Solid and liquid fractions of hydrothermally pretreated sugarcane bagasse (SCB) were simultaneously used as substrate of a novel continuous compartmentalized reactor. The effect of four (56, 42, 28, and 14 h) hydraulic retention time (HRT) and three (0.5, 3.0, and 9.0 g L-1) chemical oxygen demand (COD) levels were evaluated on hydrogen (H2) and organic acids production. Higher H2 production and yield (686 mL and 1.63 mol mol-1 carbohydrate, respectively) were obtained under an HRT of 28 h, probably due to the Clostridium and Thermoanaerobacterium metabolisms, which accounted for almost 60% of the microbial relative abundance. Under lower and higher HRT (14 and 56 h, respectively) lactic acid prevailed without hydrogen production. Other value-added chemicals such as citric, valeric and caproic acids were also obtained according to the HRT. From the functional point of view, enzymes from the glycoside hydrolases group (GHs) potentially performed important roles in the lignocellulosic biomass bioconversion. SCB (SCB reactor 56, (56 42 1 h (HRT 0.5, 05 0 5 (0.5 30 3 3.0 90 9 9. L1 L L-1 COD (COD H (H2 686 (68 163 63 1.6 mol1 mol- carbohydrate respectively 2 metabolisms 60 abundance (1 valueadded value added citric view GHs (GHs bioconversion (5 4 0.5 (0. 3. L- (H 68 (6 16 6 1. ( 0. (0

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 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 Industrial sectors are searching for new compounds to improve the preservation of food and blood, human tissues, and fuels used at low temperatures. Antarctic microorganisms have mechanisms to overcome injuries caused by low temperatures, making them sources of compounds with antifreeze activity. However, it is mandatory that such compounds do not pose a risk to human health. The present study evaluated the potential of Antarctic bacteria to resist freezing, produce virulence factors, their tolerance to physiological pHs/temperature and resistance to antibiotics. Sixty-five isolates were tested for antifreeze compound production, among which, 31 grew after the test. Of these, 3 strains of Arthrobacter sp. (356, 358 and 443), one Psychromonas arctica (ESH238) and one unidentified strain (363) showed positive results for hemolytic activity. Psychrobacter sp. 456 showed proteinase activity. None of the isolates showed resistance to the antibiotics. All isolates were able to grow in one of the three pHs (4, 7 and 8) and/or temperature (36, 38 and 40 ºC). Antarctic bacterial present potential for the production of antifreeze compounds and may be considered safe in industrial processes. The characterization of the genes responsible for virulence factors should be carried out to reinforce the potential applicability of such bacteria.

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.

Indigenous bacteria isolated from a crude oil sample from a deep water reservoir in the Pampo Sul Oilfield (Campos Basin-RJ, Brazil) were previously classified as strains of B. pumilus. However, their enzymatic activities with fluorogenic probes and rates of petroleum biodegradation were completely different. Some of the bacteria depleted n-alkanes, whereas others did not. Aromatic compounds reported to be recalcitrant were also biodegraded by some of these Bacillus strains, revealing their outstanding ability to deplete petroleum. Further classification using matrixassisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) followed by statistical analysis revealed that these strains could be clustered into three different groups, consistent with their enzymatic activity evaluation. A more accurate phylogenetic analysis using gyrB gene sequences confirmed the MALDI-TOF MS classification of three groups of strains and identified them as Bacillus safensis, B. cereus and B. thuringiensis.