Enzymes and biosurfactants of industrial interest produced by culturable fungi present in sediments of Boeckella Lake, Hope Bay, north-east Antarctic Peninsula.

This study characterized cultivable fungi present in sediments obtained from Boeckella Lake, Hope Bay, in the north-east of the Antarctic Peninsula, and evaluated their production of enzymes and biosurfactants of potential industrial interest. A total of 116 fungal isolates were obtained, which were classified into 16 genera within the phyla Ascomycota, Basidiomycota and Mortierellomycota, in rank. The most abundant genera of filamentous fungi included Pseudogymnoascus, Pseudeurotium and Antarctomyces; for yeasts, Thelebolales and Naganishia taxa were dominant. Overall, the lake sediments exhibited high fungal diversity and moderate richness and dominance. The enzymes esterase, cellulase and protease were the most abundantly produced by these fungi. Ramgea cf. ozimecii, Holtermanniella wattica, Leucosporidium creatinivorum, Leucosporidium sp., Mrakia blollopis, Naganishia sp. and Phenoliferia sp. displayed enzymatic index > 2. Fourteen isolates of filamentous fungi demonstrated an Emulsification Index 24% (EI24%) ≥ 50%; among them, three isolates of A. psychrotrophicus showed an EI24% > 80%. Boeckella Lake itself is in the process of drying out due to the impact of regional climate change, and may be lost completely in approaching decades, therefore hosts a threatened community of cultivable fungi that produce important biomolecules with potential application in biotechnological processes.

Diversity and enzymatic, biosurfactant and phytotoxic activities of culturable Ascomycota fungi present in marine sediments obtained near the South Shetland Islands, maritime Antarctica.

We studied the culturable fungal community recovered from deep marine sediments in the maritime Antarctic, and assessed their capabilities to produce exoenzymes, emulsifiers and metabolites with phytotoxic activity. Sixty-eight Ascomycota fungal isolates were recovered and identified. The most abundant taxon recovered was the yeast Meyerozyma guilliermondii, followed by the filamentous fungi Penicillium chrysogenum, P. cf. palitans, Pseudeurotium cf. bakeri, Thelebolus balaustiformis, Antarctomyces psychrotrophicus and Cladosporium sp. Diversity indices displayed low values overall, with the highest values obtained at shallow depth, decreasing to the deepest location sampled. Only M. guilliermondii and P. cf. palitans were detected in the sediments at all depths sampled, and were the most abundant taxa at all sample sites. The most abundant enzymes detected were proteases, followed by invertases, cellulases, lipases, carrageenases, agarases, pectinases and esterases. Four isolates showed good biosurfactant activity, particularly the endemic species A. psychrotrophicus. Twenty-four isolates of P. cf. palitans displayed strong phytotoxic activities against the models Lactuca sativa and Allium schoenoprasum. The cultivable fungi recovered demonstrated good biosynthetic activity in the production of hydrolytic exoenzymes, biosurfactant molecules and metabolites with phytotoxic activity, reinforcing the importance of documenting the taxonomic, ecological and biotechnological properties of fungi present in deep oceanic sediments of the Southern Ocean.

Antarctic marine sediment as a source of filamentous fungi-derived antimicrobial and antitumor compounds of pharmaceutical interest.

Antarctica harbors a microbial diversity still poorly explored and of inestimable biotechnological value. Cold-adapted microorganisms can produce a diverse range of metabolites stable at low temperatures, making these compounds industrially interesting for biotechnological use. The present work investigated the biotechnological potential for antimicrobial and antitumor activity of filamentous fungi and bacteria isolated from marine sediment samples collected at Deception Island, Antarctica. A total of 89 microbial isolates were recovered from marine sediments and submitted to an initial screening for L-glutaminase with antitumoral activity and for antimicrobial metabolites. The isolates Pseudogymnoascus sp. FDG01, Pseudogymnoascus sp. FDG02, and Penicillium sp. FAD33 showed potential antiproliferative action against human pancreatic carcinoma cells while showing no toxic effect on non-tumor cells. The microbial extracts from unidentified three bacteria and four filamentous fungi showed antibacterial activity against at least one tested pathogenic bacterial strain. The isolate FDG01 inhibited four bacterial species, while the isolate FDG01 was active against Micrococcus luteus in the minimal inhibitory concentration of 0.015625 µg mL -1. The results pave the way for further optimization of enzyme production and characterization of enzymes and metabolites found and reaffirm Antarctic marine environments as a wealthy source of compounds potentially applicable in the healthcare and pharmaceutical industry.

