Influence of culture parameters on lignin metabolism by Phanerochaete chrysosporium
TL;DR: In this article, the effect of culture parameters on lignin decomposition was studied in shallow batch cultures of the ligninolytic wood-destroying HymenomycetePhanerochaete chrysosporium Burds.
Abstract: Culture parameters influencing metabolism of synthetic14C-lignins to14CO2 in defined media have been studied in shallow batch cultures of the ligninolytic wood-destroying HymenomycetePhanerochaete chrysosporium Burds. Study of the effect of O2 concentration in the gas phase above non-agitated cultures indicated essentially complete absence of attack on the lignin polymer at 5% O2 in N2, and a 2- to 3-fold enhancement by 100% O2 as compared to air (21% O2). Agitation of the cultures resulting in the formation of mycelial pellets greatly suppressed lignin decomposition. The optimum culture pH for lignin decomposition was 4 to 4.5, with marked suppression above 5.5 and below 3.5. The source of nutrient nitrogen (NO
3
−
, NH
4
+
, amino acids) had little influence on lignin decomposition, but the concentration of nitrogen was critical; decomposition at 24 mM was only 25–35% of that at 2.4 mM N. Thiamine was the only vitamin required for growth and lignin decomposition. Under the optimum conditions developed, decomposition of 5 mg of synthetic lignin was accompanied by utilization of approximately 100 mg of glucose. The influence of the various culture parameters was analogous for metabolism of synthetic lignin labeled in the ring-,side chain-, and methoxyl carbon atoms.
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TL;DR: In this article, the authors reviewed the rates at which coarse wood debris is added and removed from ecosystems, the biomass found in streams and forests, and many functions that CWD serves.
Abstract: Publisher Summary This chapter reviews the rates at which Coarse Woody Debris (CWD) is added and removed from ecosystems, the biomass found in streams and forests, and many functions that CWD serves. CWD is an important component of temperate stream and forest ecosystems and is added to the ecosystem by numerous mechanisms, including wind, fire, insect attack, pathogens, competition, and geomorphic processes. Many factors control the rate at which CWD decomposes, including temperature, moisture, the internal gas composition of CWD, substrate quality, the size of the CWD, and the types of organisms involved. The mass of CWD in an ecosystem ideally represents the balance between addition and loss. In reality, slow decomposition rates and erratic variations in input of CWD cause the CWD mass to deviate markedly from steady-state projections. Many differences correspond to forest type, with deciduous-dominated systems having generally lower biomass than conifer-dominated systems. Stream size also influences CWD mass in lotic ecosystems, while successional stage dramatically influences CWD mass in boat aquatic and terrestrial settings. This chapter reviews many of these functions and concludes that CWD is an important functional component of stream and forest ecosystems. Better scientific understanding of these functions and the natural factors influencing CWD dynamics should lead to more enlightened management practices.
3,247 citations
TL;DR: N added to decomposing organic matter often has no effect or a negative effect on microbial activity, at least in the long term, and this statement is supported by more than 60 papers cited.
Abstract: Summary
(1) N added to decomposing organic matter often has no effect or a negative effect on microbial activity, at least in the long term. More than 60 papers are cited in support of this statement.
(2) The negative effect of N is mainly found with recalcitrant organic matter with a high C/N ratio (straw, wood, etc.), whereas a positive effect of N is common for easily degradable organic material with low C/N ratio.
(3) The negative effect of N could be explained by: (i) N disturbs the outcome of competition between potent and less potent decomposers; (ii) through ‘ammonia metabolite repression’, N blocks production of certain enzymes, at least in basidiomycetes, and enhances breakdown of the most available cellulose, whereby recalcitrant lignocellulose accumulates; (iii) amino compounds condense with polyphenols and other decomposition products, forming ‘browning precursors’ which are toxic or inhibitory.
(4) The effect of adding N may depend on the microflora present.
(5) There are indications that some microorganisms have a ‘luxury uptake’ of N when it is present in sufficient amounts, thereby delaying N mineralization.
(6) The addition of N seems to increase the formation of water-soluble, brown, recalcitrant compounds, but to decrease the amount of humus formed.
1,159 citations
TL;DR: Model studies suggest that the ability of Phanerochaete chrysosporium to metabolize these compounds is dependent on the extracellular lignin-degrading enzyme system of this fungus.
