Fusarium species associated with citrus blackfly (Aleurocanthus woglumi) from an agroecological polyculture in Brazil, including an augmented description of F. volatile.

The objectives of this study were to report Fusarium species associated with Aleurocanthus woglumi (Hemiptera: Aleyrodidae) collected from citrus leaves from an agroecological polyculture in Brazil, assess sexual reproductive mode of the species with unknown sexual stages, and provide an augmented description of F. volatile, for which we discovered a sexual stage. Nineteen Fusarium isolates were recovered from A. woglumi. These fungi belong to three species complexes, i.e., the F. chlamydosporum species complex (FCSC), the F. fujikuroi species complex (FFSC), and the F. incarnatum-equiseti species complex (FIESC). Based on multilocus phylogenetic analyses, the species were identified as F. annulatum, F. chlamydosporum, F. pernambucanum, F. sulawesiense, F. verticillioides, and F. volatile. Our results suggest that three species whose sexual stages are unknown (F. chlamydosporum, F. sulawesiense, and F. volatile) are also heterothallic. Intraspecific crosses of F. sulawesiense and F. volatile produced protoperithecia, whereas 66.7% of F. volatile crosses produced fertile perithecia. We provide an augmented description of the latter species to include characteristics of its sexual morph and those observed in the asexual morph that had not yet been described for the species. This study highlights the potential of researching insect-associated fungi to increase knowledge about the diversity, taxonomy, and versatility of Fusarium in ecosystems.

Optimization of L-glutaminase production by Monascus ruber URM 8542 isolated from ice cream industrial effluent.

L-glutaminase is a hydrolytic enzyme with wide biotechnological applications. Mostly, these enzymes are employed in the feed industry for flavor enhancement and acrylamide mitigation. Also, L-glutaminase may have antiviral and antineoplastic effects making it a good choice for pharmaceutical applications. In this study, the strain Monascus ruber URM 8542 was identified through classical and molecular taxonomy using partial sequencing of ß-tubulin and calmodulin genes. Subsequently, the optimal culture conditions were evaluated by submerged fermentation (L-glutamine 10 g.L- 1) for L-glutaminase excretion. The isolate was identified as M. ruber URM 8542 which showed significant extracellular enzyme production with a yield of 11.4 times in relation to the specific activity of intracellular L-glutaminase. Regarding the optimization experiments, several factors such as L-glutamine concentration, temperature, and pH were compared using a full factorial design (23). The concentrations greater than 1% proved to be significantly better for glutaminase production (R2 = 0.9077). Additionally, the L-glutaminase was optimally active at pH 7.0 and 30 ºC. The L-glutaminase was remarkably stable across an alkaline pH range (7.0-8.0) and had a thermal stability ranging from 30 ºC to 60 ºC for 1 h. Taken together, these findings suggest that the L-glutaminase produced by M. ruber is a promising candidate for pharmacological application, although further studies need to be performed. To the best of our knowledge, this is the first report of L-glutaminase production by Monascus ruber.

Molecular identification of Brazilian Fusarium strains: sources of proteases with milk-clotting properties.

Fusarium is a genus of ubiquitous fungi that comprises mycotoxigenic animal and plant pathogens. These fungi have the ability to exploit a wide range of substrates and hosts, indicating their great potential for enzyme production; however, this aspect is understudied. Therefore, the present study aimed for revaluating the identity of twenty-three Fusarium strains maintained in the University Recife Mycology (URM) culture collection, Brazil, and to evaluate their potential for proteases production and the milk-clotting activity of these proteases. According to phylogenetic analysis of translation elongation factor 1-alpha (TEF1) gene partial sequences, these strains belonged to 12 species representing four species complexes: Fusarium concolor, F. fujikuroi, F. incarnatum-equiseti, and F. oxysporum. Four of these species are putatively novel to science. Notably, novel associations of Fusarium spp. with certain hosts/substrates were documented. The proteolytic activity ranged from 1.67 U ml-1 to 22.03 U ml-1 among the evaluated fungal isolates, with specific proteolytic activity reaching 205.86 U mg-1. The values for coagulant activity and specific activity were up to 157.14 U ml-1 and 1,424.11 U mg-1, respectively. These results indicate the potential of URM Fusarium strains as a source for the production of enzymes of industrial interest. Additionally, they reinforce the importance of applying DNA-based methods for reviewing the identification of fungal strains preserved in biodiversity repositories.

