"Antarctic yeasts as a source of L-asparaginase: Characterization of a glutaminase-activity free L-asparaginase from psychrotolerant yeast Leucosporidium scottii L115"

"Microorganisms from extreme environments, such as the Antarctic ecosystems, have a great potential to produce enzymes with novel characteristics. Within this context, L-asparaginase (ASNase) obtained from yeast species has been poorly studied. In this study, yeasts isolated from samples collected at Admiralty Bay (King George Island, Antarctica) were tested to produce ASNase. From an initial screening of 40 strains, belonging to 13 different species, Leucosporidium scottii L115 produced an ASNase activity (LsASNase activity: 6.24 U g-1 of dry cell weight) with the lowest glutaminase activity. The LsASNase was purified 227-fold, with a specific activity of 137.01 U mg-1 at 37 ◦C, without glutaminase activity. Moreover, the maximum enzyme activity was observed at pH 7.5 and at a temperature of 55 ◦C. The enzyme is a multimer of 462 kDa, presenting a single band of 53 kDa molecular mass in reduced conditions; after PGNase F treatment, a single band of 45 kDa was observed. The enzymatic kinetic evaluation revealed an allosteric regulation of the enzyme and the kinetic parameters were determined at 37 ◦C, pH 7.0 as substrate affinity constant, K0.5 = 233 μM, kcat = 54.7 s − 1 and Hill coefficient, nH = 1.52, demonstrating positive cooperativity by the enzyme and the substrate. This is the first study to report L. scottii as a source of glutaminase-activity free L-asparaginase, an acute lymphoblastic leukemia drug feature suitable for the treatment of asparagine synthetase negative cancer cells.

Implémentation d’une ligue académique de médecine interne générale à l’UNIGE : un projet- action

Introduction : Une ‘ligue académique’ de médecine interne générale (LAMIG) est une association d’étudiants en médecine humaine comportant des activités théoriques et pratiques autour de la médecine générale. La réalisation autonome d’un projet d’équipe ainsi que l’exposition précoce à des activités pratiques en milieu clinique visent à renforcer la motivation et l’autonomie des étudiants en plus de contribuer au développement de l’aisance en milieu clinique et de l’apprentissage du travail en équipe. Méthode : Selon un modèle de ‘mise en oeuvre d’un projet en cinq étapes’ (préparation du projet, définition, planification, réalisation et clôture ou interruption), un groupe d’étudiants en bachelor de médecine humaine (2-3BA) développe une ligue. L’évaluation de l’intervention repose sur deux questionnaires ainsi que sur l’observation de l’évolution du projet. Résultats : Six étudiants ont participé au développement de la ligue. Dix sur seize activités prévues ont pu être réalisées. L’association a dû être interrompue temporairement en raison de la situation sanitaire (COVID19). Le résultat des questionnaires et l’engagement des étudiants témoignent d’un impact positif sur les aspects recherchés initialement. Les membres ont donné spontanément suite au projet. L’association compte à ce jour sept nouveaux étudiants et prend la structure d’une association estudiantine à part entière. Conclusion : L’expérience réalisée à travers ce projet-action ouvre les portes sur un programme longitudinal extra-curriculaire de type ‘ligue académique’ comme moyen de renforcer l’apprentissage et l’expérience académique des étudiants en médecine humaine. Des études supplémentaires devraient investiguer davantage l’impact d’une telle intervention sur les critères ci-étudiés ainsi que sur d’autres potentiels bénéfices

Liquid-liquid Extraction Of Lipase Produced By Psychrotrophic Yeast Leucosporidium Scottii L117 Using Aqueous Two-phase Systems

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Aqueous two-phase systems (ATPS) have been used in biomolecules separation and as an efficient alternative to traditional purification systems for lipases extraction. Here, we investigated the partitioning and recovery of lipase derived from Leucosporidium scottii L117 using ATPS and aqueous two-phase micellar systems (ATPMS). Thus, we evaluated three ATPS: (i) polyethylene glycol (PEG)/phosphate salts and (ii) PEG/polyacrylic acid (NaPA) in different molecular weights (1500, 4000 and 8000 g/mol). (iii) Triton X-114 (TX-114)/McIlvaine buffer pH 7.0 in different conditions (2.0% (w/w) of TX-114 at 25.0 and 28.0 degrees C). The PEG/phosphate and PEG/NaPA systems resulted in a great loss of enzymatic activity; thus these systems do not represent viable alternatives for these lipase extraction. The micellar systems yielded the best results for lipase extraction with enzyme activity balances ranging between 84.7% and 113.05%. After optimizing the micellar system by experimental design of the partition coefficient of lipase increased by 10.3-fold (0.75-7.76). Lipase preferentially partitioned into the micelle-rich phase with K-Lip = 7.76, % RECBot = 93.85% and PF = 1.2 at 25.03 degrees C, 5.1 pH and 10.38% TX-114 and K-Lip, = 4.77, % RECBot = 73.53% and PF = 1.97 at 28.00 degrees C, 4.5 pH and 8.0% TX-114, indicating that the ATPMS represents an alternative to purification/extraction of lipase L scottii L117. A crude lipase extract was also evaluated to define the optimum pH and temperature. Lipase reached optimal activity at 40 degrees C, and remained stable in pH values ranging from pH 3.0 to 8.0 and temperatures from 20.0 to 45.0 degrees C, with relative residual lipase activity above 80% after 30 min of incubation. (C) 2015 Elsevier B.V. All rights reserved.156215225Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [2010/08352-5, 2010/17033-0, 2013/19486-0

