of L. strigosus was able to completely inhibit TR at 20 µg/ml. Two triquinane sesquiterpenoids (dihydrohypnophilin and hypnophilin), in addition to two panepoxydol derivatives (neopanepoxydol and panepoxydone), were isolated using a bioassay-guided fractionation protocol. Hypnophilin and panepoxydone displayed IC50 values of 0.8 and 38.9 µM in the TR assay, respectively, while the other two compounds were inactive. The activity of hypnophilin was confirmed in a secondary assay with the intracellular amastigote forms of T. cruzi, in which it presented an IC50 value of 2.5 µ M. Quantitative flow cytometry experiments demonstrated that hypnophilin at 4 µM also reduced the proliferation of human peripheral blood monocluear cells (PBMC) stimulated with phytohemaglutinin, without any apparent interference on the viability of lymphocytes and monocytes. As the host immune response plays a pivotal role in the adverse events triggered by antigen release during treatment with trypanocidal drugs, the ability of hypnophilin to kill the intracellular forms of T. cruzi while modulating human PBMC proliferation suggests that this terpenoid may be a promising prototype for the development of new chemotherapeutical agents for Chagas disease.

A total of 103 isolates of basidiomycetes, representing 84 species from different Brazilian ecosystems, were evaluated for their antifungal and antibacterial activity in a panel of pathogenic and non-pathogenic microorganisms. Tissue plugs of the fruiting bodies were cultivated in liquid media and the whole culture extracted with ethyl acetate. Crude extracts from Agaricus cf. nigrecentulus, Agrocybe perfecta, Climacodon pulcherrimus, Gloeoporus thelephoroides, Hexagonia hydnoides, Irpex lacteus, Leucoagaricus cf. cinereus, Marasmius cf. bellus, Marasmius sp., Nothopanus hygrophanus, Oudemansiella canarii, Pycnoporus sanguineus, Phellinus sp., and Tyromyces duracinus presented significant activity against one or more of the target microorganisms. Eight isolates were active only against bacteria while three inhibited exclusively the growth of fungi. Two extracts presented wide antimicrobial spectrum and were active against both fungi and bacteria. Differences in the bioactivity of extracts obtained from isolates from the same species were observed.