Evaluation of Mycotoxin Production and Phytopathogenicity of the Entomopathogenic Fungi Fusarium caatingaense and F. pernambucanum from Brazil.

Fusarium incarnatum-equiseti species complex (FIESC) is considered as one of the richest insecticolous species. Fusarium species synthesize toxic secondary metabolites that are not fully understood. Mycotoxin production and pathogenicity on germinating seeds, seedlings, and leaves must be carefully studied for the use of Fusarium species in the biological control of insect pests. In this study, we evaluated the mycotoxin production and phytopathogenic potential of entomopathogenic strains of Fusarium sulawesiensis (1), F. pernambucanum (3), and F. caatingaense (23). The phytopathogenicity tests of F. caatingaense (URM 6776, URM 6777, URM 6778, URM 6779, and URM 6782) were performed during the development of bean (Phaseolus vulgaris, Vigna unguiculata, and Phaseolus lunatus), and corn (Zea mays) seedlings, using four treatments (soil infestation with the inoculum, spraying on leaves, root dip, and negative control). The mycotoxins, monoacetyl-deoxynivalenols (AcDON), deoxynivalenol (DON), beauvericin (BEA), fusarenone-X (FUS), T-2 toxin (T2), diacetoxyscirpenol (DAS), and zearalenone (ZEA), were detected in the study; BEA (detected in 25 strains) and FUS (detected in 21 strains) were found to be predominant. None of the strains showed any ability to cause disease or virulence in beans and corn. The FIESC strains showed a highly variable production of mycotoxins without the potential to be used as phytopathogenic agents for the cultures tested.

Morphology, phylogeny, and sexual stage of Fusarium caatingaense and Fusarium pernambucanum, new species of the Fusarium incarnatum-equiseti species complex associated with insects in Brazil.

Based on morphological and molecular phylogenetic markers and the fertility of sexual crosses, two novel species of Fusarium associated with Dactylopius opuntiae (Hemiptera: Dactylopiidae) and Aleurocanthus woglumi (Hemiptera: Aleyrodidae) from northeastern Brazil are described as Fusarium caatingaense and F. pernambucanum. Partial sequences of five loci were generated for 29 entomopathogenic Fusarium isolates. Multilocus phylogenetic analyses demonstrated that F. caatingaense and F. pernambucanum belong to the Incarnatum clade of the Fusarium incarnatum-equiseti species complex (FIESC). These species displayed common morphological characters such as the production of various types of aerial conidia formed on monophialides and polyphialides and differ from each other mainly in the dimensions and morphology of their sporodochial conidia. Mating type polymerase chain reaction (PCR) revealed 17 MAT1-1 isolates and 12 MAT1-2 isolates, all of them heterothallic. Fertile perithecia were produced in 4.2% of infraspecific crosses of F. caatingaense and in 13.3% of infraspecific crosses of F. pernambucanum after 2-3 wk. Crosses between F. caatingaense and F. pernambucanum did not result in fertile perithecia. We demonstrate the existence of a sexual stage in species of the Incarnatum clade and describe the morphological characters of these sexual morphs for the first time. These results suggest that previously unknown sexual cycles contribute to the high genetic diversity within FIESC.

