Growth of selected coprini on lignocellulosic substrates
E. Degradation of 14 C-labelled lignin: In conclusion from the former plate assays and lignocellulosic substrate growth test, we knew that all strains can produce types of
3.5 Conclusions and outlook
From the literature review presented in chapter 2, it becomes clear that more coprinoid mushroom species grow on woody material than thought so far. Following this notion, a set of experiments were performed to obtain a first impression on this group of fungi regarding their phenoloxidase activities and, as a consequence, their potential abilities to colonize wood. A collection of coprinoid strains was obtained from different sources. A control by molecular means (ITS sequences) revealed that several of these strains were misidentified on species (4 species in total), and in one instance also on genus level, and one strain was found not to belong to the form group of the coprini. The results confirm the difficulty in correct identification of coprinoid species by morphological characters (see also Naumann et al. 2007). Although for various strains a species name could not be assigned due to a lack of suitable reference sequences, experiments on enzymatic activities and growth on lignocellulosic material were still performed.
Several of the tested strains were found to grow on wood sawdust and in some instances, phenoloxidases, respective laccases were principally produced by the strains.
However, none of the coprini appeared to degrade the labelled lignin in the beech wood mixtures. Since CO2 released by the coprini was comparable to that of A. nidulans, we need to assume that the tested coprini rather grew e.g. on storage compounds in wood parenchyma.
In addition, growth was tested on leave litter since several coprini have been listed before as leave litter decomposing fungi (Soponsathien 1998, chapter 2 of this thesis).
Here, we discovered that most fungi grew on Q. robur, but not on A. platanoides leave litter. This different behaviour might be caused by different tannin types (Barbehenn et al. 2006), and/or by a different C:N ratios (Gartner and Cardon 2006) in the tested leave litters. Future work needs to clarify this.
Previously in chapter 2, it was repeatedly reported that several coprini species were growing on wood which was confirmed here for one Coprinus, one Coprinopsis, and for six Coprinellus species, respectively. In the same chapter, it had been questioned whether coprini are white-rot or brown-rot fungi. From the work presented in this chapter, neither can be supported. However, the work presented here is still preliminary and should be extended in the future to more species that have been perfectly defined
3. Growth of selected coprini on lignocellulosic substrates and detection of laccase activities
and where it is documented that they grow on wood. Such species can be collected from fruiting bodies from the nature and morphologically be defined. Having obtained more experience with coprini morphology during the performance of this thesis, the author of this document has become towards the end of this work quite experienced in the very difficult species determination by fruiting body morphology (see chapter 2 and 5 of this thesis, Naumann et al. 2007 and further unpublished work). With new strains isolated from fruiting bodies grown during the summer and autumn periods in 2005-2007, and possibly in the next vegetative growth periods, in the future targeted experiments on fungal growth, enzyme production and wood colonization and degradation should be performed. At the present stage, about 60 new isolates are available from own collection for such tests (not shown in this thesis).
3.6 Acknowledgments
We thank Prof. J. Trojanowsky for the idea of testing the labelled lignin and for providing it. Marina Horstmann is gratefully acknowledged for her technical support by the measurements of the 14CO2 lignin. The A. nidulans strain was kindly provided by Dr. Sven Krappmann.
3.7 References
Barbehenn RV, Jones CP, Karonen M, Salminen JP (2006) Tannin composition affects the oxidative activities of tree leaves. J. Chem. Ecol., 32, 2235-2251.
Basham JT (1958) Decay of trembling aspen. Can. J. Bot., 36, 491-505.
Basham JT, Morawski ZJR (1964) Cull studies, the defects and associated basidiomycete fungi in the heartwood of living trees in the forests of Ontario.
Department of Forestry Publication No. 1043. Queen’s Printer and Controller of Stationery, Ottawa, Canada.
Boulianne RP, Liu Y, Aebi M, Lu BC, Kües U (2000) Fruiting body development in Coprinus cinereus: regulated expression of two galectins secreted by a non-classical pathway. Microbiol., 146, 1841-1853.
Couto SR, Herrera JLT (2006) Industrial and biotechnological applications of laccases:
A review. Biotechnol. Adv., 24, 500-513.
Domański S (1983) Fungi that destroyed a Populus tremula stand in Lagów Lubuski.
Eur. J. For. Path., 13, 166-173.