Bioprospecting the potential of the microbial community associated to Antarctic marine sediments for hydrocarbon bioremediation.

Microorganisms that inhabit the cold Antarctic environment can produce ligninolytic enzymes potentially useful in bioremediation. Our study focused on characterizing Antarctic bacteria and fungi from marine sediment samples of King George and Deception Islands, maritime Antarctica, potentially affected by hydrocarbon influence, able to produce enzymes for use in bioremediation processes in environments impacted with petroleum derivatives. A total of 168 microorganism isolates were obtained: 56 from sediments of King George Island and 112 from Deception Island. Among them, five bacterial isolates were tolerant to cell growth in the presence of diesel oil and gasoline and seven fungal were able to discolor RBBR dye. In addition, 16 isolates (15 bacterial and one fungal) displayed enzymatic emulsifying activities. Two isolates were characterized taxonomically by showing better biotechnological results. Psychrobacter sp. BAD17 and Cladosporium sp. FAR18 showed pyrene tolerance (cell growth of 0.03 g mL-1 and 0.2 g mL-1) and laccase enzymatic activity (0.006 UL-1 and 0.10 UL-1), respectively. Our results indicate that bacteria and fungi living in sediments under potential effect of hydrocarbon pollution may represent a promising alternative to bioremediate cold environments contaminated with polluting compounds derived from petroleum such as polycyclic aromatic hydrocarbons and dyes.

Short-term glacier area changes, glacier geometry dependence, and regional climatic variations forcing, King George Island, Antarctica.

This study investigates the transient snowline (TSL) altitude for summer 2020, as well as glacial area loss in King George Island Icefields since 1988 using Sentinel-1 and 2 and Landsat Thematic Mapper (TM) imagery. Trends and anomalies in atmospheric temperature, U-wind, and V-wind were examined using ERA5 solutions. Results show the wet-snow zone corresponds to values of ≤ -13dB, and 44.3% of the glacial area is located above the TSL (≥ 300 m). Glacial area for 2020 is 999.95 km², and losses in the period represent 104.9 km² (error <1%) - a retreat of 3.17 km² / year. Glaciers in Keller Peninsula and Bellingshausen Dome lost the most area (28% and 17%, respectively) and did not have a TSL in 2020; followed by Warszawa (15%), Kraków (13%), and Eastern (10%), where the TSL was verified. Percentage area loss values increased with decreases in dimensions, area above TSL, and maximum elevation. Calving glaciers with ice-flow toward deeper and steeper submarine sectors (Bransfield Strait) exhibited greater glacier variations. The trend in warming atmospheric temperature was greater in the Bransfield Strait than in the Drake Passage. TSL and retreat difference between glaciers were influenced by climatic and ocean input, as well as multiple environmental factors.

Glacier fluctuations and a proglacial evolution in King George Bay (King George Island), Antarctica, since 1980 decade.

This study aims to investigate the glacier shrinkage and recent proglacial environment in King George Bay, Antarctica, since 1988 in response to climate change. Remote sensing data (SPOT, Sentinel, Landsat and Planet Scope images) were applied to glacial landforms and ice-marginal fluctuations mapping. Annual mean near-surface air temperature reanalysis solutions from ERA-Interim were analyzed. Moraines and glaciofluvial landforms were identified. The Ana Northern Glacier has the highest retreat value (3.64 km) (and area loss of 31%) in response to higher depth in frontal ice-margin and reveal ocean-glacier linkages. The Ana South Glacier changed from a tidewater glacier to land-terminating after 1995, and had an outline minimum elevation variation of 89 meters, a shrinkage of 0.63 km, and a new proglacial subaerial sector. The Ana South Glacier foreland had recessional moraines (probably formed between 1995 and 2022), lagoons, and lakes. There are many flutings in low-relief environments. The 1980-1989, 1990-1999, 2000-2009, 2010-2019 anomaly plots concerning to the 1980-2019 average for atmospheric temperature, are shown to be a driver of the local glacial trends.