Elastin increases biofilm and extracellular matrix production of Aspergillus fumigatus

Abstract Aspergillus fumigatus is an opportunistic saprobe fungus that accounts for 90% of cases of pulmonary aspergillosis in immunosuppressed patients and is known for its angiotropism. When it reaches the respiratory tract, A. fumigatus interacts with structural components and blood vessels of the lungs, such as elastin. To understand the effect of this structural component, we examined the effect of elastin on the production and development of the biofilm of A. fumigatus. In RPMI containing 10 mg/mL of elastin, a significant increase (absorbance p < 0.0001; dry weight p < 0.0001) in the production of biofilm was observed in comparison to when RPMI was used alone, reaching a maximum growth of 18.8 mg (dry weight) of biofilm in 72 h. In addition, elastin stimulates the production (p = 0.0042) of extracellular matrix (ECM) and decreases (p = 0.005) the hydrophobicity during the development of the biofilm. These results suggest that elastin plays an important role in the growth of A. fumigatus and that it participates in the formation of thick biofilm.

Elastin increases biofilm and extracellular matrix production of Aspergillus fumigatus.

Aspergillus fumigatus is an opportunistic saprobe fungus that accounts for 90% of cases of pulmonary aspergillosis in immunosuppressed patients and is known for its angiotropism. When it reaches the respiratory tract, A. fumigatus interacts with structural components and blood vessels of the lungs, such as elastin. To understand the effect of this structural component, we examined the effect of elastin on the production and development of the biofilm of A. fumigatus. In RPMI containing 10mg/mL of elastin, a significant increase (absorbance p<0.0001; dry weight p<0.0001) in the production of biofilm was observed in comparison to when RPMI was used alone, reaching a maximum growth of 18.8mg (dry weight) of biofilm in 72h. In addition, elastin stimulates the production (p=0.0042) of extracellular matrix (ECM) and decreases (p=0.005) the hydrophobicity during the development of the biofilm. These results suggest that elastin plays an important role in the growth of A. fumigatus and that it participates in the formation of thick biofilm.

Polyphasic Approach Including MALDI-TOF MS/MS Analysis for Identification and Characterisation of Fusarium verticillioides in Brazilian Corn Kernels.

Fusarium verticillioides is considered one of the most important global sources of fumonisins contamination in food and feed. Corn is one of the main commodities produced in the Northeastern Region of Brazil. The present study investigated potential mycotoxigenic fungal strains belonging to the F. verticillioides species isolated from corn kernels in 3 different Regions of the Brazilian State of Pernambuco. A polyphasic approach including classical taxonomy, molecular biology, MALDI-TOF MS and MALDI-TOF MS/MS for the identification and characterisation of the F. verticillioides strains was used. Sixty F. verticillioides strains were isolated and successfully identified by classical morphology, proteomic profiles of MALDI-TOF MS, and by molecular biology using the species-specific primers VERT-1 and VERT-2. FUM1 gene was further detected for all the 60 F. verticillioides by using the primers VERTF-1 and VERTF-2 and through the amplification profiles of the ISSR regions using the primers (GTG)5 and (GACA)4. Results obtained from molecular analysis shown a low genetic variability among these isolates from the different geographical regions. All of the 60 F. verticillioides isolates assessed by MALDI-TOF MS/MS presented ion peaks with the molecular mass of the fumonisin B1 (721.83 g/mol) and B2 (705.83 g/mol).

Aspergillus andPenicillium (Eurotiales: Trichocomaceae) in soils of the Brazilian tropical dry forest: diversity in an area of environmental preservation

