Oxido-reductive metabolism of L-arabinose and D-galactose in filamentous fungi: Metabolic crosstalk versus specific enzymes

Research output: Chapter in Book/Report/Conference proceedingConference abstract in proceedingsScientific

Abstract

L-arabinose, the second most abundant pentose sugar, is used as a carbon source by a variety of microorganisms living on decaying plant material. Fungal microorganisms catabolize L-arabinose through an oxido-reductive pathway. We have identified two missing links in the pathway, L-arabinose and L-xylulose reductases in A.niger. D-galactose is a relatively rare hexose sugar in the plant cell wall mainly found in galactoglucomannan. There are three pathways indentified in fungi for D-galactose degradation; 1) the Leloir pathway in which
D-galactose is phosphorylated, 2) the oxidative pathway which starts by an extracellular galactose oxidase reaction, and 3) a recently proposed oxido-reductive pathway which resembles the pathway for L-arabinose catabolism. It has been suggested in T. reesei and A. nidulans the oxido-reductive D-galactose pathway employs the enzymes from the L-arabinose pathway. It starts with the conversion of D-galactose to D-galactitol, probably carried by the xylose/arabinose reductase. The second step is catalyzed by L-arabitol dehydrogenase and the product of the reaction is an unusual sugar L-xylo-3-hexulose. We have identified the L-xylulose reductase possesses the activity
with this intermediate which is converted to D-sorbitol. Finally, D-sorbitol is oxidized to D-fructose, which enters glycolysis. We have studied the pathway in A. niger and uncovered a more complex picture. Apart from showing the possible involvement of the L-arabinose pathway enzymes, we identified two dehydrogenases specifically induced on D-galactose, suggesting that A. niger might have specific genes for catabolism of D-galactose rather than using metabolic crosstalk suggested for T. reesei and A. nidulans.
Original languageEnglish
Title of host publication26th Fungal Genetics Conference
Subtitle of host publicationProgram and Abstracts
Publication statusPublished - 2011
MoE publication typeNot Eligible
Event26th Fungal Genetics Conference - Asilomar, United States
Duration: 15 Mar 201120 Mar 2011

Publication series

NameFungal Genetics Reports
PublisherThe Genetics Society of America
NumberSupplement
Volume58

Conference

Conference26th Fungal Genetics Conference
CountryUnited States
CityAsilomar
Period15/03/1120/03/11

Fingerprint

arabinose
galactose
fungi
metabolism
enzymes
xylulose
sorbitol
sugars
galactitol
microorganisms
pentoses
hexoses
glycolysis
xylose
fructose
cell walls
degradation
carbon

Cite this

Mojzita, D., Koivistoinen, O., Vuoristo, K., Ruohonen, L., Penttilä, M., & Richard, P. (2011). Oxido-reductive metabolism of L-arabinose and D-galactose in filamentous fungi: Metabolic crosstalk versus specific enzymes. In 26th Fungal Genetics Conference: Program and Abstracts [328] Fungal Genetics Reports, No. Supplement, Vol.. 58
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author = "Dominik Mojzita and Outi Koivistoinen and Kiira Vuoristo and Laura Ruohonen and Merja Penttil{\"a} and Peter Richard",
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Mojzita, D, Koivistoinen, O, Vuoristo, K, Ruohonen, L, Penttilä, M & Richard, P 2011, Oxido-reductive metabolism of L-arabinose and D-galactose in filamentous fungi: Metabolic crosstalk versus specific enzymes. in 26th Fungal Genetics Conference: Program and Abstracts., 328, Fungal Genetics Reports, no. Supplement, vol. 58, 26th Fungal Genetics Conference, Asilomar, United States, 15/03/11.

Oxido-reductive metabolism of L-arabinose and D-galactose in filamentous fungi: Metabolic crosstalk versus specific enzymes. / Mojzita, Dominik (Corresponding author); Koivistoinen, Outi; Vuoristo, Kiira; Ruohonen, Laura; Penttilä, Merja; Richard, Peter.

26th Fungal Genetics Conference: Program and Abstracts. 2011. 328 (Fungal Genetics Reports; No. Supplement, Vol. 58).

