title: Isolation and sequencing of a new glucoamylase gene from an Aspergillus niger aggregate strain (DSM 823) molecularly classified as Aspergillus tubingensis.
abstract: Based on morphological characteristics the taxa included in the Aspergillus aggregate can hardly be differentiated. For that reason the phylogeny of this genus was revised several times as different criteria, from morphological to later molecular, were used. We found, comparing nucleotide sequences of the ITS-region, that the strain Aspergillus niger (DSM 823) which is claimed to be identical to the strains ATCC 10577, IMI 027809, NCTC 7193 and NRRL 2322 can be molecularly classified as Aspergillus tubingensis, exhibiting 100% identity with the A. tubingensis CBS strains 643.92 and 127.49. We amplified, cloned and sequenced a new glucoamylase gene (glaA) from this strain of A. tubingensis (A. niger DSM 823) using primers derived from A. niger glucoamylase G1. The amplified cDNA fragment of 2013 bp contained an open reading frame encoding 648 amino acid residues. The calculated molecular mass of the glucoamylase, deduced from the amino acid sequence, was 68 kDa. The nucleotide sequence of glaA showed 99% similarity with glucoamylases from Aspergillus kawachii and Aspergillus shirousami, whereas the similarity with the glucoamylase G1 from A. niger was 92%
authors.affiliation: Institut für Zelluläre und Molekulare Botanik, Rheinische Friedrich-Wilhelms Universität Bonn, Kirschallee 1, D-53115 Bonn, Germany.
authors.forename: Friederike
authors.initials: F
authors.lastname: Manger-Jacob
authors.forename: Tobias
authors.initials: T
authors.lastname: Müller
authors.forename: Martina
authors.initials: M
authors.lastname: Janssen
authors.forename: Milan
authors.initials: M
authors.lastname: Höfer
authors.forename: Udo
authors.initials: U
authors.lastname: Hölker
mesh_terms: D000595:Amino Acid Sequence; D001234:Aspergillus niger / Q000145:classification* / Q000201:enzymology* / Q000235:genetics; D001483:Base Sequence; D003001:Cloning, Molecular; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D005800:Genes, Fungal; D005087:Glucan 1,4-alpha-Glucosidase / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016366:Open Reading Frames; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer; D005087:Glucan 1,4-alpha-Glucosidase