ResumenEl suelo es un sistema biológico complejo, que desempeña un papel fundamental en las plantas y los animales, especialmente en los bosques secos como la Caatinga. Los hongos del suelo, tales como Aspergillus y Penicillium, pueden ser utilizados como bioindicadores para la conservación de la biodiversidad. El objetivo de este estudio fue aislar e identificar las especies de Aspergillus y Penicillium del suelo, en los municipios de Ibimirim y Tupanatinga en el Parque Nacional Catimbau. Cinco colecciones se llevaron a cabo en cada área durante la estación seca de 2012, un total de 25 muestras de suelos por área. Los hongos fueron aislados mediante la suspensión en agua destilada estéril y se sembraron en medio de cultivo Agar Sabouraud más Cloranfenicol y Rosa de Bengala, y también en el medio Agar Dicloran Glicerol. Los aislamientos fueron identificados en el Laboratorio de Colección de Hongos y se confirmaron por secuenciación del espaciador transcrito interno de ADN. Un total de 42 especies fueron identificadas, 22 de ellas pertenecientes al género Aspergillus y 20 al género Penicillium. Los aislamientos de Penicillium mostraron una distribución uniforme en Tupanatinga con índices de uniformidad entre 0.92 y 0.88 en Ibimirim. Entre los aislamientos de Aspergillus el valor encontrado en Tupanatinga (0.85) fue muy similar al encontrado en Ibimirim (0.86). Se observó una gran diversidad y bajo predominio de hongos en las muestras de suelo. Estos resultados contribuyen a la estimación de la diversidad de hongos en ambientes secos, especialmente en la Caatinga, donde la diversidad es decreciente en los suelos que han sufrido alteraciones.

Abstract Soil is a complex biological system that plays a key role for plants and animals, especially in dry forests such as the Caatinga.Fungi from soils, such as Aspergillus and Penicillium, can be used as bioindicators for biodiversity conservation. The aim of this study was to isolate and identify species of Aspergillus and Penicillium in soil, from the municipalities of Tupanatinga and Ibimirim, with dry forests, in the Catimbau National Park. Five collections were performed in each area during the drought season of 2012, totaling 25 soil samples per area. Fungi were isolated by suspending soil samples in sterile distilled water and plating on Sabouraud Agar media plus Chloramphenicol and Rose Bengal, and Glycerol Dicloran Agar. Isolates were identified by morphological taxonomy in the Culture Collection Laboratory and confirmed by sequencing of the Internal Transcribed Spacer of rDNA. A total of 42 species were identified, of which 22 belong to the genus Aspergillus and 20 to Penicillium. Penicillium isolates showed uniform distribution from the collecting area in Tupanatinga, and the evenness indices found were 0.92 and 0.88 in Tupanatinga and Ibimirim, respectively. Among isolates of Aspergillus evenness, the value found in Tupanatinga (0.85) was very close to that found in Ibimirim (0.86). High diversity and low dominance of fungi in soil samples was observed. These results contributed to the estimation of fungal diversity in dry environments of the Caatinga, where diversity is decreasing in soils that have undergone disturbance. Rev. Biol. Trop. 64 (1): 45-53. Epub 2016 March 01.

Aspergillus and Penicillium (Eurotiales: Trichocomaceae) in soils of the Brazilian tropical dry forest: diversity in an area of environmental preservation.

Soil is a complex biological system that plays a key role for plants and animals, especially in dry forests such as the Caatinga. Fungi from soils, such as Aspergillus and Penicillium, can be used as bioindica- tors for biodiversity conservation. The aim of this study was to isolate and identify species of Aspergillus and Penicillium in soil, from the municipalities of Tupanatinga and Ibimirim, with dry forests, in the Catimbau National Park. Five collections were performed in each area during the drought season of 2012, totaling 25 soil samples per area. Fungi were isolated by suspending soil samples in sterile distilled water and plating on Sabouraud Agar media plus Chloramphenicol and Rose Bengal, and Glycerol Dicloran Agar. Isolates were identified by morphological taxonomy in the Culture Collection Laboratory and confirmed by sequencing of the Internal Transcribed Spacer of rDNA. A total of 42 species were identified, of which 22 belong to the genus Aspergillus and 20 to Penicillium. Penicillium isolates showed uniform distribution from the collecting area in Tupanatinga, and the evenness indices found were 0.92 and 0.88 in Tupanatinga and Ibimirim, respectively. Among isolates of Aspergillus evenness, the value found in Tupanatinga (0.85) was very close to that found in Ibimirim (0.86). High diversity and low dominance of fungi in soil samples was observed. These results con- tributed to the estimation of fungal diversity in dry environments of the Caatinga, where diversity is decreasing in soils that have undergone disturbance.

