Repositório Institucional - Unifesp :: Navegando por Palavras-chave "Fungi"

Navegando por Palavras-chave "Fungi"

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Acesso aberto (Open Access)
Análises de glicoesfingolipídeos em diferentes espécies do fungo patogênico do gênero Aspergillus
(Universidade Federal de São Paulo (UNIFESP), 2018-06-28) Rodrigues, Karolina Marques [UNIFESP]; Takahashi, Helio Kiyoshi [UNIFESP]; http://lattes.cnpq.br/8090231917635170; Universidade Federal de São Paulo (UNIFESP)
incidence of serious fungal infections has increased in the last decade, mainly due to the increase in the number of immunocompromised patients, representing a serious cause of morbidity and mortality in this population. Recent works show that fungi are vulnerable to inhibitors of sphingolipid biosynthesis, which led us to study the structures of fungal glycosphingolipids, in order to obtain relevant information on the biosynthesis and functional roles of these molecules and to propose new potential targets for antifungal treatment. Glycosylinositol phosphorilceramides (GIPCs), inositolphosphoryl ceramides (IPCs), and monohexosyl ceramides (CMHs) from A. fumigatus, A. flavus, A. niger and A. nidulans, filamentous fungi causing aspergillosis, were extracted, purified and characterized using methods chromatography, biochemistry and mass spectrometry. By mass spectrometry using electrospray ionization (EISMS) in positive mode, two major peaks corresponding to CMHs of 754 m/z and 756 m/z were identified for all species analyzed. By collisioninduced dissociation (CID), m/z fragments of m/z: 736, 574, 556 and 276 were identified for CMH 754 m/z. Similarly for CMH m/z 756 fragments of m/z 738, 576, 558 and 276. The fragmentation pattern for both CMHs corresponds respectively to [M+H1H2O]+, [M+H1H2OHex]+, [M+H2H2OHex]+, [M+H2H2Oacyl]+, the fragments associated with ceramidecontaining CMH, with structures not described in mammalian CMH, d19:2/h18:1 and d19:2/18:0, respectively. Glucosylceramide and galactosylceramide were characterized by high resolution thin layer chromatography (HPTLC). It was possible to identify 2 different species of IPCs [M+H]+, 926 m/z, and 954 m/z, presenting 282 m/z and 310 m/z fragments for sphingosine t18:0 and t20:0, respectively. The presence of inositol was confirmed using 241 m/z precursor ion mass spectrometry, referring to the inositol phosphate group of these structures. For the characterization of the GIPCs in the different Aspergillus species, we used collision induced dissociation (DIC) in tandem MS with eletrotron ionization (ESI), in positive mode [M+H]+. In this way we were able to detect the 1088 m/z and 1116 m/z ions corresponding to GIPCs with 1 hexose; 1250 m/z and 1278 m/z, GIPCs with 2 hexoses; 1412 m/z and 1440 m/z, corresponding to GIPCs containing 3 hexoses. The GIPCs present A. fumigatus, A. flavus and A. niger were derived from the IPC 926 m/z (containing ceramide 666 m/z) and the IPC 954 m/z (containing ceramid 694 m/z), on the other hand, the A. nidulans GIPCs are derived only from the IPC 926 m/z. The presence of galactofuranose residues in GIPCs was confirmed using the monoclonal antibody MEST1 which recognizes terminal residues of galactofuranose. By immunostaining the HPTLC plates with MEST1 the A. fumigatus, A. flavus and A. niger GIPCs, which had a component recognized by mAb MEST1, have the same chromatographic migration as GIPC called Pb1 of Paracoccidioides brasiliensis. As for A. nidulans, only small reactivity with mAb MEST1 was detected. These results indicate that in the four species studied, both CMHs, IPCs and GIPCs have structures not expressed in mammals, indicating that these molecules as well as the specific enzymes involved in the metabolism of these sphingolipids can be considered as targets for antifungal treatment .
