Electrophoretic comparison of enzymes as a chemotaxonomic aid among Aspergillus taxa: (3) The identity of the xerophilic species A. penicillioides in subgenus Aspergillus section Restricti.

Abstract

The identity of the xerophilic species Aspergillus penicillioides and related taxa has been studied chemotaxonomically using polyacrylamide slab gel electrophoresis. In a dendrogram based on the calculated similarity values of five enzymes, 14 isolates of A. penicillioides in subgenus Aspergillus section Restricti and 28 isolates of related taxa in subgenus Aspergillus formed 22 clusters at a 60% similarity level. A. penicillioides isolates were scattered over the 11 clusters. In the ubiquinone systems, all isolates of A. penicillioides, including IFO 8155 (originally described as A. vitricolae [sic]), had the Q-9 system, which was the same ubiquinone system as Eurotium spp. A case study based on comparisons between the similarity values in enzyme patterns and the homology values in DNA relatedness in subgenus Circumdati section Flavi clearly indicates that Aspergillus isolates at a 60% or greater similarity :level in enzyme patterns are considered to be conspecific. According to this guideline, A. penicillioides isolates are extremely diverse and presumably assigned to several species and we revive the name A. vitricola for IFO 8155 (ex holotype).Further molecular systematic studies are needed to clarify the identity and speciation of A. penicillioides.Aspergillus section Aspergillus Gams et al., associated with Eurotium Edyuillia teleomorphs (the A, glaucus group sensu Thom and Church,26) and and

Genetic relatedness among species in Aspergillus section Clavati as measured by electrophoretic comparison of enzymes, DNA base cmposition, and DNA-DNA hybridization.

“…Clavati. Based on the results of this study and former studies (Tamura et al, 1996(Tamura et al, , 1999, we concluded that species of Aspergillus showing DNA relatedness at 70% or greater are conspecific, as was shown for the yeasts (Kurtzman, 1987).…”

“…At a 60% similarity level, which was adopted by the numerical analysis of enzyme patterns and DNA-DNA hybridization of Aspergillus spp. reported by Tamura et al (1996) and Yamatoya et al (1990), the 15 strains were separated into 9 major clusters. Each cluster corresponds to nine named taxa of Aspergillus: cluster 1 to A. restrictus (xerophilic), cluster 2 to Eurotium chevalieri (xerophilic), cluster 3 to 6 strains of A. clavatus, cluster 4 to A. clavatonanicus, cluster 5 to 2 strains of A. giganteus, cluster 6 to A. brunneo-uniseriatus in sect.…”

“…They have concluded that A. flavus, A. oryzae, A. parasiticus, and A. sojae represent a single species. Comparative studies by Tamura et al (1996) and Yamatoya et al (1990) suggested that a good correlation exists between enzyme patterns and DNA relatedness among species of Aspergillus sect. Flavi.…”

“…Four enzymes were examined in this study: glucose 6-phosphate dehydrogenase (G6PDH; NADP-dependent; EC 1.1.1.49), lactate dehydrogenase (LDH; NAD-dependent; EC 1.1.1.27), malate dehydrogenase (MDH; NAD-dependent; EC 1.1.1.37), and glutamate dehydrogenase (GDH; NADP-dependent; EC 1.4.1.4). These enzymes were chosen because they are effective in the differentiation of the species of Aspergillus (Matsuda et al, 1992;Sugiyama and Yamatoya, 1990;Tamura et al, 1996;Yamatoya et al, 1990).…”

Identity of the xerophilic species <i>Aspergillus penicillioides</i>: Integrated analysis of the genotypic and phenotypic characters

“…A. penicillioides strains were scattered over 11 clusters and exhibited their great divergence. Among A. penicillioides strains, IFO 8155 (originally described as A. vitricolae [sic]) did not group with A. penicillioides NRRL 4548 (ex neotype), but were placed in the cluster 15 with three strains of A. penicillioides (cf., Tamura et al, 1996). They concluded that A. penicillioides strains, all having Q-9 as the major ubiquinone system, are genealogically diverse and presumably represent several species.…”