Differential expression of the pr1A gene in Metarhizium anisopliae and Metarhizium acridum across different culture conditions and during pathogenesis.

The entomopathogenic fungi of the genus Metarhizium have several subtilisin-like proteases that are involved in pathogenesis and these have been used to investigate genes that are differentially expressed in response to different growth conditions. The identification and characterization of these proteases can provide insight into how the fungus is capable of infecting a wide variety of insects and adapt to different substrates. In addition, the pr1A gene has been used for the genetic improvement of strains used in pest control. In this study we used quantitative RT-PCR to assess the relative expression levels of the pr1A gene in M. anisopliae and M. acridum during growth in different culture conditions and during infection of the sugar cane borer, Diatraea saccharalis Fabricius. We also carried out a pathogenicity test to assess the virulence of both species against D. saccharalis and correlated the results with the pattern of pr1A gene expression. This analysis revealed that, in both species, the pr1A gene was differentially expressed under the growth conditions studied and during the pathogenic process. M. anisopliae showed higher expression of pr1A in all conditions examined, when compared to M. acridum. Furthermore, M. anisopliae showed a greater potential to control D. saccharalis. Taken together, our results suggest that these species have developed different strategies to adapt to different growing conditions.

Biological insect control using Metarhizium anisopliae: morphological, molecular, and ecological aspects / Controle biológico de insetos utilizando Metarhizium anisopliae: aspectos morfológicos, moleculares e ecológicos

Microbial control of insects is based on the rational use of pathogens to maintain environmentally balanced pest population levels, and Metarhizium anisopliae has been the most studied and most utilized fungal species for that purpose. The natural genetic variability of entomopathogenic fungi is considered one of the principal advantages of microbial insect control. The inter- and intraspecific variability and the genetic diversity and population structures of Metarhizium and other entomopathogenic fungi have been examined using ITS-RFLP, ISSR, and ISSP molecular markers. The persistence of M. anisopliae in the soil and its possible effects on the structures of resident microbial communities must be considered when selecting isolates for biological insect control.

O controle microbiano consiste na utilização racional de patógenos, visando à manutenção da população de insetos em equilíbrio no ambiente. Metarhizium anisopliae é a espécie mais estudada e utilizada no controle biológico de insetos. A variabilidade genética dos fungos entomopatogênicos pode ser considerada uma das principais vantagens no controle microbiano de insetos e pode ser detectada por meio de marcadores moleculares, como ITS-RFLP, ISSR e ISSP. Esses marcadores são usados para a caracterização inter e intraespecífica de Metarhizium e outros fungos entomopatogênicos e poderão auxiliar na compreensão da diversidade genética e da estrutura das populações destes fungos. A persistência de M. anisopliae no solo e seu possível efeito na estrutura da comunidade microbiana deste solo são características importantes e pouco estudadas, que devem ser consideradas no processo de seleção de isolados para o controle biológico de insetos.

Fungemia by Candida pelliculosa (Pichia anomala) in a neonatal intensive care unit: a possible clonal origin.

Neonatal candidemia can occur, however, infections caused by Candida pelliculosa are rare. Here, we describe an outbreak of candidemia caused by C. pelliculosa among babies hospitalized in a neonatal intensive care unit.

Invasive infection in an acute myeloblastic leukemia patient due to triazole-resistant Candida tropicalis.

Non-albicans Candida species are being increasingly reported as causes of nosocomial fungal infections. For example, invasive candidiasis caused by C. tropicalis has been associated with hematologic malignancies. In this study, we report a fatal case of fungemia and a possible urinary and pulmonary infection in a leukemia patient that was due to a strain of C. tropicalis resistant to 2 triazole antifungals.