Elemental and mineralogical characterization of marine sediments and their relationship to sedimentary and oceanographic processes in Central Bransfield Basin.

This work consists of the sedimentological, mineralogical, and geochemical characterization of eight marine sediment cores collected in the Central Bransfield Basin, along a transect between the South Shetland Islands to the Antarctic Peninsula and its correlation to the sedimentary and oceanographic processes of the area. A chemical characterization based on X-ray fluorescence dispersive spectrometry was implemented to obtain geochemical data of the marine sediment while the minerals were identified by X-ray diffraction. The study allowed to classify the cores into three groups according to their sediment source and chemical and mineralogical characteristics. The joint assessment of the geochemical and mineralogical signature of the sediment has confirmed that the elemental ratios Ti/Ca and Fe/Ca can be applied as proxies in the reconstitution of the terrigenous contribution to the Central Bransfield Basin if we consider the sedimentary contribution of the volcanic edifices present in the region. The Fe/K ratio associated with the Chemical Index of Alteration reinforced an increase in the degree of weathering near South Shetland Island, which is also pointed out by other authors in studies on climate change mainly in the subantarctic islands. The trend of temperature increase implies the importance of monitoring the region.

Fungal and fungal-like diversity in marine sediments from the maritime Antarctic assessed using DNA metabarcoding.

We assessed the fungal and fungal-like sequence diversity present in marine sediments obtained in the vicinity of the South Shetland Islands (Southern Ocean) using DNA metabarcoding through high-throughput sequencing (HTS). A total of 193,436 DNA reads were detected in sediment obtained from three locations: Walker Bay (Livingston Island) at 52 m depth (48,112 reads), Whalers Bay (Deception Island) at 151 m (104,704) and English Strait at 404 m (40,620). The DNA sequence reads were assigned to 133 distinct fungal amplicon sequence variants (ASVs) representing the phyla Ascomycota, Basidiomycota, Mortierellomycota, Chytridiomycota, Glomeromycota, Monoblepharomycota, Mucoromycota and Rozellomycota and the fungal-like Straminopila. Thelebolus balaustiformis, Pseudogymnoascus sp., Fungi sp. 1, Ciliophora sp., Agaricomycetes sp. and Chaetoceros sp. were the dominant assigned taxa. Thirty-eight fungal ASVs could only be assigned to higher taxonomic levels, and may represent taxa not currently included in the available databases or represent new taxa and/or new records for Antarctica. The total fungal community displayed high indices of diversity, richness and moderate to low dominance. However, diversity and taxa distribution varied across the three sampling sites. In Walker Bay, unidentified fungi were dominant in the sequence assemblage. Whalers Bay sediment was dominated by Antarctic endemic and cold-adapted taxa. Sediment from English Strait was dominated by Ciliophora sp. and Chaetoceros sp. These fungal assemblages were dominated by saprotrophic, plant and animal pathogenic and symbiotic taxa. The detection of an apparently rich and diverse fungal community in these marine sediments reinforces the need for further studies to characterize their richness, functional ecology and potential biotechnological applications.

Geomorphology of Martel inlet, King George Island, Antarctica: a new interpretation based on multi-resolution topo-bathymetric data.

