Transcription of lignocellulose-decomposition associated genes, enzyme activities and production of ethanol upon bioconversion of waste substrate by Phlebia radiata

Mari Annukka Mäkinen, Netta Risulainen, Hans Kristian Mattila, Taina Kristina Lundell

Research output: Contribution to journalArticleScientificpeer-review


Previously identified twelve plant cell wall degradation-associated genes of the white rot fungus Phlebia radiata were studied by RT-qPCR in semi-aerobic solid-state cultures on lignocellulose waste material, and on glucose-containing reference medium. Wood-decay-involved enzyme activities and ethanol production were followed to elucidate both the degradative and fermentative processes. On the waste lignocellulose substrate, P. radiata carbohydrate-active enzyme (CAZy) genes encoding cellulolytic and hemicellulolytic activities were significantly upregulated whereas genes involved in lignin modification displayed a more complex response. Two lignin peroxidase genes were differentially expressed on waste lignocellulose compared to glucose medium, whereas three manganese peroxidase-encoding genes were less affected. On the contrary, highly significant difference was noticed for three cellulolytic genes (cbhI_1, eg1, bgl1) with higher expression levels on the lignocellulose substrate than on glucose. This indicates expression of the wood-attacking degradative enzyme system by the fungus also on the recycled, waste core board material. During the second week of cultivation, ethanol production increased on the core board to 0.24 g/L, and extracellular activities against cellulose, xylan, and lignin were detected. Sugar release from the solid lignocellulose resulted with concomitant accumulation of ethanol as fermentation product. Our findings confirm that the fungus activates its white rot decay system also on industrially processed lignocellulose adopted as growth substrate, and under semi-aerobic cultivation conditions. Thus, P. radiata is a good candidate for lignocellulose-based renewable biotechnology to make biofuels and biocompounds from materials with less value for recycling or manufacturing.
Original languageEnglish
JournalApplied Microbiology and Biotechnology
Issue number13
Pages (from-to)5657-5672
Number of pages16
Publication statusPublished - Jul 2018
MoE publication typeA1 Journal article-refereed

Fields of Science

  • 414 Agricultural biotechnology
  • Fungal biology
  • Genomics
  • Fungal metabolites
  • Wood decay fungi
  • Lignocellulose biodegradation
  • 1183 Plant biology, microbiology, virology
  • Fungal biotechnology
  • Mycology
  • 219 Environmental biotechnology
  • Waste bioconversion

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