Differential pathogenicity of Metarhizium anisopliae and the control of the sugarcane root spittlebug Mahanarva fimbriolata

In order to assess the effectiveness of Metarhizium anisopliae var. anisopliae (Metschnikoff) Sorokin isolates in controlling the sugarcane root spittlebug Mahanarva fimbriolata (Stal) (Hemiptera: Cercopidae), nine isolates obtained from a single geographical region were studied. 'Confirmed cumulative' and 'corrected cumulative' spittlebug mortality rates were measured for each of the isolates. Based on the confirmed mortality curve, the isolates URM5946, URM5951 and URM6033 were considered to be potentially the most effective in a biological control program for M. fimbriolata.

Trichosporon inkin Esophagitis: An Uncommon Disease in a Patient with Pulmonary Cancer.

Trichosporon species are usually opportunistic pathogens. Here, we present a case of esophagitis caused by T. inkin in a 54-year-old woman with pulmonary cancer and severe neutropenia in whom the susceptibility profile of the isolate against azoles and polyenes was verified. The patient was diagnosed with esophagitis grade I of Wilcox, presenting scattered whitish plaques and exudates in upper two-thirds of the esophageal mucosa. Antifungal therapy involving oral fluconazole (150 mg/day for 14 days) was ineffective. In vitro, the isolate showed no resistance to this azole and sensitivity to amphotericin B. Since T. inkin is of growing importance as an agent of invasive infections in immunocompromised patients, we stress that the diagnosis of esophagitis by this species should be followed by an assessment of the therapeutic sensitivity of the strain involved.

Amplification of the cap20 pathogenicity gene and genetic characterization using different markers molecular in Colletotrichum gloeosporioides isolates

Studies were performed to analyze the genetic characterization using RFLP-ITS and Intron (primer EI1) markers and the amplification of the cap20 pathogenicity gene by PCR in Colletotrichum gloeosporioides isolates of different hosts plant. The genetic variability was accessed using RFLP-ITS and Intron markers and grouping by UPGMA method. Primers to cap20 gene were constructed using selected sequences of the GenBank (National Center of Biotechnology Information, http://www.ncbi.nlm.nih.gov) with the Primer 3 program. The dendrograms analysis showed that the RFLP-ITS marker was more informative to separate the Colletotrichum sp, and that primer EI1 demonstrated greater genetic diversity. The amplification of the DNA of the Colletotrichum isolates to the cap20 gene with primers P1 and P2 indicated that this gene could present variations into C. gloeosporioides related with the host, and also that it was present in other Colletotrichum sp.

Estudos foram realizados para analisar a caracterização genética usando marcadores de RFLP-ITS e ISSP e a amplicação do gene de patogenicidade cap20 por PCR em isolados de Colletotrichum gloeosporioides de diferentes hospedeiros. Primers para o gene cap20 foram construídos a partir de seqüências selecionadas do GenBank (National Center of Biotechnology Information, http://www.ncbi.nlm.nih.gov) com o programa Primer 3. A análise dos dendrogramas revelou que o marcador RFLP-ITS foi mais informativo em separar as espécies de Colletotrichum, e que o primer EI1 evidenciou maior diversidade genética. A amplificação do DNA dos isolados de Colletotrichum para o gene cap20 com os primers P1 e P2 indicou que este gene pode apresentar variações dentro de C. gloeosporioides relacionada ao hospedeiro, e que também está presente em outras espécies de Colletotrichum.