Embargo
Avaliação da atividade celulolítica e prospecção de metabólitos secundários em fungos filamentosos isolados em associação com cupins (Insecta: Blattodea: Isoptera)
(Universidade Federal de São Paulo, 2022-12-20) Silva, Giordanno Di Gioia [UNIFESP]; Okamoto, Débora Noma [UNIFESP]; Medeiros, Lívia Soman de [UNIFESP]; http://lattes.cnpq.br/7404733691134037; http://lattes.cnpq.br/5115280107160951; http://lattes.cnpq.br/6845014488756820
Os cupins são insetos capazes de degradar a celulose, capacidade proveniente de interações simbióticas com micro-organismos produtores de celulases, além da produção endógena dos térmitas. A espécie Anoplotermes pacificus ocorre na Mata Atlântica e constrói seus ninhos em meio à serrapilheira. Sua alimentação é composta por celulose em estágios avançados de decomposição presente no solo. A celulose é um dos principais constituintes da parede celular de vegetais e na natureza sua decomposição ocorre principalmente pela ação de micro-organismos, especialmente por bactérias e fungos. Além de importantes decompositores, os fungos também são amplamente estudados por conta de seus metabólitos secundários que podem ser de interesse farmacêutico. A associação de cupins com fungos pode ser importante não apenas para fins nutricionais, como também para fins de defesa contra patógenos. Uma forma de se investigar esse tipo de associação é pela análise dos metabólitos produzidos por esses fungos, entretanto, as formas tradicionais de cultivo em laboratório ocorrem com os micro-organismos de maneira isolada. Nos ambientes naturais os micro-organismos não se encontram isolados, de forma que ao serem cultivados dessa maneira é esperado que deixem de produzir metabólitos relacionados aos diferentes tipos de interações que ocorreriam no meio natural. Com isso, o crescimento combinado de dois ou mais micro-organismos se apresenta como uma forma de mimetizar em laboratório algumas das interações que ocorrem na natureza e promover a produção de metabólitos secundários. Diante do exposto, este trabalho teve como objetivo investigar a associação cupins-fungo na espécie A. pacificus. Isso se deu pela avaliação da atividade celulolítica dos fungos através do ensaio da Unidade de Papel de Filtro (FPase) e pela investigação das induções metabólicas, decorrentes das interações microbianas promovidas por co-culturas, através de dados de CLAE-DAD. Os resultados obtidos indicam atividade celulolítica em fungos isolados a partir do trato intestinal do cupim e indução de aumento da produção de determinados metabólitos em decorrência das interações microbianas em algumas co-culturas. O presente trabalho contribuiu para ampliação do conhecimento acerca das interações entre A. pacificus e sua microbiota fúngica associada, com destaque para a possibilidade de associações nutricionais e defensivas.
Acesso aberto (Open Access)
Epidemiologia das doenças fúngicas invasivas em pacientes oncológicos pediátricos de um centro de referência
(Universidade Federal de São Paulo (UNIFESP), 2018-10-25) Marques, Leticia Maria Acioli [UNIFESP]; Fram, Dayana Souza [UNIFESP]; http://lattes.cnpq.br/8357646821341086; http://lattes.cnpq.br/1576805942427220; Universidade Federal de São Paulo (UNIFESP)
Objective: Analyze the epidemiology and incidence of invasive fungal diseases in oncological pediatric patients. Identify associated factors, analyze the seasonality, sites affected and outcome of these episodes. Methods: Retrospective cohort study from January 2011 to December 2016 developed in a reference hospital in pediatric oncology. We included all episodes of probable or proven invasive fungal disease, according to European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy Infectious Diseases Mycoses Study Group definitions, that occurred in cancer patients, submitted or not to stem cell hematopoietic cells transplantation, from 0 to 18 years old and followed at the institution during the study period. Demographic and clinical data were collected, the infections were classified as caused by yeast or filamentous fungi. Descriptive analysis was performed on absolute frequency (n) and relative frequency (%) and for analysis of the association between the two groups of agents causing the infections, p <0.05 was used for statistical significance. Results: were identified 103 episodes of invasive fungal disease in 94 patients. The mean age was 8.6 years, 60.6% (57/94) were males and 52.1% had (49/94) solid tumors as underlying disease. Among proven invasive fungal diseases, 77.3% (68/88) were caused by yeast and 22.7% (20/88) by mold. The overall incidence of fungal invasive disease in this population was 5.6 per thousand patients in treatment / year, 3.72 caused by yeast and 1.92 caused by mold. The most identified agents were Candida parapsilosis in the bloodstream (p <0.0001) and Fusarium solani affecting cutaneous tissue (p 0.003). The occurrence of invasive fungal disease occurred during spring was significant (p 0.012). Mortality in 30 days by yeasts was 29% and 21% caused by mold. Conclusion: The overall incidence of invasive fungal diseases was 5.6 / 1000 patients undergoing treatment year. A higher incidence of yeast was identified in patients with solid tumors. The main agent identified was C. parapsilosis in the bloodstream. There was higher in 30day mortality for DFI caused by yeast.
