Abstract
Filamentous fungi degrade complex plant material to its monomeric building blocks, which have many biotechnological applications. Transcription factors play a key role in plant biomass degradation, but little is known about their interactions in the regulation of polysaccharide degradation. Here, we deepened the knowledge about the storage polysaccharide regulators AmyR and InuR in Aspergillus niger. AmyR controls starch degradation, while InuR is involved in sucrose and inulin utilization. In our study, the phenotypes of A. niger parental, ΔamyR, ΔinuR and ΔamyRΔinuR strains were assessed in both solid and liquid media containing sucrose or inulin as carbon source to evaluate the roles of AmyR and InuR and the effect of culture conditions on their functions. In correlation with previous studies, our data showed that AmyR has a minor contribution to sucrose and inulin utilization when InuR is active. In contrast, growth profiles and transcriptomic data showed that the deletion of amyR in the ΔinuR background strain resulted in more pronounced growth reduction on both substrates, mainly evidenced by data originating from solid cultures. Overall, our results show that submerged cultures do not always reflect the role of transcription factors in the natural growth condition, which is better represented on solid substrates. Importance: The type of growth has critical implications in enzyme production by filamentous fungi, a process that is controlled by transcription factors. Submerged cultures are the preferred setups in laboratory and industry and are often used for studying the physiology of fungi. In this study, we showed that the genetic response of A. niger to starch and inulin was highly affected by the culture condition, since the transcriptomic response obtained in a liquid environment did not fully match the behavior of the fungus in a solid environment. These results have direct implications in enzyme production and would help industry choose the best approaches to produce specific CAZymes for industrial purposes.
Original language | English |
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Article number | 438 |
Pages (from-to) | 1-14 |
Number of pages | 14 |
Journal | Journal of fungi (Basel, Switzerland) |
Volume | 9 |
Issue number | 4 |
DOIs | |
Publication status | Published - 4 Apr 2023 |
Bibliographical note
Publisher Copyright:© 2023 by the authors.
Funding
R.S.K. and S.G. were supported by a grant of the Applied Science Division (TTW) of NWO and the Biotechnology and Safety Program of the Ministry of Infrastructure and Water Management. S.S.-C. was supported by a Postdoctoral Researcher fellowship from Mexico Government (CONACYT, support 360912). The work (proposal: 10.46936/fics.proj.2018.50379/60006403) conducted by the U.S. Department of Energy Joint Genome Institute (https://ror.org/04xm1d337), a DOE Office of Science User Facility, is supported by the Office of Science of the U.S. Department of Energy operated under Contract No. DE-AC02-05CH11231.
Funders | Funder number |
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U.S. Department of Energy Joint Genome Institute | |
U.S. Department of Energy | DE-AC02-05CH11231 |
Office of Science | |
Consejo Nacional de Ciencia y Tecnología | 360912 |
Nederlandse Organisatie voor Wetenschappelijk Onderzoek | |
Ministry of Infrastructure and Water Management |
Keywords
- Aspergillus niger
- transcription factors
- AmyR
- InuR
- liquid cultivation
- solid cultivation