Research output: Chapter in Book/Report/Conference proceedingConference abstract in proceedingsScientific

TY - CHAP

T1 - Oxido-reductive metabolism of L-arabinose and D-galactose in filamentous fungi: Metabolic crosstalk versus specific enzymes

AU - Mojzita, Dominik

AU - Koivistoinen, Outi

AU - Vuoristo, Kiira

AU - Ruohonen, Laura

AU - Penttilä, Merja

AU - Richard, Peter

N1 - CA2: TK402 CA2: TK400

PY - 2011

Y1 - 2011

N2 - L-arabinose, the second most abundant pentose sugar, is used as a carbon source by a variety of microorganisms living on decaying plant material. Fungal microorganisms catabolize L-arabinose through an oxido-reductive pathway. We have identified two missing links in the pathway, L-arabinose and L-xylulose reductases in A.niger. D-galactose is a relatively rare hexose sugar in the plant cell wall mainly found in galactoglucomannan. There are three pathways indentified in fungi for D-galactose degradation; 1) the Leloir pathway in whichD-galactose is phosphorylated, 2) the oxidative pathway which starts by an extracellular galactose oxidase reaction, and 3) a recently proposed oxido-reductive pathway which resembles the pathway for L-arabinose catabolism. It has been suggested in T. reesei and A. nidulans the oxido-reductive D-galactose pathway employs the enzymes from the L-arabinose pathway. It starts with the conversion of D-galactose to D-galactitol, probably carried by the xylose/arabinose reductase. The second step is catalyzed by L-arabitol dehydrogenase and the product of the reaction is an unusual sugar L-xylo-3-hexulose. We have identified the L-xylulose reductase possesses the activitywith this intermediate which is converted to D-sorbitol. Finally, D-sorbitol is oxidized to D-fructose, which enters glycolysis. We have studied the pathway in A. niger and uncovered a more complex picture. Apart from showing the possible involvement of the L-arabinose pathway enzymes, we identified two dehydrogenases specifically induced on D-galactose, suggesting that A. niger might have specific genes for catabolism of D-galactose rather than using metabolic crosstalk suggested for T. reesei and A. nidulans.

AB - L-arabinose, the second most abundant pentose sugar, is used as a carbon source by a variety of microorganisms living on decaying plant material. Fungal microorganisms catabolize L-arabinose through an oxido-reductive pathway. We have identified two missing links in the pathway, L-arabinose and L-xylulose reductases in A.niger. D-galactose is a relatively rare hexose sugar in the plant cell wall mainly found in galactoglucomannan. There are three pathways indentified in fungi for D-galactose degradation; 1) the Leloir pathway in whichD-galactose is phosphorylated, 2) the oxidative pathway which starts by an extracellular galactose oxidase reaction, and 3) a recently proposed oxido-reductive pathway which resembles the pathway for L-arabinose catabolism. It has been suggested in T. reesei and A. nidulans the oxido-reductive D-galactose pathway employs the enzymes from the L-arabinose pathway. It starts with the conversion of D-galactose to D-galactitol, probably carried by the xylose/arabinose reductase. The second step is catalyzed by L-arabitol dehydrogenase and the product of the reaction is an unusual sugar L-xylo-3-hexulose. We have identified the L-xylulose reductase possesses the activitywith this intermediate which is converted to D-sorbitol. Finally, D-sorbitol is oxidized to D-fructose, which enters glycolysis. We have studied the pathway in A. niger and uncovered a more complex picture. Apart from showing the possible involvement of the L-arabinose pathway enzymes, we identified two dehydrogenases specifically induced on D-galactose, suggesting that A. niger might have specific genes for catabolism of D-galactose rather than using metabolic crosstalk suggested for T. reesei and A. nidulans.

M3 - Conference abstract in proceedings

T3 - Fungal Genetics Reports

BT - 26th Fungal Genetics Conference

ER -

Mojzita D, Koivistoinen O, Vuoristo K, Ruohonen L, Penttilä M, Richard P. Oxido-reductive metabolism of L-arabinose and D-galactose in filamentous fungi: Metabolic crosstalk versus specific enzymes. In 26th Fungal Genetics Conference: Program and Abstracts. 2011. 328. (Fungal Genetics Reports; No. Supplement, Vol. 58).