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1.
Arch Microbiol ; 205(5): 171, 2023 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-37017720

RESUMO

Concerning the potential application of the optically active isomer (R,R)-2,3-butanediol, and its production by a non-pathogenic bacterium Paenibacillus polymyxa ATCC 842, the present study evaluated the use of a commercial crude yeast extract Nucel®, as an organic nitrogen and vitamin source, at different medium composition and two airflows (0.2 or 0.5 vvm). The medium formulated (M4) with crude yeast extract carried out with the airflow of 0.2 vvm (experiment R6) allowed for a reduction in the cultivation time and kept the dissolved oxygen values at low levels until the total glucose consumption. Thus, the experiment R6 led to a fermentation yield of 41% superior when compared to the standard medium (experiment R1), which was conducted at airflow of 0.5 vvm. The maximum specific growth rate at R6 (0.42 h-1) was lower than R1 (0.60 h-1), however, the final cell concentration was not affected. Moreover, this condition (medium formulated-M4 and low airflow-0.2 vvm) was a great alternative to produce (R,R)-2,3-BD at fed-batch mode, resulting in 30 g.L-1 of the isomer at 24 h of cultivation, representing the main product in the broth (77%) and with a fermentation yield of 80%. These results showed that both medium composition and oxygen supply have an important role to produce 2,3-BD by P. polymyxa.


Assuntos
Paenibacillus polymyxa , Paenibacillus , Acetoína , Fermentação , Butileno Glicóis , Reatores Biológicos
2.
Folia Primatol (Basel) ; 92(3): 151-163, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34350867

RESUMO

Vocal communication is an essential aspect of primate social behaviour. The bearded capuchin Sapajus libidinosus is endemic to Brazil, and some studies have described specific vocalisation types for this species; however, there is still no complete description of its vocal repertoire. Thus, this study aimed to describe the vocal repertoire of a group of S. libidinosus living in theParque Nacional de Brasília, a protected area in the Cerrado area of Central Brazil. We carried out focal samplings and recording of vocalisations of members of an S. libidinosus troop in different behavioural contexts. The call analyses revealed 25 different types of vocalisations, and each call presented significant structural variation. We grouped these vocalisations according to the context of the emission or acoustic structure into the following categories: contact calls (contact note, infant babbling, trill, teeth- and lip-smacking, and sirena); foraging calls (chihui, grgr, and patinado); whistle series (food-associated, long-distance, and intergroup encounter); aggressive calls (aggressive contact note, ascending rapid staccato, cough cough, and pip); calls in response to aggression (scream, squeal, and pulsed scream), sexual display calls (chuck and raspy oestrous call), and stress-related calls (alarm call/bark, hiccup, hip, double hip, and wah wah). S. libidinosus presented a very rich vocal repertoire, revealing a pattern consistent with the repertoire of other capuchin monkey species. This is the first comprehensive description of the S. libidinosus vocal repertoire and highlights the complexity of neotropical primate communication.


Assuntos
Cebinae/psicologia , Vocalização Animal , Animais , Brasil , Feminino , Masculino
4.
Bioprocess Biosyst Eng ; 43(7): 1265-1276, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32172349

RESUMO

Lactobionic acid and sorbitol are produced from lactose and fructose in reactions catalyzed by glucose-fructose oxidoreductase and glucono-δ-lactonase, periplasmic enzymes present in Zymomonas mobilis cells. Considering the previously established laboratory-scale process parameters, the bioproduction of lactobionic acid was explored to enable the transfer of this technology to the productive sector. Aspects such as pH, temperature, reuse and storage conditions of Ca-alginate immobilized Z. mobilis cells, and large-scale bioconversion were assessed. Greatest catalyst performance was observed between pH range of 6.4 and 6.8 and from 39 to 43 °C. The immobilized biocatalyst was reused for twenty three 24-h batches preserving the enzymatic activity. The activity was maintained during biocatalyst storage for up to 120 days. Statistically similar results, approximately 510 mmol/L of lactobionic acid, were attained in bioconversion of 0.2 and 3.0 L, indicating the potential of this technique of lactobionic acid production to be scaled up to the industrial level.


