RNAseq reveals hydrophobins that are involved in the adaptation of aspergillus nidulans to lignocellulose

Brown, N. A., Ries, L. N. A., Reis, T. F., Rajendran, R., Corrêa Dos Santos, R. A., Ramage, G. , Riaño-Pachón, D. M. and Goldman, G. H. (2016) RNAseq reveals hydrophobins that are involved in the adaptation of aspergillus nidulans to lignocellulose. Biotechnology for Biofuels, 9, 145. (doi: 10.1186/s13068-016-0558-2) (PMID:27437031) (PMCID:PMC4950808)

Abstract

Background Sugarcane is one of the world’s most profitable crops. Waste steam-exploded sugarcane bagasse (SEB) is a cheap, abundant, and renewable lignocellulosic feedstock for the next-generation biofuels. In nature, fungi seldom exist as planktonic cells, similar to those found in the nutrient-rich environment created within an industrial fermenter. Instead, fungi predominantly form biofilms that allow them to thrive in hostile environments. Results In turn, we adopted an RNA-sequencing approach to interrogate how the model fungus, Aspergillus nidulans, adapts to SEB, revealing the induction of carbon starvation responses and the lignocellulolytic machinery, in addition to morphological adaptations. Genetic analyses showed the importance of hydrophobins for growth on SEB. The major hydrophobin, RodA, was retained within the fungal biofilm on SEB fibres. The StuA transcription factor that regulates fungal morphology was up-regulated during growth on SEB and controlled hydrophobin gene induction. The absence of the RodA or DewC hydrophobins reduced biofilm formation. The loss of a RodA or a functional StuA reduced the retention of the hydrolytic enzymes within the vicinity of the fungus. Hence, hydrophobins promote biofilm formation on SEB, and may enhance lignocellulose utilisation via promoting a compact substrate-enzyme-fungus structure. Conclusion This novel study highlights the importance of hydrophobins to the formation of biofilms and the efficient deconstruction of lignocellulose.

• Item Type: Articles
• Additional Information: We would like to thank the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) in Brazil for funding this research. Rothamsted Research receives grant-aided support from the Biotechnology and Biological Sci‑ ences Research Council (BBSRC) UK as part of the 20:20® wheat programme. Neil Brown receives support from the BBSRC National Capability PHI-base programme [BB/J/004383/1] and the BBSRC Future Leader Fellowship [BB/ N011686/1].
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Rajendran, Dr Ranjith and Ramage, Professor Gordon
• Authors: Brown, N. A., Ries, L. N. A., Reis, T. F., Rajendran, R., Corrêa Dos Santos, R. A., Ramage, G., Riaño-Pachón, D. M., and Goldman, G. H.
• College/School: College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing > Dental School
• Journal Name: Biotechnology for Biofuels
• Publisher: BioMed Central Ltd.
• ISSN: 1754-6834
• ISSN (Online): 1754-6834
• Published Online: 19 July 2016
• Copyright Holders: Copyright © 2016 The Authors
• First Published: First published in Biotechnology for Biofuels 9:145
• Publisher Policy: Reproduced under a Creative Commons License