Extensive sampling of basidiomycete genomes demonstrates inadequacy of the white-rot/brown-rot paradigm for wood decay fungi.

Basidiomycota (basidiomycetes) make up 32% of the described fungi and include most wood-decaying species, as well as pathogens and mutualistic symbionts. Wood-decaying basidiomycetes have typically been classified as either white rot or brown rot, based on the ability (in white rot only) to degrade lignin along with cellulose and hemicellulose. Prior genomic comparisons suggested that the two decay modes can be distinguished based on the presence or absence of ligninolytic class II peroxidases (PODs), as well as the abundance of enzymes acting directly on crystalline cellulose (reduced in brown rot).

Factors contributing to the recalcitrance of herbaceous dicotyledons (forbs) to enzymatic deconstruction.

Background: Many different feedstocks are under consideration for the practical production of biofuels from lignocellulosic materials. The best choice under any particular combination of economic, agronomic, and environmental conditions depends on multiple factors. The use of old fields, restored prairie, or marginal lands to grow biofuel feedstocks offers several potential benefits including minimal agronomic inputs, reduced competition with food production, and high biodiversity.

Enhancement of fermentable sugar yields by α-xylosidase supplementation of commercial cellulases.

Background: Although α-linked xylose is a major constituent of the hemicelluloses of land plants, few secreted α-xylosidases have been described from fungi or bacteria. AxlA of Aspergillus niger is a secreted α-xylosidase that was earlier shown to promote the release of free glucose (Glc) and xylose (Xyl) from substrates containing α-linked xylose, including isoprimeverose (IP), the heptasaccharide subunit of pea xyloglucan (XG), and tamarind XG.

Results: The utility of AxlA for enhancing release of free Glc and Xyl in combination with commercial enzyme cocktails from dicotyledonous and monocotyledonous plants was examined.

A highly thermoactive and salt-tolerant α-amylase isolated from a pilot-plant biogas reactor.

Aiming at the isolation of novel enzymes from previously uncultured thermophilic microorganisms, a metagenome library was constructed from DNA isolated from a pilot-plant biogas reactor operating at 55 °C. The library was screened for starch-degrading enzymes, and one active clone was found. An open reading frame of 1,461 bp encoding an α-amylase from an uncultured organism was identified.

A novel thermostable and glucose-tolerant β-glucosidase from Fervidobacterium islandicum.

An open reading frame (ORF) encoding the enzyme β-glucosidase from the extremely thermophilic bacterium Fervidobacterium islandicum has been identified, cloned and sequenced. The bgl1A gene was cloned in a pET-Blue1 vector and transformed in Escherichia coli, resulting in high-level expression of β-glucosidase FiBgl1A that was purified to homogeneity in a two-step purification. FiBgl1A is composed of 459 amino acid residues and showed high homology to glycoside hydrolase family 1 proteins.

Gluconeotrehalose is the principal organic solute in the psychrotolerant bacterium Carnobacterium strain 17-4.

A high proportion of microorganisms that colonise cold environments originate from marine sites; hence, they must combine adaptation to low temperature with osmoregulation. However, little or nothing is known about the nature of compatible solutes used by cold-adapted organisms to balance the osmotic pressure of the external medium. We studied the intracellular accumulation of small organic solutes in the Arctic isolate Carnobacterium strain 17-4 as a function of the growth temperature and the NaCl concentration in the medium.