Assuntos
Células Imobilizadas , Dissacarídeos/biossíntese , Zymomonas/metabolismo , Alginatos/química , Biocatálise , Cloreto de Cálcio/química , Catálise , Cromatografia Líquida de Alta Pressão/métodos , Meios de Cultura , Concentração de Íons de Hidrogênio , Temperatura
5.
Parasitology ; 146(11): 1462-1466, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31142391

RESUMO

For parasites in natural systems, the most common pattern of spatial distribution is aggregation among hosts. The main causes of such aggregation are variable exposure of hosts to parasites and heterogeneity in host susceptibility. The objective of this study was to determine if there are differences in the aggregation pattern of two species of ectoparasitic flies between the Pantanal and Cerrado regions of Brazil on the bat Artibeus planirostris. We collected the ectoparasites from bats captured between 2002 and 2017 with mist nets in 21 sites in the Pantanal and 15 sites in the surrounding plateaus. The results showed that the aggregation of ectoparasitic flies in Pantanal was more pronounced than in Cerrado. The discrepancy aggregation index (D) of the bat fly Megistopoda aranea was 0.877 in Pantanal and 0.724 in Cerrado. The D values of Aspidoptera phyllostomatis was even higher, with 0.916 and 0.848 in the Pantanal and Cerrado, respectively. Differences in the shelters used may be the main factor shaping variation in aggregation, since the Pantanal does not have rock formations, with only foliage, crowns and hollow tree trunks. These differences likely affect host exposure to the parasites, leading to an increase in parasite aggregation.


Assuntos
Quirópteros , Dípteros/fisiologia , Ecossistema , Ectoparasitoses/veterinária , Interações Hospedeiro-Parasita , Animais , Brasil/epidemiologia , Ectoparasitoses/epidemiologia , Ectoparasitoses/parasitologia
6.
J Environ Manage ; 236: 581-590, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30771677

RESUMO

In this work, phenol removal from aqueous solutions by Pleurotus sajor-caju PS-2001 phenol oxidases was assessed under different conditions. In stirred-tank reactor (STR), 77, 82, 92 and 36% of removal were attained when initial concentrations of 1.0, 2.0, 3.0 and 4.0 mmol L-1 phenol, respectively, were used. Among the different enzymes produced by this fungus, phenol removal seems to be related to the activity of laccases that attained maximum values between 33 and 91 U mL-1 in STR. With an internal-loop airlift reactor (ILAR), phenol concentrations of 1.0, 2.0, 3.0, 4.0 and 5.0 mmol L-1 were evaluated, and removal of 70, 76, 82, 77 and 82%, respectively, were observed. In ILAR, however, superior maximum titres of laccases were quantified (80-285 U mL-1). Crude enzyme broths have also been tested for phenol removal from 3.0 mmol L-1 aqueous solutions, the best result (55% of removal) being obtained at pH 3.2 and 30 °C, without agitation, using 60 U mL-1 laccases. According to the data presented, phenol can be efficiently removed from liquid media in submerged cultures of P. sajor-caju PS-2001 even when carried out in a simple pneumatic reactor, whereas significantly less amount of the pollutant is degraded when a crude enzyme broth is used.


Assuntos
Pleurotus , Lacase , Monofenol Mono-Oxigenase , Fenol , Fenóis
7.
Bioprocess Biosyst Eng ; 41(2): 185-194, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29052765

RESUMO

Equimolar amounts of lactobionic acid and sorbitol may be obtained in a reaction catalyzed by the enzymes glucose-fructose oxidoreductase and glucono-δ-lactonase, which are found in the periplasm of Zymomonas mobilis. These reactions are generally conducted using immobilized bacterial cells, and the cell treatment and immobilization steps are costly and time-consuming. This study evaluated alternatives to simplify the preparation of calcium alginate-immobilized biocatalyst and its application in different operation modes and types of reactors. It was possible to eliminate cell permeabilization with cetyltrimethylammonium bromide, and the reticulation of Z. mobilis cells with glutaraldehyde sufficed to inhibit the fermentative metabolism of carbohydrates by the bacterium, with accumulation of bioconversion products. When the process was carried out in a mechanically stirred reactor in batch mode, 530 mmol L- 1 of products were obtained in 24 h. The process was also tested in fed-batch mode so as to use of a larger amount of lactose, since it could not be used in the batch because of its low solubility in water. Under this condition, final products concentration reached 745 mmol L- 1 within 42 h. Similar results were obtained for reactions conducted in a pneumatically stirred reactor in batch and fed-batch modes, proving the potential use of this process in several industrial settings.


