The β-1,3-Exoglucanase GeneexgA(exg1) ofAspergillus oryzaeIs Required to Catabolize Extracellular Glucan, and Is Induced in Growth on a Solid Surface

Tamano, Koichi; Satoh, Yuki; Ishii, Tomoko; Terabayashi, Yasunobu; Ohtaki, Shinsaku; Sano, Motoaki; Takahashi, Tadashi; Koyama, Yasuji; Mizutani, Osamu; Abe, Keietsu; Machida, Masayuki

doi:10.1271/bbb.60591

Cited by 49 publications

(22 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Deletion of the exo-b-1,3-glucanase exgA in A. oryzae reduced the growth rate on b-1,3-glucan and the sporulation efficiency when grown on either b-1,3 or b-1,6-glucan. In the wild-type strain, expression of this gene was induced upon starvation and during growth on hydrophobic, solid surfaces (Tamano et al, 2007), consistent with conditions in which sporulation occurs. Induction of b-1,3-glucanotransferases gelG and gelA in the aerial structures shows that not only hydrolysis but also remodelling of b-1,3-glucan is important during sporulation.…”

Section: J M Van Munster and Otherssupporting

confidence: 56%

Chitinases CtcB and CfcI modify the cell wall in sporulating aerial mycelium of Aspergillus niger

et al. 2013

View full text Add to dashboard Cite

Sporulation is an essential part of the life cycle of the industrially important filamentous fungus Aspergillus niger. The formation of conidiophores, spore-bearing structures, requires remodelling of the fungal cell wall, as demonstrated by the differences in carbohydrate composition of cell walls of vegetative mycelium and spores. Glycoside hydrolases that are involved in this process have so far remained unidentified. Using transcriptome analysis, we have identified genes encoding putative cell-wall-modifying proteins with enhanced expression in sporulating aerial mycelium compared to vegetative mycelium. Among the most strongly induced genes were those encoding a protein consisting of a putative chitin binding module (CBM14) and the chitinolytic enzymes NagA, CfcI and CtcB. Reporter studies showed that the N-acetyl-b-hexosaminidase gene nagA was expressed both in vegetative hyphae and in aerial structures (aerial hyphae, conidiophores and conidia) upon starvation. In contrast, promoter activities of the chitinase genes ctcB and cfcI were specifically localized in the conidiophores and conidia. CtcB is an endochitinase and CfcI releases monomers from chitin oligosaccharides: together these enzymes have the potential to degrade chitin of the fungal cell wall. Inactivation of both the cfcI and ctcB genes affected neither radial growth rate, nor formation and germination of spores. The amount of chitin in the spore walls of a DcfcIDctcB double deletion strain, however, was significantly increased compared with the wild-type, thus indicating that CfcI and CtcB indeed modify the A. niger cell walls during sporulation. These novel insights in the sporulation process in aspergilli are of strong scientific relevance, and also may aid industrial strain engineering.

show abstract

Section: J M Van Munster and Otherssupporting

confidence: 56%

Chitinases CtcB and CfcI modify the cell wall in sporulating aerial mycelium of Aspergillus niger

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Likewise, A. oryzae acid protease-encoding gene pepA and the transcription factor encoded by the gene brlA that regulates sporulation in this species are only expressed in solid-state fermentation [87,88]. Also, in A. oryzae, exgA expression was induced in growth on solid surfaces and a combination of poor nutrition and mycelia attachment to a hydrophobic solid surface appears to be the inducing factors [89]. Polarized growth that is seen during SSF of A. oryzae may depend on 29 identified genes which are expressed at higher levels; 6 encode proteins that are functionally related to polarized growth, 4 encode products known to be involved in morphogenesis, 3 code for proteins related to cell wall composition, and 9 encode novel proteins [90].…”

Section: Molecular Biologymentioning

confidence: 99%

Recent Advances on Filamentous Fungal Biofilms for Industrial Uses

Gutiérrez-Correa

Ludeña

Ramage

et al. 2012

Appl Biochem Biotechnol

View full text Add to dashboard Cite

Industrial enzymes are produced by submerged fermentation (SF) and by solid-state fermentation (SSF) to a lesser extent. Although SSF has several advantages, its scale-up is difficult. The role of physiological and genetic properties of microorganisms growing attached to surfaces could explain the advantages of SSF. Filamentous fungi are naturally adapted to growth on surfaces and in these conditions they show a particular physiological behavior which is different from that in SF; thus, they also form biofilms. Fermentation by filamentous fungal biofilms (FFB) is a homogeneous production system within a liquid environment based on the infrastructure of the SF process with the productive efficiency of the SSF. Enzyme production levels of FFB are much higher than those obtained in SF and they are also amenable of mixed fungal cultivation. Transcriptomic and proteomic tools are used to uncover the fundamental biological issues behind FFB. Several genes encoding cellulolytic enzymes are either differentially expressed or overexpressed in FFB. Moreover, our proteomic studies of Aspergillus niger biofilms compared to SF indicate that many intracellular proteins are either differentially expressed or overexpressed. Clinically important fungi like A. fumigatus also form biofilms when they infect lungs and recent studies demonstrate same gene expression features. These results support our hypothesis of cell adhesion and its role in the new schemes for improved fermentative production of industrial enzymes.

show abstract

“…To analyze the laeA function in A. oryzae, ÁLaeA was created by a procedure described by Tamano et al (2007).…”

mentioning

confidence: 99%

Aspergillus oryzae laeARegulates Kojic Acid Synthesis Genes

Oda

Kobayashi

Ohashi

et al. 2011

Bioscience, Biotechnology, and Biochemistry

Self Cite

View full text Add to dashboard Cite

The β-1,3-Exoglucanase GeneexgA(exg1) ofAspergillus oryzaeIs Required to Catabolize Extracellular Glucan, and Is Induced in Growth on a Solid Surface

Cited by 49 publications

References 27 publications

Chitinases CtcB and CfcI modify the cell wall in sporulating aerial mycelium of Aspergillus niger

Chitinases CtcB and CfcI modify the cell wall in sporulating aerial mycelium of Aspergillus niger

Recent Advances on Filamentous Fungal Biofilms for Industrial Uses

Aspergillus oryzae laeARegulates Kojic Acid Synthesis Genes

Contact Info

Product

Resources

About