The roles of the alternative NADH dehydrogenases during oxidative stress in cultures of the filamentous fungus Aspergillus niger

Andrew O'Donnell, Linda M. Harvey, Brian Mcneil

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Despite the importance of filamentous fungi in the biotechnology industry, little is known about their metabolism under the stressful conditions experienced in typical production fermenters. In the present study, oxygen enrichment was used to recreate an industrial batch process, and the effects of the increasing dissolved oxygen tension were studied as regards the cellular metabolism. It was found that elevated dissolved oxygen tension led to an oxidatively stressful environment, as detailed by rapid initial increases in reactive oxygen species (ROS) concentrations and antioxidant enzyme activities. Intracellular protein concentrations also decreased in oxygenated cultures; this appeared to be concomitant with a decrease in the adenosine-5'-triphosphate (ATP) pool in these cultures. Oxygenated cultures showed early senescence and death compared to aerated control cultures. Despite earlier studies proposing various mechanisms for such findings in fungal cultures subjected to oxidative stress, these findings can best be explained by the fact that in such cultures the activity of alternative NADH dehydrogenases was significantly increased, which served to maintain lower ROS concentrations throughout the duration of the process but in doing so also reduced the ability of the organism to create a proton motive force by which to drive ATP synthesis. The findings of the present study help further our understanding of the central roles of these highly conserved enzymes within fungal metabolism under oxidative stress.
Original languageEnglish
Pages (from-to)359-369
Number of pages11
JournalFungal biology
Volume115
Issue number4-5
DOIs
Publication statusPublished - May 2011

Fingerprint

NADH Dehydrogenase
NADH dehydrogenase
Aspergillus niger
Oxidative Stress
Fungi
oxidative stress
adenosine triphosphate
fungus
Oxygen
dissolved oxygen
fungi
metabolism
reactive oxygen species
Reactive Oxygen Species
Adenosine Triphosphate
Proton-Motive Force
fermenters
Enzymes
Biotechnology
biotechnology

Keywords

  • adenosine triphosphate
  • aspergillus niger
  • biomass
  • cell culture techniques
  • fungal proteins
  • nadh dehydrogenase
  • oxidative stress
  • oxygen
  • reactive oxygen species

Cite this

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title = "The roles of the alternative NADH dehydrogenases during oxidative stress in cultures of the filamentous fungus Aspergillus niger",
abstract = "Despite the importance of filamentous fungi in the biotechnology industry, little is known about their metabolism under the stressful conditions experienced in typical production fermenters. In the present study, oxygen enrichment was used to recreate an industrial batch process, and the effects of the increasing dissolved oxygen tension were studied as regards the cellular metabolism. It was found that elevated dissolved oxygen tension led to an oxidatively stressful environment, as detailed by rapid initial increases in reactive oxygen species (ROS) concentrations and antioxidant enzyme activities. Intracellular protein concentrations also decreased in oxygenated cultures; this appeared to be concomitant with a decrease in the adenosine-5'-triphosphate (ATP) pool in these cultures. Oxygenated cultures showed early senescence and death compared to aerated control cultures. Despite earlier studies proposing various mechanisms for such findings in fungal cultures subjected to oxidative stress, these findings can best be explained by the fact that in such cultures the activity of alternative NADH dehydrogenases was significantly increased, which served to maintain lower ROS concentrations throughout the duration of the process but in doing so also reduced the ability of the organism to create a proton motive force by which to drive ATP synthesis. The findings of the present study help further our understanding of the central roles of these highly conserved enzymes within fungal metabolism under oxidative stress.",
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The roles of the alternative NADH dehydrogenases during oxidative stress in cultures of the filamentous fungus Aspergillus niger. / O'Donnell, Andrew; Harvey, Linda M.; Mcneil, Brian.

In: Fungal biology, Vol. 115, No. 4-5, 05.2011, p. 359-369.

Research output: Contribution to journalArticle

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