Acesso aberto (Open Access)
Estudo da micobiota em conjuntiva sadia de diabéticos, residentes na área urbana da cidade de São Paulo - Brasil
(Conselho Brasileiro de Oftalmologia, 2006-02-01) Andrade, Alfredo José Muniz de [UNIFESP]; Hofling-Lima, Ana Luisa [UNIFESP]; Yu, Maria Cecília Zorat [UNIFESP]; Godoy, Patricio [UNIFESP]; Gompertz, Olga Fischman [UNIFESP]; Bonfim, Sabrina de Souza [UNIFESP]; Andrade, Francisco Eudes Muniz de; Universidade Federal de São Paulo (UNIFESP); Universidade Federal de Pernambuco
PURPOSE: To determine the mycobiota of the healthy conjunctiva in diabetic individuals, according to diabetes type, age, sex, disease time, type of treatment, and stage of diabetic retinopathy of the individuals. To identify the anemophilus mycobiota in the sampling rooms. METHODS: A cross-sectional study was carried out on 803 diabetics who reside in the urban area of São Paulo-SP/Brazil. Sabouraud's dextrose agar culture with chloramphenicol was used for primoisolation, and the key of De Hoog was used to identify filamentous fungi. RESULTS: Of the evaluated diabetics, 6.6% (53/803) presented type 1 diabetes and 93.4% (750/803) type 2. The positive cultures for fungi in the conjunctiva of diabetics was 4.2% (34/803), with 1.9% (1/53) in type 1 diabetics and 4.4% (33/740) in type 2 diabetics (p=0.720). With respect to the presence or not of isolated fungi, there was no statistically significant association regarding age (p=0.575), sex (p=0.517), disease time (p=0.633), type of treatment (p=0.422), and diabetic retinopathy stage (p=0.655) of the tested individuals. The identified fungi were all filamentous: Aspergillus spp. represented 59.5% (25/42) of isolations and 47.6% (20/42) of isolated species were Aspergillus niger. Growth of anemophilus fungi occurred in the air of the room and coincidences were observed between the isolated species from the air and those from the conjunctiva. CONCLUSIONS: Presence of mycobiota in healthy conjunctivas of diabetics was identified, with no significant association between the greater number of positive fungi isolations and the type of diabetes, age, sex, disease type, type of treatment, and stage of diabetic retinopathy. In the collection rooms, anemophilus mycobiota was identified.