Biological and chemical control of Sclerotinia sclerotiorum using Trichoderma spp. and Ulocladium atrum and pathogenicity to bean plants

Four isolates of Sclerotinia sclerotiorum were tested for pathogenicity in IPA-10 variety bean plants (Phaseolus vulgaris L.), and all were pathogenic. Biological control in vitro was evaluated using eight isolates of Trichoderma spp. and, one of Ulocladium atrum. Chemical control in vitro with fungicides Thiophanate methyl, Iprodione and Carbendazim was also tested. Except U. atrum, all Trichoderma isolates showed antagonistic potential against S. sclerotiorum, where isolate 3601 presented the best performance. Thiophanate methyl chemical control was the most efficient. This fungicide and isolate 3601were compared in vivo in greenhouse. There was statistical difference between the treatments, and the application of fungicide and antagonist before the pathogen was the most efficient approach, reducing the percentage of pathogenicity to 32.94 percent and 37.04 percent, respectively.

Quatro isolados de Sclerotinia sclerotiorum, foram testados quanto à patogenicidade em plantas de feijão, variedade IPA-10 sendo que todos se mostraram patogênicos. Foram avaliados o controle biológico e químico in vitro, utilizando-se oito isolados de Trichoderma e um de Ulocladium atrum, e o controle químico in vitro, com os fungicidas Tiofanato metílico, Iprodione e Carbendazim. Com exceção de U. atrum todos os isolados dos antagonistas mostraram potencial antagônico contra S. sclerotiorum, destacando-se o isolado 3601 como o de melhor desempenho. No controle químico, Tiofanato metílico foi o mais eficiente, sendo este fungicida e o isolado 3601 comparados in vivo em casa-de-vegetação. Foram observadas diferenças estatísticas entre os tratamentos, sendo que a aplicação do fungicida e do antagonista antes da introdução do patógeno foi mais eficiente, com redução do percentual de incidência em 32,94 por cento e 37,04 por cento, respectivamente.

Genetic variability within Fusarium solani specie as revealed by PCR-fingerprinting based on pcr markers

O fungo Fusarium solani (teleomorfo Haematonectria haematococca) apresenta uma expressiva importância na agricultura por ser considerado patógeno para várias culturas de interesse econômico causando doença conhecida por podridão das raízes, além de ser patógeno aos animais e ao homem, provocando nestes últimos, micoses superficiais e sistêmicas. A complexidade associada a sua identificação correta através de métodos tradicionais justifica os esforços de usar marcadores moleculares para caracterização dos isolados. Neste trabalho, três métodos baseados na tecnologia da PCR (um por ribotipagem por PCR e dois por impressão genética por PCR) foram utilizados para investigar a variabilidade molecular de dezoito isolados de F. solani de quatro Estados brasileiros, coletados de diferentes substratos. A análise genética revelou a variabilidade intraespecífica dos isolados de F. solani, sem qualquer correlação para a origem geográfica e substrato. Seu polimorfismo foi observado até mesmo na seqüência conservada do locus do rDNA, e o marcador SPAR (GTG)5 mostrou o mais alto polimorfismo. Em conjunto, estes resultados poderão auxiliar nos estudos da relação entre variabilidade do perfil genético de isolados e os fenótipos de resistência de determinados cultivares às doenças provocadas pelo fungo, orientando programas de melhoramento vegetal.

Cellulase activity of a Lentinula edodes (Berk.) Pegl. strain grown in media containing Carboximetilcellulose or microcrystalline cellulose

Endoglucanase and exocellobiohydrolase produced b Lentinula edodes (Berk.) Pegl. strain thatt was cultivated in carboxymetilcellulose (CMC) or microcrystalline cellulose (Avicel) liquid media. The concentration and type of cellulose influenced the enzyme activity and production. Extra-cellular cellobiase activity was not detected in CMC or Avicel media. This enzyme was detected in mycelial extracts only. With 1.7 percent Avicel liquid medium, the strain did not produce exocellobiohydrolase, but 74 æmol RBBR/mg protein/min was detected with 0.5 percent Avicel. The substitution of Avicel by 0.5 percent CMC reduced this activity. Endoglucanase also had maximum activity in 0.5 percent Avicel medium (approximately 820 UI/mg protein) after 96 h incubation. In supernatants from 0.5 percent CMC, the maximum activity attained was 200 UI/mg protein only