Assuntos
Alginatos/química , Células Imobilizadas/metabolismo , Sorbitol/metabolismo , Zymomonas/metabolismo , Ácido Glucurônico/química , Ácidos Hexurônicos/química
8.
Rev Gaucha Enferm ; 38(2): e66204, 2017 Jul 13.
Artigo em Português, Inglês | MEDLINE | ID: mdl-28723986

RESUMO

OBJECTIVE: To analyze the contributions of digital educational technologies used in teaching nursing skills. METHOD: Integrative literature review, search in five databases, from 2006 to 2015 combining the descriptors 'education, nursing', 'educational technology', 'computer-assisted instruction' or related terms in English. RESULTS: Sample of 30 articles grouped in the thematic categories 'technology in the simulation with manikin', 'incentive to learning' and 'teaching of nursing skills'. It was identified different formats of digital educational technologies used in teaching Nursing skills such as videos, learning management system, applications, hypertext, games, virtual reality simulators. CONCLUSIONS: These digital materials collaborated in the acquisition of theoretical references that subsidize the practices, enhancing the teaching and enable the use of active learning methods, breaking with the traditional teaching of demonstrating and repeating procedures.


Assuntos
Recursos Audiovisuais , Instrução por Computador , Educação em Enfermagem/métodos , Competência Clínica , Bases de Dados Bibliográficas , Humanos , Manequins , Utilização de Procedimentos e Técnicas , Jogos de Vídeo , Realidade Virtual
9.
J Ind Microbiol Biotechnol ; 40(1): 1-10, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23053345

RESUMO

In this work the periplasmic enzymatic complex glucose-fructose oxidoreductase (GFOR)/glucono-δ-lactonase (GL) of permeabilized free or immobilized cells of Zymomonas mobilis was evaluated for the bioconversion of mixtures of fructose and different aldoses into organic acids. For all tested pairs of substrates with permeabilized free-cells, the best enzymatic activities were obtained in reactions with pH around 6.4 and temperatures ranging from 39 to 45 °C. Decreasing enzyme/substrate affinities were observed when fructose was in the mixture with glucose, maltose, galactose, and lactose, in this order. In bioconversion runs with 0.7 mol l(-1) of fructose and with aldose, with permeabilized free-cells of Z. mobilis, maximal concentrations of the respective aldonic acids of 0.64, 0.57, 0.51, and 0.51 mol l(-1) were achieved, with conversion yields of 95, 88, 78, and 78 %, respectively. Due to the important applications of lactobionic acid, the formation of this substance by the enzymatic GFOR/GL complex in Ca-alginate-immobilized cells was assessed. The highest GFOR/GL activities were found at pH 7.0-8.0 and temperatures of 47-50 °C. However, when a 24 h bioconversion run was carried out, it was observed that a combination of pH 6.4 and temperature of 47 °C led to the best results. In this case, despite the fact that Ca-alginate acts as a barrier for the diffusion of substrates and products, maximal lactobionic acid concentration, conversion yields and specific productivity similar to those obtained with permeabilized free-cells were achieved.


Assuntos
Hidrolases de Éster Carboxílico/metabolismo , Oxirredutases/metabolismo , Zymomonas/enzimologia , Alginatos , Células Imobilizadas/enzimologia , Dissacarídeos/biossíntese , Frutose/metabolismo , Galactose/metabolismo , Ácido Glucurônico , Ácidos Hexurônicos , Maltose/metabolismo , Periplasma/enzimologia
10.
Appl Microbiol Biotechnol ; 94(3): 625-36, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22395904

RESUMO

The growth kinetics, sporulation, and toxicity of Bacillus thuringiensis var. israelensis were evaluated through the analysis of batch cultures with different dissolved oxygen (DO) profiles. Firstly, DO was maintained constant at 5%, 20%, or 50% throughout fermentation in order to identify the most suitable one to improve the main process parameters. Higher biomass concentration, cell productivity, and cell yield based on glucose were obtained with 50% DO. The higher aeration level also resulted in higher spore counts and markedly improved the toxic activity of the fermentation broth, which was 9-fold greater than that obtained with 5% DO (LC(50) of 39 and 329 mg/L, respectively). Subsequently, using a two-stage oxygen supply strategy, DO was kept at 50% during the vegetative and transition phases until the maximum cell concentration was achieved. Then, DO was changed to 0%, 5%, 20%, or 100% throughout sporulation and cell lysis phases. The interruption of oxygen supply strongly reduced the spore production and thoroughly repressed the toxin synthesis. On the contrary, when DO was raised to 100% of saturation, toxic activity increased approximately four times (LC(50) of 8.2 mg/L) in comparison with the mean values reached with lower DO levels, even though spore counts were lower than that from the 50% DO assay. When pure oxygen was used instead of normal air, it was possible to obtain 70% of the total biomass concentration achieved in the air assays; however, cultures did not sporulate and the toxin synthesis was consequently suppressed.