Abstract: The white rot fungus Phanerochaete chrysosporium degraded DDT [1,1,-bis(4-chlorophenyl)-2,2,2-trichloroethane], 3,4,3',4'-tetrachlorobiphenyl, 2,4,5,2',-4',5'-hexachlorobiphenyl, 2,3,7,8-tetrachlorodibenzo-p-dioxin, lindane (1,2,3,4,5,6-hexachlorocylohexane), and benzo[a]pyrene to carbon dioxide. Model studies, based on the use of DDT, suggest that the ability of Phanerochaete chrysosporium to metabolize these compounds is dependent on the extracellular lignin-degrading enzyme system of this fungus.
910 citations
TL;DR: The white rot fungus Pycnoporus cinnabarinus was characterized with respect to its set of extracellular phenoloxidases and a single predominant laccase and a lack of lignin- or manganese-type peroxidase make this organism an interesting model for further studies of possible alternative pathways of ligningin degradation by white rot fungi.
Abstract: The white rot fungus Pycnoporus cinnabarinus was characterized with respect to its set of extracellular phenoloxidases. Laccase was produced as the predominant extracellular phenoloxidase in conjunction with low amounts of an unusual peroxidase. Neither lignin peroxidase nor manganese peroxidase was detected. Laccase was produced constitutively during primary metabolism. Addition of the most effective inducer, 2,5-xylidine, enhanced laccase production ninefold without altering the isoenzyme pattern of the enzyme. Laccase purified to apparent homogeneity was a single polypeptide having a molecular mass of approximately 81,000 Da, as determined by calibrated gel filtration chromatography, and a carbohydrate content of 9%. The enzyme displayed an unusual behavior on isoelectric focusing gels; the activity was split into one major band (pI, 3.7) and several minor bands of decreasing intensity which appeared at regular, closely spaced intervals toward the alkaline end of the gel. Repeated electrophoresis of the major band under identical conditions produced the same pattern, suggesting that the laccase was secreted as a single acidic isoform with a pI of about 3.7 and that the multiband pattern was an artifact produced by electrophoresis. This appeared to be confirmed by N-terminal amino acid sequencing of the purified enzyme, which yielded a single sequence for the first 21 residues. Spectroscopic analysis indicated a typical laccase active site in the P. cinnabarinus enzyme since all three typical Cu(II)-type centers were identified. Substrate specificity and inhibitor studies also indicated the enzyme to be a typical fungal laccase. The N-terminal amino acid sequence of the P. cinnabarinus laccase showed close homology to the N-terminal sequences determined for laccases from Trametes versicolor, Coriolus hirsutus, and an unidentified basidiomycete, PM1. The principal features of the P. cinnabarinus enzyme system, a single predominant laccase and a lack of lignin- or manganese-type peroxidase, make this organism an interesting model for further studies of possible alternative pathways of lignin degradation by white rot fungi.
749 citations
TL;DR: A Mn(II)-dependent peroxidase found in the extracellular medium of ligninolytic cultures of the white rot fungus, Phanerochaete chrysosporium, was purified and the absorption spectrum of the enzyme indicates the presence of a heme prosthetic group.
716 citations
References
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TL;DR: In this paper, the reliability of the various Somogyi-Shaffer-Hartmann (SHH) copper reagents for glucose determination in biological material has been established, which can be accomplished by omission of the iodide and iodate in their preparation, since these interfere with the molybdate color reagents.
10,346 citations
"Influence of culture parameters on ..." refers methods in this paper
...Residual medium glucose was determined by the procedure of Nelson (1944)....
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Journal Article•
TL;DR: In this article, various steps, including hydrolysis, neutralization, evaporation, separation, elution, and final sugar determination have all been studied to minimize time requirements and to determine the errors contributed by each step.
Abstract: Quantitative chromatographic techniques are generally sensitive, but suffer from being expensive in man-power requirements. In this paper, methods are described for reducing the cost of such work. The various steps, including hydrolysis, neutralization, evaporation, separation, elution, and final sugar determination have all been studied to minimize time requirements and to determine the errors contributed by each step. The usefulness and present limitations of the techniques are described. A comparison has been made between the pentosan content of pulps determined by the Technical Association of the Pulp and Paper Industry's method and the values obtained by chromatographic analysis. At high pentosan content, agreement is satisfactory. At low pentosan content, the TAPPI method is shown to have high inherent errors due to the fact that the residual unhydrolyzed cellulose contains relatively large amounts of pentosan. The error due to this cause can be eliminated by total hydrolysis of the pulp, followed by an appropriate pentosan analysis.