This study investigated the terrestrial and submarine geomorphology and glacial landform records in the Martel inlet (King George Island) using a multi-resolution topobathymetric data based on seismic, multibeam surveys and terrestrial satellite datasets (REMA DEM). Geomorphometric analysis provided glacial landforms and sedimentary processes interpretation. The submarine sector has a mean depth of 143 m, a maximum depth of 398 m, and most of it has a low slope (0°-16°). Steep slopes (>30°) are found along the mid-outer sectors transition area. The continental shelf was divided into inner fjord (49 m depth), middle fjord (119 m), and outer fjord (259 m), based on depth, elevation and slope. The topobathymetric digital model provides evidence of geomorphological contrasts between these zones in the fjord's seafloor and subaerial environments. A prominent morainal bank in the transition between the inner and middle parts marks the limit of a past stationary stage of the Dobrowolski-Goetel ice margin. Streamlined glacial lineations demonstrate an NE-SW past ice flow direction and a wet-based thermal regime. The combined analysis of submarine and subaerial landforms enable the understanding of the former glacier configuration and its deglaciation history.

An inventory of glacial lakes in the South Shetland Islands (Antarctica): temporal variation and environmental patterns.

Monitoring and inventorying proglacial lakes in the Maritime Antarctica region is essential for understanding the effects of climate change on these environments. This study uses Landsat images to create a map of lakes in ice-free areas of the South Shetlands Islands (SSI) for 1986/89, 2000/03 and 2020, and verification of patterns of change in lake areas and numbers. Normalized water difference index (NDWI) products, image segmentation, field records, and cartographic products from other studies were used to validate the results. Results show a 60% increase in the number of lakes from 1986/89 to 2000/03; and a 55% increase from 2000/03 to 2020. There was a 52% increase in lake areas from 1986/89 to 2000/03; a 79% increase from 2000/03 to 2020; and a 173% increase from 1986 to 2020. From 1986 to 2020, the most significant changes were a decrease in the average elevation and distance from glaciers and an increase in distance from the sea. In 2020, SSI lakes were predominantly coastal and ice-marginal, with an E and S orientations, flat surfaces, and a low declivity.

Geophysical investigation in sediment cores and its relationship with the governing sedimentary processes at Bransfield Basin, Antarctica.

This research aims to investigate sediment cores from a glaciomarine environment based on their petrophysical parameters to elucidate lithological and sedimentary issues, as well as to identify a geophysical signature based on their parameter's response. To achieve this objective, six marine sediment cores were collected in the Central Bransfield Basin - Antarctica, the lengths ranging from 1.5 to 5.2 meters in water depths ranging from 304 to 1463 meters. The cores were submitted to different analyses and values from density, magnetic susceptibility, electrical resistivity, p-wave velocity, total gamma radiation, silt, clay and sand contents, and mean grain size for each core location were considered. Four large lithologies were identified according to their geological and geophysical characteristics. The first group is subglacial deformation till (GC16); the second is massive diamicton (GC13 and GC12), the third group is composed of diamictons from the basin (AM10) and lower slope (GC09); the fourth lithological group is composed of siliceous mud from an upper slope location (GC06A). The characteristics recorded across Central Bransfield Basin (from South Shetlands Islands to Antarctic Peninsula) highlighted the relationship between the lithological content and associated depositional processes with the geophysical proprieties as density and magnetic susceptibility.

Fungal diversity in a sediment core from climate change impacted Boeckella Lake, Hope Bay, north-eastern Antarctic Peninsula assessed using metabarcoding.

We studied the fungal DNA present in a lake sediment core obtained from Trinity Peninsula, Hope Bay, north-eastern Antarctic Peninsula, using metabarcoding through high-throughput sequencing (HTS). Sequences obtained were assigned to 146 amplicon sequence variants (ASVs) primarily representing unknown fungi, followed by the phyla Ascomycota, Rozellomycota, Basidiomycota, Chytridiomycota and Mortierellomycota. The most abundant taxa were assigned to Fungal sp., Pseudeurotium hygrophilum, Rozellomycota sp. 1, Pseudeurotiaceae sp. 1 and Chytridiomycota sp. 1. The majority of the DNA reads, representing 40 ASVs, could only be assigned at higher taxonomic levels and may represent taxa not currently included in the sequence databases consulted and/or be previously undescribed fungi. Different sections of the core were characterized by high sequence diversity, richness and moderate ecological dominance indices. The assigned diversity was dominated by cosmopolitan cold-adapted fungi, including known saprotrophic, plant and animal pathogenic and symbiotic taxa. Despite the overall dominance of Ascomycota and Basidiomycota and psychrophilic Mortierellomycota, members of the cryptic phyla Rozellomycota and Chytridiomycota were also detected in abundance. As Boeckella Lake may cease to exist in approaching decades due the effects of local climatic changes, it also an important location for the study of the impacts of these changes on Antarctic microbial diversity.