Somente Metadadados
Estudo experimental da eficácia da sulfadiazina de prata a 1
(Universidade Federal de São Paulo (UNIFESP), 1993) Sousa, Luciene Barbosa de [UNIFESP]; Scarpi, Marinho [UNIFESP]
Acesso aberto (Open Access)
Explorando as interações entre cupins e fungos e suas aplicações
(Universidade Federal de São Paulo, 2024-09-06) Saiz, Mariana Carolina Almeida [UNIFESP]; Santos, Fabiana Elaine Casarin dos [UNIFESP]; http://lattes.cnpq.br/5047065840855896; https://lattes.cnpq.br/3558546963858638
Termites are eusocial insects belonging to the infraorder Isoptera and are found in temperate and tropical regions of the planet. Due to their presence in various environments, termites engage in numerous interspecific ecological relationships and processes. For example, interactions between termites and fungi are common, as termite nests are rich in organic matter and moisture, creating a favorable environment for fungal growth. Research on this relationship has been conducted since the 1930s, and representatives from all classes of Fungi have been found associated with termites. This study aims to provide a comprehensive overview of the interactions between termites and fungi, as well as their implications, presented in two chapters. In Chapter I, a literature review was conducted on the main topics related to termite-fungi interactions. Data collection was carried out through searches in databases such as SciELO, Scopus, ResearchGate, and Web of Science. The review was structured into three main sections, each dedicated to a specific type of interaction. In each section, the implications of these relationships were also discussed when applicable. The study of termite-fungi interactions reveals the importance of these relationships, encompassing ecological, biological, and economic aspects. Chapter II presents an experimental study conducted with the native Brazilian termite species Nasutitermes corniger, a termite found in Central and South America. This species is one of the most prominent within its genus, both for its abundance and for being a major pest in agricultural and urban environments. Recent studies from this research group have shown that some species of fungi present in termite nests can be attractive, increasing the feeding behavior of these insects. Thus, this work tested the feasibility of fungi isolated from termite nests as phagostimulants for pest species. The fungus selected for the tests was a Penicillium species isolated from nests of Anoplotermes pacificus. The bioassays consisted of two-minute recordings, during which ten termites were observed in Petri dishes interacting with filter paper impregnated with either the treatment or the control. To determine whether the resource was attractive, the maximum number of individuals present on the resource throughout the trial (aggregation) and alarm occurrences were recorded. No alarm behavior was observed during the study period, suggesting a positive scenario. For aggregation, the null model was chosen to explain the variation in the data, indicating no significant effect of the treatments compared to the controls. Although the data did not show statistical differences, the graphs suggest a higher trend toward aggregation in the M50 treatment. Therefore, future studies with more repetitions and higher concentrations will be conducted to verify if this results in an increase in signal detection.
Acesso aberto (Open Access)
Fungal diversity in deep-sea sediments associated with asphalt seeps at the Sao Paulo Plateau
(Pergamon-Elsevier Science Ltd, 2017) Nagano, Yuriko; Miura, Toshiko; Nishi, Shinro; Lima, Andre O.; Nakayama, Cristina [UNIFESP]; Pellizari, Vivian H.; Fujikura, Katsunori
We investigated the fungal diversity in a total of 20 deep-sea sediment samples (of which 14 samples were associated with natural asphalt seeps and 6 samples were not associated) collected from two different sites at the Sao Paulo Plateau off Brazil by Ion Torrent PGM targeting ITS region of ribosomal RNA. Our results suggest that diverse fungi (113 operational taxonomic units (OTUs) based on clustering at 97% sequence similarity assigned into 9 classes and 31 genus) are present in deep-sea sediment samples collected at the Sao Paulo Plateau, dominated by Ascomycota (74.3%), followed by Basidiomycota (11.5%), unidentified fungi (7.1%), and sequences with no affiliation to any organisms in the public database (7.1%). However, it was revealed that only three species, namely Penicillium sp., Cadophora malorum and Rhodosporidiwn diobovatum, were dominant, with the majority of OTUs remaining a minor community. Unexpectedly, there was no significant difference in major fungal community structure between the asphalt seep and non-asphalt seep sites, despite the presence of mass hydrocarbon deposits and the high amount of macro organisms surrounding the asphalt seeps. However, there were some differences in the minor fungal communities, with possible asphalt degrading fungi present specifically in the asphalt seep sites. In contrast, some differences were found between the two different sampling sites. Classification of OTUs revealed that only 47 (41.6%) fungal OTUs exhibited >97% sequence similarity, in comparison with pre-existing ITS sequences in public databases, indicating that a majority of deep-sea inhabiting fungal taxa still remain undescribed. Although our knowledge on fungi and their role in deep-sea environments is still limited and scarce, this study increases our understanding of fungal diversity and community structure in deep-sea environments.