Assuntos
Bacillus thuringiensis/crescimento & desenvolvimento , Bacillus thuringiensis/metabolismo , Proteínas de Bactérias/biossíntese , Endotoxinas/biossíntese , Proteínas Hemolisinas/biossíntese , Oxigênio/metabolismo , Esporos Bacterianos/crescimento & desenvolvimento , Toxinas de Bacillus thuringiensis , Biomassa , Meios de Cultura/química , Fermentação
11.
Int J Parasitol Parasites Wildl ; 11: 261-267, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32195111

RESUMO

Leishmaniasis involves the participation of several species of both wild and domestic mammal hosts and sandfly vectors, which demonstrates the eco-epidemiological complexity observed in this disease. Bats are among the most abundant types of mammals and the scarcity of research on Leishmania infection in these animals gives evidence of the importance of new studies that aim to clarify this relationship. This study aimed to detect the Leishmania spp. in bats. 146 bats, representing 16 different species belonging to the Molossidae, Vespertilionidae, and Phyllostomidae families, were received and processed for collection of tissues. Skin samples were collected from 100% of the bats, and liver samples were collected from 87% (n = 127). After evaluating the quality of the DNA extracted by means of PCR directed to the IRBP gene, the samples considered suitable for the Leishmania detection test were submitted for PCR directed to Leishmania kDNA, and to confirm positivity, were tested to the SSUrRNA gene-directed Nested-PCR. The Leishmania presence in the species Molossus pretiosus, Nyctinomops macrotis, and Lasiurus cinereus are the first reports this encounter in these species of bats in Brazil. Furthermore, new species of bats as possible hosts for L. infantum are reported, such as Molossus pretiosus, Myotis nigricans, Nyctinomops laticaudatus, Nyctinomops macrotis, and, for L. braziliensis, Lasiurus cinereus and Cynomops planirostris. These findings in bats in an area endemic for leishmaniasis indicate that these animals may be involved in sustaining the disease cycle in this location.

12.
Curr Microbiol ; 59(6): 593-9, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19688374

RESUMO

In this study, the effect of glycine betaine as osmoprotectant compound for Gluconacetobacter diazotrophicus PAL5 was evaluated by kinetic growth parameters. Batch fermentation assays were performed employing media supplemented with different sodium chloride concentrations to simulate saline stress conditions. Salt concentrations of 50-300 mM led to decreased cell concentrations, while the maximum specific growth rates and cell productivities were reduced at concentrations above 100-mM NaCl. Salt inhibition was mainly observed in media with 200- and 300-mM NaCl, in which drastic changes in cell morphology were also noted. The addition of glycine betaine to the media showed to be efficient to counteract the salt inhibitory effect by increasing some fermentation parameters. However, the osmoprotectant was not able to revert the polymorphism promoted by higher salt concentrations.


Assuntos
Betaína/farmacologia , Gluconacetobacter/efeitos dos fármacos , Meios de Cultura/farmacologia , Gluconacetobacter/crescimento & desenvolvimento , Fixação de Nitrogênio/efeitos dos fármacos , Cloreto de Sódio/farmacologia , Equilíbrio Hidroeletrolítico/efeitos dos fármacos
13.
J Ind Microbiol Biotechnol ; 36(1): 1-9, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18758836

RESUMO

Some conditions in media composition for laccases production, such as different sources of carbon and organic nitrogen, antifoams and a surfactant, were studied in liquid cultures of Pleurotus sajor-caju strain PS-2001. Cultivation with fructose or glucose as carbon sources produced maximum enzyme activities of 37 and 36 U mL(-1), respectively. When sucrose was present in the medium, the best results were obtained using 5 g L(-1) of this carbohydrate, on the 11th day of the process, attaining laccase titres of 13 U mL(-1). In a medium without casein, practically no enzyme was produced during the experiments; among the sources of nitrogen studied, pure casein led to the highest titres of laccase activity. Different concentrations of pure casein and sucrose were also tested. As to the different concentrations of casein, the addition of 1.5 g L(-1) resulted in the highest titres of laccase activity. Negligible levels of manganese peroxidase activity were also detected in the culture medium. In low concentrations, polypropylene glycol or silicon-based antifoams and the surfactant Tween 80 have no significant influence on the formation of laccases by P. sajor-caju. However, enhanced concentration of polypropylene glycol negatively affected the production of laccases but favored the titres in total peroxidases, lignin peroxidase and veratryl alcohol oxidase.