Sedimentary evidence of glacial entrainment at Patriot Hills and Union Glacier moraines, Ellsworth Mountains, West Antarctica.

This work aims to analyze and compare the sedimentological data of Ellsworth Mountains, West Antarctica: Patriot/Independence Hills and Union Glacier, and how sedimentological data can be used to infer sediment entrainment. Particular attention was concentrated on morainic deposits. Remote sensing data was used in the identification of deposits and the ice flow; granulometric, morphoscopic, and geochemical analyses were applied to investigate the sedimentary origin and transport history. Sediment rich in Si Al, Fe, and Ca predominate in Independence Hills and Rossman Cove but Ca prevails in Elephant Head. CIA indicated low values, which depict low chemical weathering processes. X-ray diffraction reveals the presence of minerals that constitute the local rocks in the Union Glacier area, and from the unexposed basement rocks in Independence Hills. Principal Component Analysis and Cluster Analysis results suggest the sediment is related to the local rocks in the Union Glacier and distinct exotic sources in Independence Hills, associated with far-traveled sediment. It is also observed the influence of distinct processes of entrainment sediment on its granulometric and morphoscopic characteristics.

Green algae (Viridiplantae) in sediments from three lakes on Vega Island, Antarctica, assessed using DNA metabarcoding.

BACKGROUND: Vega Island is located off the eastern tip of the Antarctic Peninsula (Maritime Antarctica), in the Weddell Sea. In this study, we used metabarcoding to investigate green algal DNA sequence diversity present in sediments from three lakes on Vega Island (Esmeralda, Copépodo, and Pan Negro Lakes). METHODS AND RESULTS: Total DNA was extracted and the internal transcribed spacer 2 region of the nuclear ribosomal DNA was used as a DNA barcode for molecular identification. Green algae were represented by sequences representing 78 taxa belonging to Phylum Chlorophyta, of which 32% have not previously been recorded from Antarctica. Sediment from Pan Negro Lake generated the highest number of DNA reads (11,205), followed by Esmeralda (9085) and Copépodo (1595) Lakes. Esmeralda Lake was the richest in terms of number of taxa (59), with Copépodo and Pan Negro Lakes having 30 taxa each. Bray-Curtis dissimilarity among lakes was high (~ 0.80). The Order Chlamydomonadales (Chlorophyceae) gave the highest contribution in terms of numbers of taxa and DNA reads in all lakes. The most abundant taxon was Chlorococcum microstigmatum. CONCLUSIONS: The study confirms the utility of DNA metabarcoding in assessing potential green algal diversity in Antarctic lakes, generating new Antarctic records.

Diversity of fungal DNA in lake sediments on Vega Island, north-east Antarctic Peninsula assessed using DNA metabarcoding.

We assessed the diversity of fungal DNA present in sediments of three lakes on Vega Island, north-east Antarctic Peninsula using metabarcoding through high-throughput sequencing (HTS). A total of 640,902 fungal DNA reads were detected, which were assigned to 224 taxa of the phyla Ascomycota, Rozellomycota, Basidiomycota, Chytridiomycota and Mortierellomycota, in rank order of abundance. The most abundant genera were Pseudogymnoascus, Penicillium and Mortierella. However, a majority (423,508, 66%) of the reads, representing by 43 ASVs, could only be assigned at higher taxonomic levels and may represent taxa not currently included in the sequence databases used or be new or previously unreported taxa present in Antarctic lakes. The three lakes were characterized by high sequence diversity, richness, and moderate dominance indices. The ASVs were dominated by psychrotolerant and cosmopolitan cold-adapted Ascomycota, Basidiomycota and Mortierellomycota commonly reported in Antarctic environments. However, other taxa detected included unidentified members of Rozellomycota and Chytridiomycota species not previously reported in Antarctic lakes. The assigned diversity was composed mainly of taxa recognized as decomposers and pathogens of plants and invertebrates.

