Biodegradation Potential of SteccherinumOchraceum: Growth on Different Wood Types and Preliminary Evaluation of Enzymatic Activities

Abstract

White-rot fungi isa source of a great variety of oxidative and hydrolytic enzymes suitable for biotechnological applications, e.g. in pulp and paper, textile and food industries, bioethanol production, degradation of recalcitrant environmental pollutants,and others. Steccherinumochraceum is a xylotrophicwhite-rot basidiomycetethat can be found in variousclimatic zones on different woody substrates (mostly well decayed). For this research, seventeenstrains of S. ochraceumwere collected in different regions of Russia from various wood substrates (aspen, alder, oak, hazel, birch and willow). Phylogeneticanalyseswere performedbasedon the nucleotide sequences of ITS1, ITS2, 5.8S rRNA, 28S rRNA, β-tubulin and tef1.Oxidaseandcellulaseactivitieswereassessedbyplate-tests with ABTS and CMC. Forevaluation of biodegradation potential,solid state fermentation on alder and pine sawdust wasperformed. Weightanddensitylossaswellas the C:Nratioweremeasuredafter 90 days of cultivation.All S. ochraceum strains exhibited high oxidative activity towards ABTS, indicating secretion of oxidative enzymes (i.e. laccases and class II peroxidases). Cellulase activity was medium or low for most strains and in some strains – absent. Allstrainswereabletodegradealderandpinesawdust. There was no correlation between the enzymatic activity, biodegradation potential and geographic origin of S. ochraceum strains. However, S. ochraceum strains isolated from the same wood substrates exhibited similar characteristics in most cases. Strain LE-BIN 3398 was the most effective for degrading both alder and pine sawdust and could be regarded as a promising source of oxidative enzymes for biotechnology.


Keywords: basidiomycetes, biodegradation, solid state fermentation, oxidase activity, Steccherinumochraceum

References
[1] Lundell TK, Mäkelä MR, de Vries RP, Hildén KS. Genomics, lifestyles and future prospects of wood-decay and litter-decomposing basidiomycota. Advances in Botanical Research. 2014;70. 329-370

[2] Rodríguez-Couto S. Industrial and environmental applications of white-rot fungi.Mycosphere.2017;8(3):456–466.

[3] Wesenberg D, Kyriakides I, Spiros A. White-rot fungi and their enzymes for the. treatment of industrial dye effluents. Biotechnology Advances. 2003;22(1–2):161– 187.

[4] Gao D, DuL, Yang J, Wu W.-M, Liang H. A critical review of the application of white rot fungus to environmental pollution control. Critical Reviews in Biotechnology. 2010:30(1);70–77.

[5] Rouches E,Herpoël-Gimbert I, Steyer JP, Carrere H. (2016). Improvement of anaerobic degradation by white-rot fungi pretreatment of lignocellulosic biomass: A review. Renewable and Sustainable Energy Reviews. 2016;59:179–198.

[6] Eichlerová, I, Homolka L,Žifčáková L, Lisá L, Dobiášová P, Baldrian P. Enzymatic systems involved in decomposition reflects the ecology and taxonomy of saprotrophic fungi. Fungal Ecology. 2015;13:10–22.

[7] Uzan E, Nousiainen P, Balland V et al. High redox potential laccases from the ligninolytic fungi Pycnoporuscoccineus and Pycnoporussanguineus suitable for white biotechnology: From gene cloning to enzyme characterization and applications. Journal of Applied Microbiology. 2010;108(6):2199–213.

[8] MoiseenkoKV, Glazunova OA,Shakhova NV et al. Fungal adaptation to the advanced stages of wood decomposition: Insights from the Steccherinumochraceum. Microorganisms. 2019;7(11). 527-542 doi:10.3390/microorganisms7110527

[9] Glazunova OA, Trushkin NA, Moiseenko KV, Filimonov IS, Fedorova TV. Catalytic efficiency of basidiomycete laccases: Redox potential versus substrate-binding pocket structure. Catalysts. 2018;8(4): 152-160. doi:10.3390/catal8040152

[10] Glazunova OA, Polyakov, KM, Moiseenko KV, Kurzeev SA, Fedorova TV. Structurefunction study of two new middle-redox potential laccases from basidiomycetes Antrodiellafaginea and Steccherinummurashkinsky. International Journal of Biological Macromolecules. 2018;118:406–418. doi:10.1016/j.ijbiomac.2018.06.038

[11] Glazunova OA, Shakhova NV, Psurtseva NV et al. (2018). White-rot basidiomycetes Junghuhnia nitida and Steccherinumbourdotii: Oxidative potential and laccase properties in comparison with Trameteshirsuta and Coriolopsiscaperata.PLoS ONE. 2018;13(6):1–22. doi:10.1371/ journal.pone.0197667

[12] Chernykh AM, Myasoedova NM, Kolomytseva M et al. Laccase isoforms with unusual properties from the basidiomycete Steccherinumochraceum strain 1833. Journal of Applied Microbiology. 2008;105(6):2065–2075. doi:10.1111/j.1365- 2672.2008.03924.x