The Production of Ligninolytic Enzymes by Marine-Derived Basidiomycetes and Their Biotechnological Potential in the Biodegradation of Recalcitrant Pollutants and the Treatment of Textile Effluents

Filamentous fungi derived from marine environments are well known as a potential genetic resource for various biotechnological applications. Although terrestrial fungi have been reported to be highly efficient in the remediation of xenobiotic pollutants, fungi isolated from the marine environment may possess biological advantages over terrestrial fungi because of their adaptations to high salinity and pH extremes. The present study describes the production of ligninolytic enzymes under saline and non-saline conditions and the decolorization of Remazol Brilliant Blue R (RBBR) dye by three basidiomycetes recovered from marine sponges (Tinctoporellus sp. CBMAI 1061, Marasmiellus sp. CBMAI 1062, and Peniophora sp. CBMAI 1063). Ligninolytic enzymes were primarily produced by these fungi in a salt-free malt extract and malt extract formulated with artificial seawater (saline condition). CuSO4 and wheat bran were the best inducers of lignin peroxidase and manganese peroxidase activity. RBBR was decolorized up to 100% by the three fungi, and Tinctoporellus sp. CBMAI 1061 was the most efficient. Our results revealed the biotechnological potential of marine-derived basidiomycetes for dye decolorization and the treatment of colored effluent as well as for the degradation of other organopollutants by ligninolytic enzymes in non-saline and saline conditions that resemble the marine environment.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Algae's Sulfated Polysaccharides Modifications: Potential Use Of Microbial Enzymes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Marine algae are valuable sources of structurally diverse bioactive compounds, among them, the group of sulfated polysaccharides (SPs). As an example of SPs, it could be cited the fucoidans in brown algae, carrageenans in red algae and ulvans in green algae. Since the past decades, SPs have been extracted from algae and evaluated in respect to their beneficial biological activities such as anti-inflammatory, antioxidative, antimicrobial, anticoagulant, antithrombotic, immunological and anticancer. This review deals with the presentation of natively bioactive SPs structural features in addition to already employed approaches of SPs structure modifications, such as chemical and physical methods. Moreover, this article presents the advantages and the importance of using enzymatic methods during SPs modification, and particularly, the use of microorganisms as enzymes sources. Enzymes such as hydrolases/glycosidases (e.g. fucoidanase, fucosidase, agarase and carrageenase), lyases, sulfotransferases and sulfatases could be used for this purpose. It has been shown that more studies are necessary to obtain/identify opportunities to create novel, or to intensify, SPs biological properties. Considering the advantages in the use of microbial enzymes in biotransformation processes, studies related to the modification of SPs by microorganisms should be stimulated. (C) 2016 Elsevier Ltd. All rights reserved.518989998CNPq [552620/2011-4]FAPESP [2013/19486-0]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Immobilization of marine fungi on silica gel, silica xerogel and chitosan for biocatalytic reduction of ketones

The scanning electron microscopy (SEM) analysis showed that whole living hyphal of marine fungi Aspergillus sclerotiorum CBMAI 849 and Penicillium citrinum CBMAI 1186 were immobilized on support matrices of silica gel, silica xerogel and/or chitosan. P. citrinum immobilized on chitosan catalyzed the quantitative reduction of 1-(4-methoxyphenyl)-ethanone (1) to the enantiomer (S)-1-(4-methoxyphenyl)-ethanol (3b), with excellent enantioselectivity (ee > 99%, yield = 95%). Interestingly, ketone 1 was reduced with moderate selectivity and conversion to alcohol 3b (ee = 69%, c 40%) by the free mycelium of P. citrinum. This free mycelium of P. citrinum catalyzed the production of the (R)-alcohol 3a, the antipode of the alcohol produced by the immobilized cells. P. citrinum immobilized on chitosan also catalyzed the bioreduction of 2-chloro-1-phenylethanone (2) to 2-chloro-1-phenylethanol (4a,b), but in this case without optical selectivity. These results showed that biocatalytic reduction of ketones by immobilization hyphal of marine fungi depends on the xenobiotic substrate and the support matrix used. (c) 2012 Elsevier B.V. All rights reserved.10th International Symposium on Biocatalysis and Biotransformations (BIOTRANS)8416016

