Summary
We have utilized strains of three actinomycete species, Actinomadura sp, Streptomyces cyaneus and Thermomonospora mesophila, to study the solubilisation of lignocellulose. The production of extracellular proteins, was measured for each of the organisms during 17 days growth using medium containing either glucose or ball-milled straw. Some of the extracellular proteins (as identified by SDS gel electrophoresis) were present under both growth conditions, but others were specific to the type of medium or the period of incubation. The levels of proteins were compared with the abilities of the extracellular protein preparations to solubilise a substrate of 14C-labelled lignocellulose. About 6% of the radioactive material were solubilised when the extracellular proteins from the cultures grown on glucose were incubated with the substrate, compared to 20–30% that were solubilised by the extracellular proteins from the cultures grown on ball-milled straw. Partial characterisation of an enzyme from S. cyaneus responsible for the solubilisation of lignocellulose was achieved by gel filtration of the extracellular proteins, using Superose 12. Material that eluted from the column with an apparent molecular weight of about 20 000 accounted for all of the solubilisation of 14C-labelled (i.e. lignin-derived) moieties. In contrast, when the eluate was tested for the presence of cellulases and xylanases most of the activities were found in fractions containing material with an apparent molecular weight of about 45 000. We conclude that in cultures of S. cyaneus grown on ball-milled straw, a single extracellular enzyme is responsible for the solubilisation of lignin in lignocellulose, and that this enzyme is unlikely to be a cellulase or a xylanase.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Antai SP, Crawford DL (1981) Degradation of Softwood, Hardwood, and Grass Lignocelluloses by two Streptomyces Strains. Appl Environ Microbiol 42:378–380
Borgmeyer JR, Crawford DL (1985) Production and characterization of polymeric lignin degradation intermediates from two different Streptomyces spp. Appl Environ Microbiol 49:273–278
Bradford MM (1976) A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem 72:248–254
Crawford DL, Barder MJ, Pometto III AL, Crawford RL (1982) Chemistry of softwood lignin degradation by Streptommyces viridosporus. Arch Microbiol 131:140–145
Cross T, Attwell RW (1974) Recovery of viable thermoactinomycete endospores from deep mud cores. In: Berker AN, Gould GW, Wolf J (eds) Spore research 1973. Academic Press, London, pp 11–20
Fenn P, Kirk TK (1981) Relationship of nitrogen to the onset and suppression of ligninolytic activity and secondary metabolism in Phanerochaete chrysosporium. Arch Microbiol 130:59–65
Grüninger H, Fiechter A (1986) A novel highly thermostable d-xylanase. Enzyme Microb Technol 8:309–314
Kawai S, Umezawa T, Higuchi T (1985) Metabolism of a Nonphenolic β-o-4 Lignin Substructure Model Compound by Coriolus versicolor. Agric Biol Chem 49(8):2325–2330
Kirk TK, Nakatsubo F, Reid ID (1983) Further study discounts role for singlet oxygen in fungal degradation of lignin model compounds. Biochem Biophys Res Comm 3:200–204
Laemmli UK (1970) Cleavage of structural proteins during the assembly of the head bacteriophage T4. Nature 227:680–685
McCarthy AJ, Broda P (1984) Screening for lignin-degrading actinomycetes and characterization of their activity against [14C]—lignin-labelled wheat lignocellulose. J Gen Microbiol 130:2905–2913
McCarthy AJ, McDonald MJ, Paterson A, Broda P (1984) Degradation of [14C] lignin-labelled wheat lignocellulose by white-rot fungi. J Gen Microbiol 130:1023–1030
McCarthy AJ, Paterson A, Broda P (1986) Lignin solubilisation by Thermomonospora mesophila. Appl Microbiol Biotechnol 24:347–352
Mopper K, Gindler EM (1973) A new noncorrosive dye reagent for automatic sugar chromatography. Anal Biochem 56:440–442
Nakatsubo F, Kirk TK, Shimada M, Higuchi T (1981) Metabolism of a phenylcoumaran substructure lignin model compound in ligninolytic cultures of Phanerochaete chrysosporium. Arch Microbiol 128:416–420
Phelan MB, Crawford DL, Pometto III AL (1979) Isolation of lignocellulose-decomposing actinomycetes and degradation of specifically 14C-labelled lignocelluloses by six selected Streptomyces strains. Can J Microbiol 25:1270–1276
Pometto III AL, Crawford DL (1986) Catabolic fate of Streptomyces viridosporus T7A — produced, acid precipitable polymeric lignin upon incubation with ligninolytic Streptomyces species and Phanerochaete chrysosporium. Appl Envir Microbiol 51(i):171–179
Righetti PG, Gianazza E (1980) pH mobility curves of proteins by isoelectric focusing combined with electrophoresis at right angles. In: Radola BJ (ed) Electrophoresis 79. Walter de Gryter, Berlin, New York, pp 23–38
Rinderknecht H, Wilding P, Haverback BJ (1967) A new method for the determination of d-Amylase, Experimentia 23:1805
Sinner M, Puls J (1978) Non-corrosive dye reagent for detection of reducing sugars in borate complex ion-exchange chromatography. J Chromatog 156:197–204
Tansey MR (1971) Agar diffusion assay for cellulolytic ability of thermophilic fungi. Archiv Mikrobiol 77:1–11
Tien M, Kirk TK (1983) Lignin degrading enzyme from the hymenomycete Phanerochaete chrysosporium. Science 221:661–663
Tien M Tu C-PD (1987) Cloning and sequencing of a cDNA for a ligninase from Phanerochaete chrysosporium. Nature 326:520–523
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Clark Mason, J., Richards, M., Zimmermann, W. et al. Identification of extracellular proteins from actinomycetes responsible for the solubilisation of lignocellulose. Appl Microbiol Biotechnol 28, 276–280 (1988). https://doi.org/10.1007/BF00250455
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00250455