Assuntos
Carbono/metabolismo , Técnicas de Cultura , Proteínas Fúngicas/metabolismo , Lacase/metabolismo , Nitrogênio/metabolismo , Pleurotus/enzimologia , Meios de Cultura/química , Meios de Cultura/metabolismo , Proteínas Fúngicas/genética , Lacase/genética , Pleurotus/genética , Pleurotus/crescimento & desenvolvimento , Polímeros/química , Polissorbatos/química , Propilenoglicóis/química , Silício/química
14.
J Pharm Biomed Anal ; 174: 104-114, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31163344

RESUMO

The bioproduction of lactobionic acid and its salts can be performed by enzymatic complex glucose-fructose oxidoreductase (GFOR) and glucono-δ-lactonase (GL) of Zymomonas mobilis. Considering the applicability of these compounds in pharmaceutical area, the aim of this study was to assess the accelerated and long-term stability studies of sodium, potassium, calcium lactobionate, and lactobionic acid. Furthermore, stress tests were performed to evaluate the stability against pH, temperature and oxidation. The samples submitted to degradation tests were analyzed by high-performance liquid chromatography (HPLC) and high-resolution mass spectrometry analysis (HRMS-ESI-QTOF). Sodium, potassium, and calcium lactobionate were stable for six months of analyses considering the accelerated (40 °C and 75% RH) and long-term (30 °C and 75% RH) stability studies. The presence of lactobiono-δ-lactone and a significant increase in moisture were observed for both biosynthesized and commercially available lactobionic acid samples. Against the forced degradation tests, all the lactobionate salts and lactobionic acid showed to be stable upon alkaline and acid pH conditions, at 60 and 80 °C, and also against UV light exposition. Furthermore, the presence of lactobiono-δ-lactone form was observed in lactobionic acid samples. However, the degradation of both lactobionic acid and lactobionate salts was evident in the presence of hydrogen peroxide. This degradation kinetic profile suggests, that lactobionate salts follows a zero-order reaction model and lactobionic acid follows a second-order kinetic. The MS analysis of the main degradation product suggests a molecular formula C11H20O10 resulting from the oxidative decarboxylation. This report brings an amount of results as contribution to the scarce information regarding the chemical and physical-chemical stability of sodium, potassium, calcium lactobionate, and lactobionic acid. These data may be useful and serve as reference, in view of the multipurpose applications of the cited compounds.


Assuntos
Cálcio/química , Dissacarídeos/química , Potássio/química , Sódio/química , Zymomonas/química , Reatores Biológicos , Descarboxilação , Estabilidade de Medicamentos , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Cinética , Lactonas , Espectrometria de Massas , Estresse Oxidativo , Oxirredutases/química , Oxigênio/química , Temperatura , Raios Ultravioleta
15.
Rev Assoc Med Bras (1992) ; 64(11): 997-1001, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30570050

RESUMO

OBJECTIVE: Atopic dermatitis is a common skin disease. Its increased incidence has changed the focus of research on atopic dermatitis toward epidemiology, prevention, and treatment. METHODS: Evidence suggests that intestinal microbiota plays an important role in the pathogenesis of atopic dermatitis inducing immunosuppression, but its exact mechanism is still unclear. Probiotics have been widely reported to act on the immune system. They are living microorganisms with immunomodulatory effects that stimulate Th1 cytokines and suppress the Th2 response, which are being researched for the treatment of several diseases. Probiotics most commonly used are part of the intestinal microflora like lactobacilli, bifidobacteria, and enterococci. RESULTS: We describe here a case of evident response to the use of probiotics in a girl with severe atopic dermatitis, with a significant change in severity scores of atopic dermatitis (BSA/SCORAD/FDLQI). CONCLUSIONS: Modulation of the intestinal microbiota with probiotics may offer a way to prevent or treat allergic diseases, including atopic dermatitis.