Acesso aberto (Open Access)
Identification of fungi species in the onychomycosis of institutionalized elderly
(Sociedade Brasileira de Dermatologia, 2013-06-01) Vasconcellos, Cidia; Pereira, Carolina Queiroz Moreira; Souza, Marta Cristina; Pelegrini, Andrea; Freitas, Roseli Santos; Takahashi, Juliana Possato; Universidade de São Paulo (USP); Institute of Medical Assistance to the State Public Server; University of the City of São Paulo; Universidade Federal de São Paulo (UNIFESP); Universidade Estadual Paulista (UNESP)
BACKGROUND: Superficial fungal infections are caused by dermatophytes, yeasts or filamentous fungi. They are correlated to the etiologic agent, the level of integrity of the host immune response, the site of the lesion and also the injured tissue. OBJECTIVE: The purpose of this study is to isolate and to identify onychomycosis agents in institutionalized elderly (60 years old +). METHODS: The identification of the fungi relied upon the combined results of mycological examination, culture isolation and micro cultures observation under light microscopy from nail and interdigital scales, which were collected from 35 elderly with a clinical suspicion of onychomycosis and a control group (9 elderly with healthy interdigital space and nails). Both groups were institutionalized in two nursing homes in Sao Bernardo do Campo, SP, Brazil. RESULTS: The nail scrapings showed 51.40% positivity. Of these, dermatophytes were found in 44.40% isolates, 27.78% identified as Trichophyton rubrum and 5.56% each as Trichophyton tonsurans, Trichophyton mentagrophytes and Microsporum gypseum. The second more conspicuous group showed 38.89% yeasts: 16.67% Candida guilliermondii, 11.11% Candida parapsilosis, 5.56% Candida glabrata, and 5.56% Trichosporon asahii. A third group displayed 16.70% filamentous fungi, like Fusarium sp, Aspergillus sp and Neoscytalidium sp (5.56% each). The interdigital scrapings presented a positivity rate of 14.29%. The agents were coincident with the fungi that caused the onychomycosis. In the control group, Candida guilliermondii was found at interdigital space in one person. CONCLUSION: Employing a combination of those identification methods, we found no difference between the etiology of the institutionalized elderly onychomycosis from that reported in the literature for the general population.
Acesso aberto (Open Access)
Microbial keratitis in the elderly: a 32-year review
(Conselho Brasileiro de Oftalmologia, 2010-08-01) Passos, Renato Magalhães [UNIFESP]; Cariello, Angelino Julio [UNIFESP]; Yu, Maria Cecília Zorat [UNIFESP]; Hofling-Lima, Ana Luisa [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
PURPOSE: To describe the demographic characteristics, associated factors and causative agents of infectious keratitis in the elderly in a tertiary referral center in São Paulo, Brazil. METHODS: A retrospective review of all patients aged 60 years and over with a presumptive diagnosis of infectious keratitis who had material collected for microbiological analysis, between the years 1975 and 2007 (32-year span). RESULTS: From a total of 7,060 age-independent cases of microbial keratitis, 1,545 cases in the elderly were reviewed, which had a mean age of 71.0 ± 7.8 years, ranging from 60 to 101 years. There were 707 males (45.6%) and 838 females (54.3%). Associated factors were: past ocular surgery (25.1%), ocular trauma (7.2%) and contact lens use (3.0%). Bacterioscopy was positive in 40.5% of cases. Culture positivity for any agent was 53.5% (bacteria 47.0%, fungi 6.1%, Acanthamoeba 0.4%). The most frequent bacteria were the gram-positive cocci (mostly coagulase-negative Staphylococci) and gram-negative bacilli (mostly the genera Pseudomonas, Moraxella and Proteus), while the most frequent fungi were the filamentous (mostly the genus Fusarium). CONCLUSIONS: This study represents a large series of microbial keratitis in the elderly in a single referral center. The most important factor associated with this condition in the elderly was past ocular surgery. The most frequent causative agents were bacteria, especially gram-positive cocci and gram-negative bacilli.
