Rapid differentiation of four related species of Koji molds by agarose gel electrophoresis of genomic DNA digested with SmaI restriction enzyme.

Gomi, Katsuya; Tanaka, Akio; Iimura, Yuzuru; Takahashi, Koichi

doi:10.2323/jgam.35.225

Cited by 25 publications

(6 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A. toxicarius was suggested to be conspecific with A. parasiticus by Kozakiewicz (1989), which view is supported by the sequence data. Although both morphological and molecular techniques have been successfully used to distinguish A. parasiticus and A. sojae isolates (Gomi et al, 1989;Murakami et al, 1982;Yuan et al, 1995), these form a monophyletic clade together with A. toxicarius (Figs. 2 and 3).…”

Section: Resultsmentioning

confidence: 99%

Evolutionary relationships within Aspergillus section Flavi based on sequences of the intergenic transcribed spacer regions and the 5.8S rRNA gene.

Rigó

Varga

Töth

et al. 2002

J. Gen. Appl. Microbiol.

View full text Add to dashboard Cite

Section: Resultsmentioning

confidence: 99%

Evolutionary relationships within Aspergillus section Flavi based on sequences of the intergenic transcribed spacer regions and the 5.8S rRNA gene.

Rigó

Varga

Töth

et al. 2002

J. Gen. Appl. Microbiol.

View full text Add to dashboard Cite

“…Molecular recognition of species by using the V7 to V9 variable domains of 18S rRNA was performed by Melchers et al (345). RFLP by itself or with Southern blot analysis of mtDNA or nDNA or both has been used to indicate relationships among Aspergillus isolates (103,194,281,287). Numerical taxonomic studies based on combinations of different types of biochemical, physiological, and morphological characteristics have also been used (65,66,425).…”

Section: Plectomycetesmentioning

confidence: 99%

Developments in Fungal Taxonomy

1999

View full text Add to dashboard Cite

SUMMARY Fungal infections, especially those caused by opportunistic species, have become substantially more common in recent decades. Numerous species cause human infections, and several new human pathogens are discovered yearly. This situation has created an increasing interest in fungal taxonomy and has led to the development of new methods and approaches to fungal biosystematics which have promoted important practical advances in identification procedures. However, the significance of some data provided by the new approaches is still unclear, and results drawn from such studies may even increase nomenclatural confusion. Analyses of rRNA and rDNA sequences constitute an important complement of the morphological criteria needed to allow clinical fungi to be more easily identified and placed on a single phylogenetic tree. Most of the pathogenic fungi so far described belong to the kingdom Fungi; two belong to the kingdom Chromista. Within the Fungi, they are distributed in three phyla and in 15 orders (Pneumocystidales, Saccharomycetales, Dothideales, Sordariales, Onygenales, Eurotiales, Hypocreales, Ophiostomatales, Microascales, Tremellales, Poriales, Stereales, Agaricales, Schizophyllales, and Ustilaginales).

show abstract

“…These fungi belong to the Aspergillus section Flavi, which includes Aspergillus flavus and Aspergillus parasiticus, some of which produce the procarcinogen aflatoxin. It is thought that A. oryzae and A. sojae are taxonomically differentiated from A. flavus and A. parasiticus, respectively (20,21,23,35,37). It has been demonstrated that most of the 25 identified genes clustered within a specific 70-kb region of the fungal genome are involved in aflatoxin biosynthesis (reviewed in references 3, 13, 22, 40, 45, 49, and 54).…”

mentioning

confidence: 99%

Molecular Analysis of an Inactive Aflatoxin Biosynthesis Gene Cluster in Aspergillus oryzae RIB Strains

Tominaga

Lee

Hayashi

et al. 2006

Appl Environ Microbiol

120

View full text Add to dashboard Cite

To help assess the potential for aflatoxin production by Aspergillus oryzae, the structure of an aflatoxin biosynthesis gene homolog cluster in A. oryzae RIB 40 was analyzed. Although most genes in the corresponding cluster exhibited from 97 to 99% similarity to those of Aspergillus flavus, three genes shared 93% similarity or less. A 257-bp deletion in the aflT region, a frameshift mutation in norA, and a base pair substitution in verA were found in A. oryzae RIB 40. In the aflR promoter, two substitutions were found in one of the three putative AreA binding sites and in the FacB binding site. PCR primers were designed to amplify homologs of aflT, nor-1, aflR, norA, avnA, verB, and vbs and were used to detect these genes in 210 A. oryzae strains. Based on the PCR results, the A. oryzae RIB strains were classified into three groups, although most of them fell into two of the groups. Group 1, in which amplification of all seven genes was confirmed, contained 122 RIB strains (58.1% of examined strains), including RIB 40. Seventy-seven strains (36.7%) belonged to group 2, characterized by having only vbs, verB, and avnA in half of the cluster. Although slight expression of aflR was detected by reverse transcription-PCR in some group 1 strains, including RIB 40, other genes (avnA, vbs, verB, and omtA) related to aflatoxin production were not detected. aflR was not detected in group 2 strains by Southern analysis.Koji molds, Aspergillus oryzae and Aspergillus sojae, have traditionally been used in the brewing industry for the production of sake, miso, and soy sauce. A history of safety (1) and nonproductivity of aflatoxin is well established for industrial strains, and A. oryzae is considered "generally recognized as safe" by the U.S. Food and Drug Administration (41). These fungi belong to the Aspergillus section Flavi, which includes Aspergillus flavus and Aspergillus parasiticus, some of which produce the procarcinogen aflatoxin. It is thought that A. oryzae and A. sojae are taxonomically differentiated from A. flavus and A. parasiticus, respectively (20, 21, 23, 35, 37). It has been demonstrated that most of the 25 identified genes clustered within a specific 70-kb region of the fungal genome are involved in aflatoxin biosynthesis (reviewed in references 3, 13, 22, 40, 45, 49, and 54). Among them, the aflR gene is known to encode a major transcriptional regulator of aflatoxin biosynthesis genes (6,9,19,28,47,55). AflR binds to the consensus sequence 5Ј-TCGN 5 CGR-3Ј (16) found in the promoters of most of the aflatoxin biosynthesis genes (54), including aflR (14, 17). Putative binding sites (14, 17) for the transcription factors AreA (10, 34, 36), PacC (18), and FacB (43) have been identified in the aflR promoter.For A. sojae, several studies (30, 31, 42) have suggested an inability to produce aflatoxin, because mutations have been found in the aflR homolog (46). On the other hand, Kusumoto et al. (25) reported that 39 strains of A. oryzae could be classified into three groups based on fragment analysis by a lo...

show abstract

Rapid differentiation of four related species of Koji molds by agarose gel electrophoresis of genomic DNA digested with SmaI restriction enzyme.

Cited by 25 publications

References 10 publications

Evolutionary relationships within Aspergillus section Flavi based on sequences of the intergenic transcribed spacer regions and the 5.8S rRNA gene.

Evolutionary relationships within Aspergillus section Flavi based on sequences of the intergenic transcribed spacer regions and the 5.8S rRNA gene.

Developments in Fungal Taxonomy

Molecular Analysis of an Inactive Aflatoxin Biosynthesis Gene Cluster in Aspergillus oryzae RIB Strains

Contact Info

Product

Resources

About