Fungi Present in Antarctic Deep-Sea Sediments Assessed Using DNA Metabarcoding.

We assessed fungal diversity in deep-sea sediments obtained from different depths in the Southern Ocean using the internal transcribed spacer 2 (ITS2) region of nuclear ribosomal DNA by metabarcoding through high-throughput sequencing (HTS). We detected 655,991 DNA reads representing 263 fungal amplicon sequence variants (ASVs), dominated by Ascomycota, Basidiomycota, Mortierellomycota, Mucoromycota, Chytridiomycota and Rozellomycota, confirming that deep-sea sediments can represent a hotspot of fungal diversity in Antarctica. The community diversity detected included 17 dominant fungal ASVs, 62 intermediate and 213 rare. The dominant fungi included taxa of Mortierella, Penicillium, Cladosporium, Pseudogymnoascus, Phaeosphaeria and Torula. Despite the extreme conditions of the Southern Ocean benthos, the total fungal community detected in these marine sediments displayed high indices of diversity and richness, and moderate dominance, which varied between the different depths sampled. The highest diversity indices were obtained in sediments from 550 m and 250 m depths. Only 49 ASVs (18.63%) were detected at all the depths sampled, while 16 ASVs were detected only in the deepest sediment sampled at 1463 m. Based on sequence identities, the fungal community included some globally distributed taxa, primarily recorded otherwise from terrestrial environments, suggesting transport from these to deep marine sediments. The assigned taxa included symbionts, decomposers and plant-, animal- and human-pathogenic fungi, suggesting that deep-sea sediments host a complex fungal diversity, although metabarcoding does not itself confirm that living or viable organisms are present.

Diversity, ecology, and bioprospecting of culturable fungi in lakes impacted by anthropogenic activities in Maritime Antarctica.

In this study, we accessed culturable fungal assemblages present in the sediments of three lakes potentially impacted anthropogenically in the Fildes Peninsula, King George Island, Antarctica and identified 63 taxa. Cladosporium sp. 2, Pseudeurotium hygrophilum, and Pseudogymnoascus verrucosus were recovered from the sampled sediments of all lakes. High concentrations of metals and the lowest fungal diversity indices were detected in the sediments of the Central Lake, which can be influenced by human activities due to their proximity to research stations to those of the other two lakes, which were far from the Antarctic stations. At least one type of biological activity was demonstrated by 40 fungal extracts. Among these, P. hygrophilum, P. verrucosus, Penicillium glabrum, and Penicillium solitum demonstrated strong trypanocidal, herbicidal, and antifungal activities. Our results suggest that an increase of the anthropogenic activities in the region might have affected the microbial diversity and composition. In addition, the fungal diversity in these lakes may be a useful model to study the effect of anthropogenic activities in Antarctica. We isolated a diverse group of fungal taxa from Antarctic lake sediments, which have the potential to produce novel compounds for the both the medical and agriculture sectors.

Diversity and bioprospecting of cultivable fungal assemblages in sediments of lakes in the Antarctic Peninsula.

We recovered 195 fungal isolates from the sediments of different lakes in the Antarctic Peninsula, which were screened to detect bioactive compounds. Forty-two taxa belonging to the phyla Ascomycota, Basidiomycota, and Mortierellomycota were identified. Thelebolus globosus, Antarctomyces psychrotrophicus, Pseudogymnoascus verrucosus, Vishniacozyma victoriae, and Phenoliferia sp. were found to be the most prevalent. The fungal assemblages showed high diversity and richness, but low dominance values. However, the diversity indices and fungal distribution ranged according to the different lake sediments. Sixty fungal extracts displayed at least one biological activity against the evaluated targets. Among them, Pseudogymnoascus destructans showed selective trypanocidal activity, Cladosporium sp. 1 and Trichoderma polysporum showed antifungal activity, and Pseudogymnoascus appendiculatus and Helotiales sp. showed high herbicidal activity. We detected a rich and diverse fungal community composed of cold cosmopolitan and psychrophilic endemic taxa recognized as decomposers, symbiotics, pathogens, and potential new species, in the sediments of Antarctic lakes. The dynamics and balance of this fungal community represents an interesting aquatic web model for further ecological and evolutionary studies under extreme conditions and potential climate changes in the regions. In addition, we detected fungal taxa and isolates able to produce bioactive compounds that may represent the source of prototype molecules for applications in medicine and agriculture.