Embargo
Potencial de metabólitos secundários fúngicos na prevenção e tratamento de doenças neurodegenerativas
(Universidade Federal de São Paulo, 2021-12-15) Berardinelli, Marcos Vinicius Lourenço [UNIFESP]; Medeiros, Lívia Soman de [UNIFESP]; http://lattes.cnpq.br/7404733691134037
Estudos recentes alertam sobre o agravamento nos casos de doenças neurodegenerativas com o aumento da expectativa de vida da população mundial. Devido ao aumento de distúrbios neurológicos como Alzheimer, Parkinson e Esclerose Lateral Amiotrófica, a busca por novos tratamentos mostra-se cada vez mais importante. Neste cenário, este trabalho traz à luz o potencial de metabólitos secundários de origem fúngica, em especial do filo Ascomycota, como candidatos na busca de agentes terapêuticos para doenças neurodegenerativas e também com atuação no espectro da neuroproteção. Por meio de pesquisa bibliográfica sobre o tema, no período de 2010 a 2020, o trabalho discutirá e analisará os produtos naturais de origem fúngica relatados na literatura, mediante a seleção de importantes parâmetros como ação biológica, estrutura química e classificação biossintética. Contudo, a curadoria de dados deste trabalho poderá auxiliar em futuras investigações quanto a implementação de triagens químicas e biológicas mais focadas, com relação a bioprospecção de alvos mais promissores, visando o desenvolvimento de agentes terapêuticos que possam ser empregados no combate às doenças relacionadas ao sistema nervoso humano. Cerca de 115 artigos foram selecionados e, através de processo de triagem e anotação, observou-se um maior número de compostos com mecanismo de ação anti-inflamatório e antioxidante. Resultados mostram que a classe dos policetideos representam 44% de todos os compostos revisados, sendo a classe biossintética de maior representatividade na literatura acessada. Dentre as origens fúngicas, os fungos endofíticos apresentam destaque, representando 51% dos fungos descritos nesta revisão.
Somente Metadadados
The presence of fungi on contact electrical stimulation electrodes and ultrasound transducers in physiotherapy clinics
(Elsevier B.V., 2011-12-01) Mobin, Mitra; Borba, Cintia de Moraes; Moura Filho, Oseas F. de; Melo Neto, Antonio Quaresma de; Valenti, Vitor E. [UNIFESP]; Marques Vanderlei, Luiz Carlos; Abreu, Luiz Carlos de [UNIFESP]; Ciencias Humanas & Tecnol Piaui NOVAFAPI; Fiocruz MS; Universidade Federal de São Paulo (UNIFESP); Univ Estadual Paulista
Objectives To evaluate the presence of fungi on contact electrodes and ultrasound transducers from physiotherapy clinics.Design Quantitative study conducted at the Laboratory of Microbiology and Immunology, Faculty of Health Sciences and Technology of Piaui - NOVAFAPI, Teresina, Brazil.Setting Sample collection was performed in 10 clinics ( 20 ultrasound transducers and 20 contact electrodes).Main outcome measures Swabs were soaked with saline solution, inoculated in culture and incubated for filamentous fungi and yeast growth.Results Fourteen taxons were identified: Acremomium hyalinulum (Sacc.), Aspergillus terreus, Candida albicans, Cladosporium cladosporioides, Cladosporium elatum, Cladosporium oxysporum, Cladosporium sphaerospermum, Cladosphialophora bantiana, Curvularia clavata, Curvularia senegalensis, Fusarium oxysporum, Penicillium decumbens, Scopulariopsis candida and Sporothrix schenckii. Aspergillus terreus, Cladosporium oxysporum, Sporothrix shenckii and Candida albicans were found most often on contact electrodes, and Penicillium decumbens and Cladosporium cladosporioides were found most often on ultrasound transducers.Conclusion Fungi were found on all of the contact electrodes and ultrasound transducers. Physiotherapy professionals need to improve the disinfection procedures for this equipment. (C) 2010 Chartered Society of Physiotherapy. Published by Elsevier B.V. All rights reserved.