Assuntos
Dermatite Atópica/terapia , Probióticos/uso terapêutico , Citocinas , Dermatite Atópica/microbiologia , Dermatite Atópica/fisiopatologia , Feminino , Humanos , Sistema Imunitário/fisiopatologia , Lactente , Lactobacillus/classificação , Pele/patologia , Células Th1 , Células Th2
16.
J Chromatogr A ; 1145(1-2): 128-32, 2007 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-17306812

RESUMO

Experimental conditions for complete separation and quantification of mixtures containing lactobionic acid, sorbitol, lactose and fructose are discussed for the first time. These mixtures appear in the enzymatic bioconversion of fructose and lactose catalyzed by glucose-fructose oxidoreductase (GFOR) and glucono-delta-lactonase (GL) enzymes of Zymomonas mobilis cells. The high-performance liquid chromatography (HPLC) separation was carried out in a strong cation ion exchange resin (hydrogen form) based on a copolymer of styrene divinylbenzene (PS-DVB). A stationary phase of beta-cyclodextrin was also evaluated. An efficient separation was obtained with PS-DVB column eluted with sulfuric acid 0.450 mM solutions (pH 3.0-3.2) at 75 degrees C. The formation of lactones was observed, which is associated with the dissolution of lactobionic acid crystals; however, by dissolving the lactobionic acid crystals on alkaline calcium hydroxyde solution in equimolar ratio a single lactobionic acid chromatographic peak without lactobionolactone is obtained.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Dissacarídeos/análise , Frutose/química , Lactose/química , Sorbitol/análise , Resinas de Troca de Cátion/química , Dissacarídeos/química , Dissacarídeos/isolamento & purificação , Reprodutibilidade dos Testes , Sorbitol/química , Sorbitol/isolamento & purificação , beta-Ciclodextrinas/química
17.
Acta Trop ; 172: 217-222, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28502644

RESUMO

In the New World genus Leishmania parasites are etiological agents of neglected zoonoses known as leishmaniasis. Its epidemiology is very complex due to the participation of several species of sand fly vectors and mammalian hosts, and man is an accidental host. Control is very difficult because of the different epidemiological patterns of transmission observed. Studies about Leishmania spp. infection in bats are so scarce, which represents a large gap in knowledge about the role of these animals in the transmission cycle of these pathogens, especially when considering that Chiroptera is one of the most abundant and diverse orders among mammals. Leishmaniasis in Mato Grosso do Sul, Brazil are remarkably frequent, probably due to the abundance of its regional mastofauna. The recent record of L. braziliensis in bats from this state indicates the need to clarify the role of these mammals in the transmission cycle. In this study we evaluated the presence of Leishmania parasites in the skin of different species of bats, using PCR directed to Leishmania spp. kDNA for screening followed by PCR/RFLP analysis of the hsp70 gene for the identification of parasite species. Leishmania species identification was confirmed by PCR directed to the G6PD gene of L. braziliensis, followed by sequencing of the PCR product. Samples from 47 bats were processed, of which in three specimens (6.38%) was detected the presence of Leishmania sp. kDNA. PCR/RFLP and sequencing identified the species involved in the infection as L. braziliensis in all of them. This is the first report of Leishmania braziliensis in bats from Pantanal ecosystem and the first record of this species in Platyrrhinus lineatus and Artibeus planirostris, bats with a wide distribution in South America. These results reinforce the need to deepen the knowledge about the possibility of bats act as reservoirs of Leishmania spp. especially considering their ability of dispersion and occupation of anthropic environments.


Assuntos
Quirópteros/parasitologia , Leishmania braziliensis/isolamento & purificação , Leishmaniose Cutânea/veterinária , Animais , Brasil/epidemiologia , DNA de Cinetoplasto/genética , Humanos , Leishmania braziliensis/genética , Leishmaniose Cutânea/parasitologia , Áreas Alagadas , Zoonoses
18.
Biota Neotrop. (Online, Ed. ingl.) ; 20(2): e20190821, 2020. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1089122

RESUMO

Abstract: Thyropteridae is a family of bats endemic to the Neotropical region, and Thyroptera devivoi is the only species in the family that occurs exclusively in forest patches within savannas of northern South America and north of the Brazilian Cerrado. Primary data on the species are still scarce. Therefore, in this study our objective was to fill knowledge gaps on geographical distribution, roost-use, and echolocation for the species. We observed a T. devivoi colony of 15 individuals living under a dead palm leaf. The bats used the leaf as a roost for at least four days. After capturing one individual, we confirmed the species identification via skull size and the oblong shape of the adhesive disk. The new record reinforces the association of this species with non-forested formations, and its occurrence mainly in savannas. Echolocation calls of T. devivoi are consistent with those known for the genus, with multiharmonic, low intensity and high frequency pulses. Despite these new data, more studies are certainly needed to enhance distribution data for the species, as well as to clarify the biological and ecological requirements of the species.


