Mycology Research Today is a free monthly online journal that collates and summarizes the latest research about Mycology, including details on fungi, diseases, identification, microscopy.

Two novel thermostable chitinase genes from thermophilic fungi: Cloning, expression and characterization.

Li AN, Yu K, Liu HQ, Zhang J, Li H, Li DC

Department of Environmental Biology, Shandong Agricultural University, Taian, Shandong 271018, China.

Two chitinase genes, Tachit1 from Thermoascus aurantiacus var. levisporus and Ctchit1 from Chaetomium thermophilum were isolated. Tachit1 and Ctchit1 encode putative single-domain proteins (TaCHIT1 and CtCHIT1) of 399 and 402 amino acid residues, respectively. The catalytic domains of TaCHIT1 and CtCHIT1 are similar to those of other fungal chitinases in family 18 of glycosyl hydrolases. TaCHIT1 and CtCHIT1 have a molecular weight of about 48.4 and 47.3kDa, respectively when produced in recombinant Pichia pastoris. The enzymes exhibited optimum catalytic activity at pH 8.0 and 50 degrees C for TaCHIT1 and at pH 5.5 and 60 degrees C for CtCHIT1. TaCHIT1 retained 95.3% of its activity after 60min at 50 degrees C. CtCHIT1 was stable at 50 degrees C and retained 96.7% of its activity after 60min incubation at 60 degrees C. The TaCHIT1 and CtCHIT1 produced Glc-NAc2 as the major product, when colloidal chitin was used as the substrate. The enzyme could not hydrolyze pNp-(GlcNAc), but hydrolyzed colloidal chitin, powdery chitin and chitosan. These features make these proteins potentially useful for applications requiring chitin hydrolysis at elevated temperatures.

Published 12 March 2010 in Bioresour Technol.
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Articles on Mycology published 11 March 2010:

Population dynamics and identification of endophytic bacteria antagonistic toward plant-pathogenic fungi in cotton root.   Microb Ecol, 59(2): 344-56.

The antagonistic potentials of endophytic bacteria isolated from the roots of six cotton cultivars at different developmental stages were determined in vitro toward three pathogens: Verticillium dahliae Kleb V107 and V396 and Fusarium oxysporum f.sp. vasinfectum (F108). The populations of antagonistic endophytic bacteria (AEB) toward V107, V396, and F108 at the flowering and maturation stages were significantly higher than those at the seedling stage were. More AEB were found to be antagonistic ... [Abstract] [Full-text]

Comparative analysis of expressed sequence tags from the white-rot fungi (Phanerochaete chrysosporium).   Mol Cells, 29(2): 131-44.

Comprehensive analysis of the transcriptome of the P. chrysosporium is a useful approach to improve our understanding of its special and unique enzyme system and fungal evolution in molecular and industrial aspects. In order to unveil the functional diversity of this white-rot fungus in gene level and the expression patterns of its genes, in this study we carried out sequencing and annotation of 4,917 P. chrysosporium expressed sequence tags (ESTs). Through our bioinformatic ESTs analysis, we ... [Abstract] [Full-text]

Identification and characterization of Tc1/mariner-like DNA transposons in genomes of the pathogenic fungi of the Paracoccidioides species complex.   BMC Genomics, 11: 130.

ABSTRACT: BACKGROUND: Paracoccidioides brasiliensis (Eukaryota, Fungi, Ascomycota) is a thermodimorphic fungus, the etiological agent of paracoccidioidomycosis, the most important systemic mycoses in Latin America. Three isolates corresponding to distinct phylogenetic lineages of the Paracoccidioides species complex had their genomes sequenced. In this study the identification and characterization of class II transposable elements in the genomes of these fungi was carried out. RESULTS: A ... [Abstract] [Full-text]

Production of Cellulolytic Enzymes by Fungi Acrophialophora nainiana and Ceratocystis paradoxa Using Different Carbon Sources.   Appl Biochem Biotechnol, 161(1): 448-54.

Although a number of filamentous fungi, such as Trichoderma and Aspergillus, are well known as producers of cellulases, xylanases, and accessory cellulolytic enzymes, the search for new strains and new enzymes has become a priority with the increase in diversity of biomass sources. Moreover, according to the type of pretreatment applied, biomass of the same type may require different enzyme blends to be efficiently hydrolyzed. This study evaluated cellulases, xylanases, and beta-glucosidases ... [Abstract] [Full-text]

An evolutionary perspective on morphological and ecological characters in the mushroom family Inocybaceae (Agaricomycotina, Fungi).   Mol Phylogenet Evol.

Inocybaceae is one of the larger families among the gilled mushrooms (Agaricales) but their morphology-based taxonomy is still not fully settled considering molecular-based phylogenetic insights. Here we investigate the evolution of five morphological and four ecological characters using ancestral state reconstruction methods. All the morphological characters are correlated with the phylogeny, but we find spore shape and presence of cortina, to have the greatest taxonomic potential, as they are ... [Abstract] [Full-text]

Evaluation of holocellulase production by plant-degrading fungi grown on agro-industrial residues.   Biodegradation.

Agaricus brasiliensis CS1, Pleurotus ostreatus H1 and Aspergillus flavus produced holocellulases when grown in solid and submerged liquid cultures containing agro-industrial residues, including sugar cane bagasse and dirty cotton residue, as substrates. These isolates proved to be efficient producers of holocellulases under the conditions used in this screening. Bromatological analysis of agro-industrial residues showed differences in protein, fiber, hemicellulose, cellulose and lignin content. ... [Abstract] [Full-text]

Endophytic fungi diversity of aquatic/riparian plants and their antifungal activity in vitro.   J Microbiol, 48(1): 1-6.

Two hundred and fourteen endophytic fungi were isolated from 500 segments of aquatic/riparian plants Ottelia acuminata, Myriophyllum verticillatum, Equisetum arvense, Cardamine multijuga, and Impatiens chinensis. They were identified to 31 taxa in which Cladosporium, Fusarium, and Geotrichum were the dominant genera. Among all isolates, 169 (79%) were anamorphic fungi, 1 (0.5%) was an teleomorphic ascomycete and 44 (21%) were sterile mycelia. There were significant differences in the ... [Abstract] [Full-text]

Disruption of root carbon transport into forest humus stimulates fungal opportunists at the expense of mycorrhizal fungi.   ISME J.

Ectomycorrhizal fungi dominate the humus layers of boreal forests. They depend on carbohydrates that are translocated through roots, via fungal mycelium to microsites in the soil, wherein they forage for nutrients. Mycorrhizal fungi are therefore sensitive to disruptive disturbances that may restrict their carbon supply. By disrupting root connections, we induced a sudden decline in mycorrhizal mycelial abundance and studied the consequent effects on growth and activity of free living, ... [Abstract] [Full-text]

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