Somente Metadadados
Properties of a purified thermostable glucoamylase from Aspergillus niveus
(Springer, 2009-12-01) Silva, Tony Marcio da; Maller, Alexandre; Lima Damasio, Andre Ricardo de; Michelin, Michele; Ward, Richard John; Hirata, Izaura Yoshico [UNIFESP]; Jorge, Joao Atilio; Terenzi, Hector Francisco; Polizeli, Maria Lourdes T. M. de; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
A glucoamylase from Aspergillus niveus was produced by submerged fermentation in Khanna medium, initial pH 6.5 for 72 h, at 40A degrees C. the enzyme was purified by DEAE-Fractogel and Concanavalin A-Sepharose chromatography. the enzyme showed 11% carbohydrate content, an isoelectric point of 3.8 and a molecular mass of 77 and 76 kDa estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis or Bio-Sil-Sec-400 gel filtration, respectively. the pH optimum was 5.0-5.5, and the enzyme remained stable for at least 2 h in the pH range of 4.0-9.5. the temperature optimum was 65A degrees C and retained 100% activity after 240 min at 60A degrees C. the glucoamylase remained completely active in the presence of 10% methanol and acetone. After 120 min hydrolysis of starch, glucose was the unique product formed, confirming that the enzyme was a glucoamylase (1,4-alpha-d-glucan glucohydrolase). the K (m) was calculated as 0.32 mg ml(-1). Circular dichroism spectroscopy estimated a secondary structure content of 33% alpha-helix, 17% beta-sheet and 50% random structure, which is similar to that observed in the crystal structures of glucoamylases from other Aspergillus species. the tryptic peptide sequence analysis showed similarity with glucoamylases from A. niger, A. kawachi, A. ficcum, A. terreus, A. awamori and A. shirousami. We conclude that the reported properties, such as solvent, pH and temperature stabilities, make A. niveus glucoamylase a potentially attractive enzyme for biotechnological applications.
Acesso aberto (Open Access)
Prospecção de fungos com potencial celulolítico no intestino e ninho de cupins A. pacificus (Blattaria, Isoptera)
(Universidade Federal de São Paulo, 2021-02-24) Pereira, Tatiana Mesquita [UNIFESP]; Okamoto, Débora Noma [UNIFESP]; Santos, Fabiana Elaine Casarin dos [UNIFESP]; http://lattes.cnpq.br/5047065840855896; http://lattes.cnpq.br/5115280107160951; http://lattes.cnpq.br/8190230499061840
Para serem capazes de degradar a celulose, os cupins possuem um complexo trato digestório que abriga sua fauna intestinal composta por organismos dos três domínios da vida: Archaea, Eubacteria e Eucarya (protozoários e fungos) distribuídos ao longo de seu trato intestinal. Esses são responsáveis por processar as fibras de celulose e lignina, chegando a converter 95% da celulose em açúcares simples em até 24 após a ingestão. Assim, em conjunto com a atividade enzimática do próprio cupim tornam esse grupo de insetos, o de maior eficiência na degradação de celulose e lignina entre todos conhecidos. Dentre os cupins da fauna brasileira o grupo de espécies do gênero Anoplotermes é constituído por térmitas que se alimentam de celulose em estados avançados de decomposição como o húmus e solo, apesar de abundantemente presente em toda a Mata Atlântica, é considerado um dos grupos menos estudado dos cupins. Visando ampliar o entendimento clássico acerca dos grupos que compõem a microbiota intestinal dos térmitas e sua interação com os fungos no meio no qual vivem, neste trabalho foram realizadas coletas de amostras de ninho, operários e alados na Reserva Biológica da Serra do Japi (REBIO). As amostras foram plaqueadas em meio BDA, específico para fungos, e no total foram 9 (nove) amostras isoladas. A fim de entender a participação desses organismos na degradação de celulose, as culturas foram submetidas a testes qualitativos para detecção de celulase, primeiramente em meio Ágar/CMC e Mandels com posterior coloração com Vermelho Congo. Dessas, 2 (duas) amostras de fungos foram encontradas, sendo originalmente do intestino de alados. Com isso, essas duas amostras que mostram halo no teste qualitativo, foram submetidas ao teste quantitativo para detecção de FPase (atividade no papel filtro), mostrando atividade de 0,2 a 0,5 (FPU/mL); esses dados de atividade celulolítica de fungos isolados de intestino de térmitas são importantes para o entendimento da transferência da microbiota entre os cupins superiores, além de contribuir para a biotecnologia enzimática e entendimento do comportamento social desses insetos.