Domański S (1984) Studies on the butt rots in common ash. Zeszyty Problemowe
3. Growth of selected coprini on lignocellulosic substrates and detection of laccase activities
Durán N, Esposito E (2000) Potential applications of oxidative enzymes and phenoloxidases-like compounds in wastewater and soil treatment: a review.
Appl. Cat B: Environ., 28, 83-99.
Gartner TB, Cardon ZG (2006) Site of leaf origin affects how mixed liiter decomposes.
Soil Biol. Biochem., 38, 2307-2317.
Gilbertson RL (1981) North American wood-rotting fungi that cause brown rots.
Mycotaxon, 12, 372-416.
Husain Q (2006) Potential applications of the oxidoreductive enzymes in the decolorization and detoxification of textile and other synthetic dyes from polluted water: A review. Cr. Rev. Biotechn., 26, 201-221.
Johannes C, Majcherczyk A (2000) Natural mediators in the oxidation of polycyclic aromatic hydrocarbons by laccase mediator systems. Appl. Environ. Microbiol., 66, 524-528.
Kües U (2000) Life history and developmental processes in the basidiomycete Coprinus cinereus. Microbiol. Mol. Biol. Rev., 64, 316-53.
Kumar S, Tamura K, Nei M (2004) MEGA3: Integrated software for molecular evolutionary genetics analysis and sequence alignment. Brief Bioinform., 5, 150-163.
Kühner R, Romagnesi H (1978) Flore Analytique des Champignons Supérieurs.
Masson, Paris, France.
Lindsey JP, Gilbertson RL (1978) Basidiomycetes that decay aspen in North America.
Bibl. Mycologica, 63, 1-406.
Matsumura E, Yamamoto E, Numata A, Kawano T, Shin T, Murao S (1986) Structures of the laccase-catalyzed oxidation products of hydroxybenzoic acids in the presence of ABTS (2,2´-azino-di-(3-ethylbenzothiazoline-6-sulfonic acid)).
Agric. Biol. Chem., 50, 1355-1357.
Naumann A, Navarro-González M, Sánchez-Hernández O, Hoegger PJ, Kües U (2007) Correct identification of wood-inhabiting fungi by ITS análisis. Curr. Trends Biotech. Pharm., In press.
Orton PD, Watling R (1979) British fungus flora. Agarics and Boleti 2. Coprinaceae Part 1: Coprinus. Her Majesty’s Stationary Office, Edinburg.
Pointing SB (2001) Feasibility of bioremediation by white-rot fungi. Appl. Microbiol.
Biotechnol., 57, 20-33.
3. Growth of selected coprini on lignocellulosic substrates and detection of laccase activities
Redhead SA, Vilgalys R, Moncalvo JM, Johnson J, Hopple JS Jr. (2001) Coprinus Pers.
and the disposition of Coprinus species sensu lato. Taxon, 50, 203-241.
Sagara N (1975) Ammonia fungi- A chemoecological grouping of terrestrial fungi.
Contrib. Biol. Lab. Kyoto Univ., 24, 205-276.
Sagara N (1992) Experimental disturbances and epigeous fungi. Chapter 23. In: Carroll GC, Wicklow DT (eds.) The fungal community, Marcel Dekker, Inc, New York, N.Y., USA.
Sambrook J, Russell DW (2001) Molecular Cloning. A Laboratory Manual. 3rd Edn.
Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.
Soponsathien S (1998) Some characteristics of ammonia fungi 1. In relation to their ligninolytic enzyme activities. J. Gen. Appl. Microbiol., 44, 337-345.
Trojanowsky J, Hüttermann A. (1987) Screening of wood inhabiting fungi for their capacity to degrade and to solubilize 14C-labelled lignin. Microbios, 50, 91-97.
Wesenberg D, Kyriakides I, Agathos SN (2003) White-rot fungi and their enzymes for the treatment of industrial dye effluents. Biotechnol. Adv., 22, 161-187.
White TJ, Bruns T, Lee S, Taylor JW (1990). Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In: Innis MA, Gelfand DH, Sninsky JJ, White TJ, (eds.), PCR Protocols: A Guide to Methods and Applications, Academic Press Inc., New York, pp. 315-322.
Zolan ME, Pukkila PJ (1986) Inheritance of DNA methylation in Coprinus cinereus.
Mol. Cell. Biol., 6, 195-200.