Active substances against trypomastigote forms of Trypanosoma cruzi and microorganisms are produced in sequence by Talaromyces flavus. (1/18)

The conditions for the sequential production of antibiotic activity by Talaromyces flavus were determined. The highest level of activity against Trypanosoma cruzi was obtained from the aqueous extract of the Czapeck's fermentative culture after 48 hours, with lysis of 97.58% of the trypomastigote forms of Trypanosoma cruzi (red blood cells remained normal). The antimicrobial activity was detected in the extracts of fermentative cultures from different media just after 144 hours of incubation. Maximum activities against Micrococcus luteus, Staphylococcus aureus and Candida albicans were present in chloroform, butanolic and water extracts, in this order, when Talaromyces flavus was cultivated at pH 5.0. The minimal inhibitory concentration (MIC) of extracts of Takeuchi's cultures were determined.  (+info)

Mitochondrial malate dehydrogenase from the thermophilic, filamentous fungus Talaromyces emersonii. (2/18)

Mitochondrial malate dehydrogenase (m-MDH; EC 1.1.1.37), from mycelial extracts of the thermophilic, aerobic fungus Talaromyces emersonii, was purified to homogeneity by sequential hydrophobic interaction and biospecific affinity chromatography steps. Native m-MDH was a dimer with an apparent monomer mass of 35 kDa and was most active at pH 7.5 and 52 degrees C in the oxaloacetate reductase direction. Substrate specificity and kinetic studies demonstrated the strict specificity of this enzyme, and its closer similarity to vertebrate m-MDHs than homologs from invertebrate or mesophilic fungal sources. The full-length m-MDH gene and its corresponding cDNA were cloned using degenerate primers derived from the N-terminal amino acid sequence of the native protein and multiple sequence alignments from conserved regions of other m-MDH genes. The m-MDH gene is the first oxidoreductase gene cloned from T. emersonii and is the first full-length m-MDH gene isolated from a filamentous fungal species and a thermophilic eukaryote. Recombinant m-MDH was expressed in Escherichia coli, as a His-tagged protein and was purified to apparent homogeneity by metal chelate chromatography on an Ni2+-nitrilotriacetic acid matrix, at a yield of 250 mg pure protein per liter of culture. The recombinant enzyme behaved as a dimer under nondenaturing conditions. Expression of the recombinant protein was confirmed by Western blot analysis using an antibody against the His-tag. Thermal stability studies were performed with the recombinant protein to investigate if results were consistent with those obtained for the native enzyme.  (+info)

Three-dimensional structure of a thermostable native cellobiohydrolase, CBH IB, and molecular characterization of the cel7 gene from the filamentous fungus, Talaromyces emersonii. (3/18)

The X-ray structure of native cellobiohydrolase IB (CBH IB) from the filamentous fungus Talaromyces emersonii, PDB 1Q9H, was solved to 2.4 A by molecular replacement. 1Q9H is a glycoprotein that consists of a large, single domain with dimensions of approximately 60 A x 40 A x 50 A and an overall beta-sandwich structure, the characteristic fold of Family 7 glycosyl hydrolases (GH7). It is the first structure of a native glycoprotein and cellulase from this thermophilic eukaryote. The long cellulose-binding tunnel seen in GH7 Cel7A from Trichoderma reesei is conserved in 1Q9H, as are the catalytic residues. As a result of deletions and other changes in loop regions, the binding and catalytic properties of T. emersonii 1Q9H are different. The gene (cel7) encoding CBH IB was isolated from T. emersonii and expressed heterologously with an N-terminal polyHis-tag, in Escherichia coli. The deduced amino acid sequence of cel7 is homologous to fungal cellobiohydrolases in GH7. The recombinant cellobiohydrolase was virtually inactive against methylumberiferyl-cellobioside and chloronitrophenyl-lactoside, but partial activity could be restored after refolding of the urea-denatured enzyme. Profiles of cel7 expression in T. emersonii, investigated by Northern blot analysis, revealed that expression is regulated at the transcriptional level. Putative regulatory element consensus sequences for cellulase transcription factors have been identified in the upstream region of the cel7 genomic sequence.  (+info)

High viscosity and anisotropy characterize the cytoplasm of fungal dormant stress-resistant spores. (4/18)

Ascospores of the fungus Talaromyces macrosporus are dormant and extremely stress resistant, whereas fungal conidia--the main airborne vehicles of distribution--are not. Here, physical parameters of the cytoplasm of these types of spores were compared. Cytoplasmic viscosity and level of anisotropy as judged by spin probe studies (electron spin resonance) were extremely high in dormant ascospores and during early germination and decreased only partly after trehalose degradation and glucose efflux. Upon prosilition (ejection of the spore), these parameters fell sharply to values characteristic of vegetative cells. These changes occurred without major volume changes that suggest dramatic changes in cytoplasmic organization. Azide reversibly inhibited prosilition as well as the decline in cytoplasmic parameters. No organelle structures were observed in etched, cryoplaned specimens of ascospores by low-temperature scanning electron microscopy (LTSEM), confirming the high cytoplasmic viscosity. However, cell structures became visible upon prosilition, indicating reduced viscosity. The viscosity of fresh conidia of different Penicillium species was lower, namely, 3.5 to 4.8 cP, than that of ascospores, near 15 cP. In addition the level of anisotropic motion was markedly lower in these cells (h(0)/h(+1) = 1.16 versus 1.4). This was confirmed by LTSEM images showing cell structures. The decline of cytoplasmic viscosity in conidia during germination was linked with a gradual increase in cell volume. These data show that mechanisms of cytoplasm conservation during germination differ markedly between ascospores and conidia.  (+info)

Inhibition of a secreted glutamic peptidase prevents growth of the fungus Talaromyces emersonii. (5/18)

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Characterization of a multimeric, eukaryotic prolyl aminopeptidase: an inducible and highly specific intracellular peptidase from the non-pathogenic fungus Talaromyces emersonii. (6/18)

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Heat activation of Neosartorya and Talaromyces ascospores and enhancement by organic acids. (7/18)

Neosartorya and Talaromyces are typical fungi capable of producing heat resistant ascospores responsible for the spoilage of processed fruit products. In this study, the heat activation rates of Neosartorya and Talaromyces ascospores were investigated in several suspending media at various heating temperatures. Ascospores were dispersed in pH 3.5 McIlvain buffer, organic acid/alcohol-supplemented McIlvain buffer and grape juice (pH 3.5, 5.0 degrees Brix) prior to heat treatments. In McIlvain buffer, the number of germinating ascospores increased logarithmically with longer exposure to heating at an test temperatures. Heat activation rates (k values) accelerated with increasing temperature. The calculated activation energy (Ea) values were similar among ascospores from the same genus, but the Ea of the test Neosartorya spp. were greater than that of the test Talaromyces spp. Greater k values were calculated from acetate-supplemented McIlvain buffer and grape juice. Similarly, normal- and branched-chain fatty acids were shown to enhance the heat activation rate of the ascospores in McIlvain buffer systems. These results could assist the food industry in designing adequate thermal processes for food products against the heat resistant fungi.  (+info)

Expression of Talaromyces emersonii cellobiohydrolase Cel7A in Saccharomyces cerevisiae and rational mutagenesis to improve its thermostability and activity. (8/18)

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