Resumo: Thyropteridae é uma família de morcegos endêmica da região Neotropical e Thyroptera devivoi é a única espécie da família que ocorre exclusivamente em manchas florestais das savanas do norte de América do Sul e do Cerrado Brasileiro. Dados primários da espécie são ainda escassos e o objetivo deste estudo foi preencher lacunas de conhecimento sobre distribuição geográfica, uso de abrigos e padrões de ecolocalização da espécie. Nós observamos uma colônia de T. devivoi com 15 indivíduos vivendo sob uma folha morta de palmeira. Os morcegos usaram a folha como abrigo ao menos por quatro dias. Depois de capturar um indivíduo, nós confirmamos a identificação da espécie por meio da morfologia do crânio e do disco adesivo. O novo registro reforça a associação da espécie com formações não florestais e a ocorrência principalmente em savanas. Os chamados de ecolocalização de T. devivoi são consistentes com o conhecido para o gênero, com pulsos multi-harmônicos de baixa intensidade e alta frequência. A despeito destes novos dados, mais estudos são certamente necessários para aprimorar os dados de distribuição assim como os requerimentos biológicos da espécie.

19.
Braz. arch. biol. technol ; 63: e20190015, 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1132271

RESUMO

Abstract (1) Background: Oxygen supply is an important parameter to be considered in submerged cultures. This study evaluated the influence of different conditions for dissolved oxygen (DO) concentration on laccases activities and growth of Pleurotus sajor-caju PS-2001 in submerged process in stirred-tank bioreactor. (2) Methods: Initially, three different conditions were tested: uncontrolled DO and minimum levels of 30% and 80% of saturation, with the pH controlled between 4.5 and 7.0. (3) Results: Best results were observed at 30% DO (26 U mL-1 of laccases at 96 h), whereas higher mycelial biomass was observed at 30% and 80% DO (above 4.5 g L-1). Four different conditions of DO (uncontrolled, 10%, 30% and 50% of saturation) were tested at pH 6.5, with higher laccases activity (80 U mL-1 at 66 h) and lower mycelial growth (1.36 g L-1 at 90 h) being achieved with DO of 30%. In this test, the highest values for volumetric productivity and specific yield factor were determined. Under the different pH conditions tested, the production of laccases is favoured at DO concentration of 30% of saturation, while superior DO levels favours fungal growth. (4) Conclusion: The results indicate that dissolved oxygen concentration is a critical factor for the culture of P. sajor-caju PS-2001 and has important effects not only on laccases production but also on fungal growth.


Assuntos
Oxigênio Dissolvido , Biomassa , Reatores Biológicos , Pleurotus/crescimento & desenvolvimento , Pleurotus/enzimologia , Lacase/biossíntese
20.
Appl Biochem Biotechnol ; 118(1-3): 321-36, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15304760

RESUMO

Sorbitol, a polyol found in many fruits, is attracting increasing industrial interest as a sweetener, humectant, texturizer, and softener. It is principally produced by chemical means. The bacterium Zymomonas mobilis is able to produce sorbitol together with gluconic acid from fructose and glucose, respectively. This is possible in a one-step reaction via the enzyme glucose-fructose oxidoreductase, so far only known from Z. mobilis. The possibilities for the production of sorbitol by Z. mobilis are discussed also under the aspect of an industrial process and compared with the current chemical as well as other microbiologic processes. The production process by Z. mobilis shows economic possibilities for certain countries, such as Brazil, considering only the products sorbitol and ethanol as an important byproduct. For the other byproduct, gluconic acid, further studies for its partial substitution must be conducted.


Assuntos
Biotecnologia , Sorbitol/metabolismo , Gluconatos/metabolismo , Mutação , Oxirredutases/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Sorbitol/síntese química , Fatores de Tempo , Zymomonas/enzimologia , Zymomonas/metabolismo
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