Cultivable fungi present in deep-sea sediments of Antarctica: taxonomy, diversity, and bioprospecting of bioactive compounds.

We accessed the culturable mycobiota present in marine sediments at different depths in Antarctica Ocean. Acremonium fusidioides, Penicillium allii-sativi, Penicillium chrysogenum, Penicillium palitans, Penicillium solitum, and Pseudogymnoascus verrucosus were identified. Penicillium allii-sativi was the dominant species. At least one isolate of each species was capable to present antifungal, trypanocidal, leishmanicidal, antimalarial, nematocidal, or herbicidal activities. Penicillium produced extracts with strong trypanocidal and antimalarial activities, and the extracts of P. solitum and P. chrysogenum demonstrated strong antimalarial activities. Acremonium fusidioides and P. verrucosus displayed strong selective herbicidal properties. The 1H NMR signals for extracts of A. fusidioides, P. chrysogenum, and P. solitum indicated the presence of highly functionalized secondary metabolites, which may be responsible for the biological activities detected. In the deep marine Antarctic sediments, we detected fungal assemblages in which the Penicillium species were found to be dominant and demonstrated capabilities to survive and/or colonise that poly-extreme habitat. Penicillium being a polyextremophile Antarctic species, exhibited strong biological activities and the presence of aromatic compounds in its extracts may indicate that they are wild ancient strains with high genetic and biochemical potentials that enable them to produce bioactive compounds which can be researched in further studies and used in the chemotherapy of neglected tropical diseases as well as in agriculture.

Transtornos mentais e trabalho: o caso de um agente de visitação / Mental disorders and work: the case of an agent visits

O estabelecimento do nexo causal entre trabalho e distúrbio mental tem ocupado um lugar central nos debates teóricos e se configura como uma questão bastante polêmica, centro de controvérsias no campo de estudos da Saúde Mental e Trabalho. O presente artigo discute o caso de um trabalhador cujo processo de adoecimento parece estar relacionado à sua última experiência de trabalho. A construção deste caso foi inspirada no método biográfico de Louis Le Guillant (2006) e na Análise Psicossocial do Trabalho proposta por Lima (2002). Os dados empíricos foram coletados por meio de cinco entrevistas não-estruturadas, realizadas junto ao trabalhador. No decorrer do estudo, também foram analisados os laudos emitidos pelo serviço de perícia médica da instituição contratante. Ao final deste artigo, indicamos que as agressões sofridas no trabalho, a precariedade do suporte social para a resolução dos conflitos, a degradação da ação profissional e do sentido do trabalho, a ausência de reconhecimento e as escalas de folga incompatíveis com a preservação da vida social do trabalhador se configuram como elementos-chave para o entendimento do processo de adoecimento.

Establishing a causal relationship between work and mental illnesses has been at the center of theoretical debates and considered a rather polemic issue, being one of the controversies in the field of mental health and work. This article discusses the case of a worker whose process of getting sick seems to be connected to his last work experience. The groundwork of this case was the Biographic Method of Louis Guillant (2006), and the analysis of work-related psychosocial factors proposed by Lima (2002). The data were found empirically by means of carrying out five unstructured interviews with the worker. Over the studying period, the report issued by the medical inspection service of our client was also analyzed. In the end of this article, we indicate the aggressions and aggravations suffered by the worker such as an insufficient social support for solving conflicts, the degradation of the professional activity, and as well of the meaning of work itself, the lack of acknowledgment, and also work-rest shift schedules unfitted for allowing the worker to preserve his social life are the main factors that proved to be the key-elements for understanding such sickening process.