Lignocellulose-converting enzyme activity profiles correlate with molecular systematics and phylogeny grouping in the incoherent genus Phlebia (Polyporales, Basidiomycota).
BACKGROUND
The fungal genus Phlebia consists of a number of species that are significant in wood decay. Biotechnological potential of a few species for enzyme production and degradation of lignin and pollutants has been previously studied, when most of the species of this genus are unknown. Therefore, we carried out a wider study on biochemistry and systematics of Phlebia species.


METHODS
Isolates belonging to the genus Phlebia were subjected to four-gene sequence analysis in order to clarify their phylogenetic placement at species level and evolutionary relationships of the genus among phlebioid Polyporales. rRNA-encoding (5.8S, partial LSU) and two protein-encoding gene (gapdh, rpb2) sequences were adopted for the evolutionary analysis, and ITS sequences (ITS1+5.8S+ITS2) were aligned for in-depth species-level phylogeny. The 49 fungal isolates were cultivated on semi-solid milled spruce wood medium for 21 days in order to follow their production of extracellular lignocellulose-converting oxidoreductases and carbohydrate active enzymes.


RESULTS
Four-gene phylogenetic analysis confirmed the polyphyletic nature of the genus Phlebia. Ten species-level subgroups were formed, and their lignocellulose-converting enzyme activity profiles coincided with the phylogenetic grouping. The highest enzyme activities for lignin modification (manganese peroxidase activity) were obtained for Phlebia radiata group, which supports our previous studies on the enzymology and gene expression of this species on lignocellulosic substrates.


CONCLUSIONS
Our study implies that there is a species-level connection of molecular systematics (genotype) to the efficiency in production of both lignocellulose-converting carbohydrate active enzymes and oxidoreductases (enzyme phenotype) on spruce wood. Thus, we may propose a similar phylogrouping approach for prediction of lignocellulose-converting enzyme phenotypes in new fungal species or genetically and biochemically less-studied isolates of the wood-decay Polyporales.
Department of Food and Environmental Sciences, Division of Microbiology and Biotechnology, University of Helsinki, Viikki Biocenter 1, P.O.B. 56, FIN-00014, Helsinki, Finland. jaana.kuuskeri@helsinki.fi.
Jaana
J
Kuuskeri
Department of Food and Environmental Sciences, Division of Microbiology and Biotechnology, University of Helsinki, Viikki Biocenter 1, P.O.B. 56, FIN-00014, Helsinki, Finland. miia.r.makela@helsinki.fi.
Miia R
MR
Mäkelä
Department of Forest Sciences, University of Helsinki, Helsinki, Finland. jarkko.isotalo@helsinki.fi.
Jarkko
J
Isotalo
Department of Food and Environmental Sciences, Division of Microbiology and Biotechnology, University of Helsinki, Viikki Biocenter 1, P.O.B. 56, FIN-00014, Helsinki, Finland. ilona.oksanen1@hotmail.com.
Ilona
I
Oksanen
Department of Food and Environmental Sciences, Division of Microbiology and Biotechnology, University of Helsinki, Viikki Biocenter 1, P.O.B. 56, FIN-00014, Helsinki, Finland. taina.lundell@helsinki.fi.
Taina
T
Lundell
D001487:Basidiomycota / Q000145:classification* / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D001711:Biotransformation; D016000:Cluster Analysis; D003470:Culture Media / Q000737:chemistry; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D024581:Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating) / Q000235:genetics; D008031:Lignin / Q000378:metabolism*; D008828:Microbiological Techniques; D008969:Molecular Sequence Data; D010802:Phylogeny; D012319:RNA Polymerase II / Q000235:genetics; D012335:RNA, Ribosomal / Q000235:genetics; D012340:RNA, Ribosomal, 5.8S / Q000235:genetics; D017422:Sequence Analysis, DNA
D003470:Culture Media; D004271:DNA, Fungal; D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer; D012335:RNA, Ribosomal; D012340:RNA, Ribosomal, 5.8S; C065096:RNA, ribosomal, 26S; C036909:lignocellulose; D008031:Lignin; D024581:Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating); D012319:RNA Polymerase II