Yeasts From Macroalgae And Lichens That Inhabit The South Shetland Islands, Antarctica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Antarctic terrestrial ecosystems are largely dominated by lichens, while shallow coastal environments are mainly covered by macroalgae. The aim of this study was to isolate and to evaluate the diversity of yeasts in different species of macroalgae and lichens collected in South Shetland Islands, Antarctica. A total of 405 yeasts were recovered (205 from macroalgae and 200 from lichens). The yeast community from macroalgae was most diversity than the yeast community from lichen. The dominance index was similar for both substrates. A total of 24 taxa from macroalgae and 18 from lichens were identified, and only 5 were common to both substrates. Metschnikowia australis, Mrakia sp., Rhodotorula glacialis and Glaciozyma litorale were the most abundant yeasts in macroalgae and Cryptococcus victoriae, Rhodotorula laryngis, Rhodotorula arctica, Trichosporon sp. 1 and Mrakia sp. were the most abundant in lichens. Based on molecular and phylogenetic analyses, four yeast from macroalgae and six from lichens were considered potential new species. This is the first study to report the yeast communities from the Antarctic macroalgae Himantothallus grandifolius and lichen Ramalina terebrata. Results suggest that Antarctic phyco and lichensphere represent a huge substrate for cold-adapted yeasts and enhanced the knowledge of the microbiota from extreme environments.85874885Brazilian Antarctic Program (PROANTAR)INCT CRIOSFERACoordination for Higher Level Graduate Improvement (CAPES/Brazil)State of Sao Paulo Research Foundation (FAPESP/Brazil) [2010/17033-0, 2013/19486-0]CAPESFAPESP [2010/08352-5]National Council for Scientific and Technological Development (CNPq) [304103/2013-6]Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Bioconversion of Iodoacetophenones by Marine Fungi

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Nine marine fungi (Aspergillus sclerotiorum CBMAI 849, Aspergillus sydowii Ce19, Beauveria felina CBMAI 738, Mucor racemosus CBMAI 847, Penicillium citrinum CBMAI 1186, Penicillium miczynskii Ce16, P. miczynskii Gc5, Penicillium oxalicum CBMAI 1185, and Trichoderma sp. Gc1) catalyzed the asymmetric bioconversion of iodoacetophenones 1-3 to corresponding iodophenylethanols 6-8. All the marine fungi produced exclusively (S)-ortho-iodophenylethanol 6 and (S)-meta-iodophenylethanol 7 in accordance to the Prelog rule. B. felina CBMAI 738, P. miczynskii Gc5, P. oxalicum CBMAI 1185, and Trichoderma sp. Gc1 produced (R)-para-iodophenylethanol 8 as product anti-Prelog. The bioconversion of para-iodoacetophenone 3 with whole cells of P. oxalicum CBMAI 1185 showed competitive reduction-oxidation reactions.144396401Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade de São Paulo (USP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Bioconversion of Iodoacetophenones by Marine Fungi

Nine marine fungi (Aspergillus sclerotiorum CBMAI 849, Aspergillus sydowii Ce19, Beauveria felina CBMAI 738, Mucor racemosus CBMAI 847, Penicillium citrinum CBMAI 1186, Penicillium miczynskii Ce16, P. miczynskii Gc5, Penicillium oxalicum CBMAI 1185, and Trichoderma sp. Gc1) catalyzed the asymmetric bioconversion of iodoacetophenones 1-3 to corresponding iodophenylethanols 6-8. All the marine fungi produced exclusively (S)-ortho-iodophenylethanol 6 and (S)-meta-iodophenylethanol 7 in accordance to the Prelog rule. B. felina CBMAI 738, P. miczynskii Gc5, P. oxalicum CBMAI 1185, and Trichoderma sp. Gc1 produced (R)-para-iodophenylethanol 8 as product anti-Prelog. The bioconversion of para-iodoacetophenone 3 with whole cells of P. oxalicum CBMAI 1185 showed competitive reduction-oxidation reactions.Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)USP-ReitoriaUSPReitori

Bioconversion of iodoacetophenones by marine fungi

Nine marine fungi (Aspergillus sclerotiorum CBMAI 849, Aspergillus sydowii Ce19, Beauveria felina CBMAI 738, Mucor racemosus CBMAI 847, Penicillium citrinum CBMAI 1186, Penicillium miczynskii Ce16, P. miczynskii Gc5, Penicillium oxalicum CBMAI 1185, and Trichoderma sp. Gc1) catalyzed the asymmetric bioconversion of iodoacetophenones 1–3 to corresponding iodophenylethanols 6–8. All the marine fungi produced exclusively (S)-ortho-iodophenylethanol 6 and (S)-meta-iodophenylethanol 7 in accordance to the Prelog rule. B. felina CBMAI 738, P. miczynskii Gc5, P. oxalicum CBMAI 1185, and Trichoderma sp. Gc1 produced (R)-para-iodophenylethanol 8 as product anti-Prelog. The bioconversion of para-iodoacetophenone 3 with whole cells of P. oxalicum CBMAI 1185 showed competitive reduction–oxidation reactions144396401CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPUSP-Reitori