Restrito
Uma revisão sobre o potencial de co-culturas fúngicas na degradação de lignina
(Universidade Federal de São Paulo, 2022-01-28) Soares, Jullio Kennedy Castro [UNIFESP]; Vallim, Marcelo Afonso [UNIFESP]; Vitali, Vera Maria Valle; http://lattes.cnpq.br/6137997220541039; http://lattes.cnpq.br/4039129182586680; http://lattes.cnpq.br/2102381380357788
Atualmente a biomassa lignocelulósica corresponde a uma fonte de recurso altamente abundante e renovável, porém, sendo pouca explorada devido à recalcitrância fornecida pelo componente da lignina presente na parede vegetal, a qual pode ser superada pela degradação por co-culturas fúngicas que gradativamente estão sendo estudadas devido a maior produção de enzimas ligninolíticas, em detrimento das culturas axênicas, responsáveis pela modificação do polímero. Devido a isto, o objetivo deste trabalho é compilar os estudos experimentais de co-cultivos fúngicos na degradação da lignina e, para isto, foi adotado a metodologia de revisão da literatura do tipo sistemática buscando em onze bases de dados e mecanismos de busca os termos correspondente a este ramo de pesquisa para o levantamento de artigos científicos relevantes, publicados virtualmente nas últimas três décadas, os quais foram verificados por algumas etapas de triagem. Uma vez selecionados, os artigos científicos ainda foram submetidos à técnica Bola de Neve para a otimização da recuperação de estudos relevantes. Dentre os 43 estudos elegíveis que serviram de base para esta revisão, foi observado uma maior frequência de co-culturas fúngicas consideradas neutras (54,5%) e sinérgicas (39,8%), seguido dos raros co-cultivos antagônicos (5,7%), quanto à sua capacidade de degradar a lignina em comparação aos respectivos cultivos axênicos. Em geral, o resultado do co-cultivo se demonstra relacionado com o equilíbrio ou desbalanço dos efeitos antagônicos da competição/estresse e efeitos sinérgicos das alterações fisiológicas favoráveis. Por mais que se tenha conhecimento que as espécies pareadas, em conjunto com as condições microambientais do sistema, sejam responsáveis pelas degradabilidades relatadas, os mecanismos moleculares subjacentes às interações ainda permanecem incompreendidos. Além disso, também foi acompanhada, em geral, frequências similares para os resultados dos co-cultivos fúngicos sobre a degradação da holocelulose, decorrentes do aumento de enzimas hidrolíticas, e perda de biomassa dos substrato, em relação às correspondentes culturas isoladas. Em suma, os achados demonstram a aplicabilidade promissora de co-culturas fúngicas em setores biotecnológicos que visam intensificar a degradação de lignina e seus derivados, mediante a sua melhor compreensão em escala ecológica e industrial para a exploração de seu potencial biológico.

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