321 citations
"Influence of culture parameters on ..." refers methods in this paper
...Powdered cellulose (Solka Flok SW-40, Brown Co., Berlin, N.H.) was from wood pulp; this cellulose was analyzed (Saeman et al., 1954) and found to contain approximately 90 ~ glucan, 8 % xylan, and 2 mannan....
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TL;DR: Decomposition of C-labeled lignin to CO(2) by the lignIn-decomposing fungi Phanerochaete chrysosporium and Coriolus versicolor required a growth substrate such as cellulose or glucose.
Abstract: Decomposition of 14C-labeled lignin to 14CO2 by the lignin-decomposing fungi Phanerochaete chrysosporium and Coriolus versicolor required a growth substrate such as cellulose or glucose. Growth with lignin as sole carbon addition to an otherwise complete medium was negligible.
279 citations
TL;DR: A definitive assay for microbiological and biochemical research on the biodegradation of lignin was developed using radioactive synthetic lignins specifically labeled in the side chains, aromatic rings or in the methoxyl groups.
Abstract: A definitive assay for microbiological and biochemical research on the biodegradation of lignin was developed using radioactive synthetic lignins specifically labeled in the side chains, aromatic rings or in the methoxyl groups. The [14C]lignins were prepared by oxidative polymerization with peroxidase and H2O2 Of specifically labeled coniferyl alcohol (4-hydroxy-3-methyoxycinnamyl alcohol). The synthetic polymers were shown by spectroscopic and chemical methods to contain the same intermonomer linkages found in natural lignins. Incubation of the [14C]lignins with known lignin-degrading fungi and with a forest soil resulted in 14CO2 evolution.
205 citations
"Influence of culture parameters on ..." refers methods in this paper
...A sensitive and definitive biodegradation assay based on the decomposition of synthetic 14C-lignins to 14CO2 has been reported (Kirk et al., 1975) for lignins synthesized with 14C in the ring, side chain, or methoxyl portions of the polymer....
[...]
...Synthetic [U-ring-14C] -, [methoxyl-14C]-, and [side chain (fi,y)-14C]lignins with specific activities of 9.3 x 104, 9.1 x 104, and 2.2 x 105 dpm/mg were prepared as described earlier (Kirk et al., 1975)....
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...Aliquots (1 mI) from the complete media were taken for radioactivity determinations; a modified Bray's scintillation fluid was used (Kirk et al., 1975)....
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...This was found to remove all evolved I~COz, which was trapped by placing the exit needle in 10ml of an ethanolamine-containing scintillation fluid (Kirk et al., 1975) in a 20-ml scintillation vial....
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TL;DR: In this article, the authors compared three sound and three sound lignins from spruce on the basis of functional group analyses, spectroscopic characterizations and chemical degradation studies.
Abstract: Heavily degraded spruce lignins isolated from wood decayed by Coriolus versicolor and from wood decayed by Polyporus anceps were compared with three sound lignins from spruce on the basis of functional group analyses, spectroscopic characterizations and chemical degradation studies. Results did not reveal any differences in the degradation of lignin by the two fungi. The fungus-degraded lignins had much lower phenolic hydroxyl contents than sound lignins, were lower in aliphatic hydroxyl content, and had about 0.2 alpha-carbonyl group (alpha-to aromatic rings) and 0.5 carboxyl group per C9-unit ("monomer" unit). The carboxyl groups were conjugated, approximately one-third being aromatic-conjugated, and the remainder being alpha,beta-unsaturated. The degraded lignins were about 25per thousand deficient in methoxyl content, but this loss of methoxyl groups was not accompanied by formation of persisting new phenolic hydroxyl groups. Phenolic hydroxyl groups resulting from aromatic hydroxylation also were absent. On oxidative degradation of the methylated lignins, the yields of methoxylated benzoic acids from the fungus-degraded lignins were substantially different than the yields from sound lignins. Similarly, acid hydrolysis gave markedly different yields of principal single-ring products from the degraded lignins. Most of the differences between sound and degraded lignins in the UV, IR and PMR spectroscopic characteristics reflect the higher contents of alpha-carbonyl groups and the conjugated carboxyl groups in the degraded material. A substantially decreased number of aromatic rings in the degraded lignins is indicated by the IR spectra. The data indicate that the polymeric degraded lignins contain both oxidized side chains and the aliphatic residues left after oxidative cleavage of aromatic rings.
189 citations