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PubMed1977

Microbial activity in soil enriched with preparations of AS-lignin and lignofulvonic acid.

In chernozem soil, enriched with preparations of AS-lignin or lignofulvonic acid, an increased production of carbon dioxide was observed during a 4-week incubation, and, as compared with the non-amended control, an increased number of bacteria but not of actinomycetes was detected. Increased numbers of fungi were detected only in the variant with AS-lignin at the end of the incubation. The relative incidence of bacteria utilizing vanillin, syringic acid or protocatechuic acid as the only carbon sources increased in the enriched medium. Oxidation of vanillic acid, syringic acid and to a lesser extent of coumarin increased in suspensions of soils incubated with AS-lignin or fulvic acid. The results obtained indicate that bacteria are involved in the mineralization of the added substrates and confirm the relationship between metabolism of these compounds and simple aromatic derivatives.

Actinomycetaceae↗

PubMed1993

Role of organic acid chelators in manganese regulation of lignin degradation by Phanerochaete chrysosporium.

Nitrogen, carbon, and manganese are potent regulators of lignin degradation, but although nitrogen and carbon elicit a generalizated response when cells are starved, manganese is a relatively specific regulator of lignin and manganese peroxidase (LiP and MnP, respectively). At high manganese levels, MnP is induced, and LiP is repressed. At low Mn levels, MnP is repressed, and LiP is induced. Organic acid chelators are very important in attaining LiP repression with high Mn. Both mineralization and lignin depolymerization are regulated by manganese in the presence of organic acid chelators. As long as the chelators keep Mn(II) and Mn(III) in solution, repression is observed, but eventually, dismutation reactions cause the formation and precipitation of Mn (IV) as MnO2. Repression is immediately relieved, and depolymerization and mineralization proceed at a high rate.

Acids↗

PubMed2003

Genetic mapping and analysis of quantitative trait loci affecting fiber and lignin content in maize.

Plant cell walls of forage provide a major source of energy for ruminant animals. Digestion of cell walls is limited by the presence of lignin, therefore the improving the digestibility of forages by reducing lignin content is a major goal in forage crop breeding programs. A recombinant inbred line maize population was used to map quantitative trait loci (QTL) for neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL) of leaf-sheath and stalk tissues. All traits were positively genetically correlated. The larger genetic correlations were between NDF and ADF in sheaths (r = 0.84), NDF and ADF (r = 0.96), ADF and ADL (r = 0.83), and NDF and ADL (r = 0.76) in stalks. Twelve QTL were detected for NDF and 11 QTL for ADF in leaf-sheaths. Eight QTL detected for both traits were defined by the same or linked marker loci. Eight QTL were associated with leaf-sheath ADL. Eleven QTL were detected for NDF and ADF, and 12 QTL for ADL in stalks. Nine of eleven QTL detected for both NDF and ADF in stalks coincided in their genomic position. A high proportion of QTL detected for these traits had the same parental effects and genomic locations, suggesting that it is only necessary to select on one fiber component (NDF or ADF) to improve digestibility. Favorable correlated responses of unselected fiber components are expected due to coincident genomic locations of QTL and the high genetic correlation between fiber components. Several QTL detected in this study coincided in their positions with putative cellulose synthase genes from maize.

Cell Wall↗

PubMed2003

Lignin degradation in a compost environment by the deuteromycete Paecilomyces inflatus.

Two strains of the deuteromycete Paecilomyces inflatus were isolated from compost samples consisting of municipal wastes, paper and wood chips. Lignin degradation by P. inflatus was studied following the mineralization of a synthetic (14)C(beta)-labeled lignin (side-chain labeled dehydrogenation polymer, DHP). Approximately 6.5% of the synthetic lignin was mineralized during solid-state cultivation of the fungus in autoclaved compost; and 15.5% was converted into water-soluble fragments. Laccase was the only ligninolytic enzyme detectable when the isolates were grown in autoclaved compost. Production of the enzyme was growth-associated and dependent on the culture conditions. The optimal pH for laccase production was between 4.5 and 5.5 and the optimal temperature was around 30 degrees C. Activity levels of laccase increased in the presence of low-molecular-mass aromatic compounds, such as veratryl alcohol, veratric acid, vanillin and vanillic acid.

Benzaldehydes↗

PubMed2006

Early attack and subsequent changes produced in an industrial lignin by a fungal laccase and a laccase-mediator system: an analytical approach.

An industrial kraft pine lignin (Indulin AT, KL) was characterized and treated in both aqueous-buffered media and dioxane to water, either with a partially purified laccase from Fusarium proliferatum or with the laccase plus 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic-acid (ABTS) as mediator. The changes in the lignin after different incubation periods were analyzed through the application of high performance liquid chromatography (HPLC), UV-visible (Vis) spectroscopy and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). At the onset of incubation, laccase-treated samples showed a slight polymerization and strong modifications in UV-Vis spectra. Through Py-GC/MS, a decrease in phenolic and methoxy-bearing pyrolysis products was observed, in contrast to an increase in the more oxidized products. After longer incubation periods (48 h) a substantial polymerization was detected by HPLC, along with a decrease in the guaiacyl (G) units. In contrast, the analysis by HPLC of the samples recovered from the laccase-ABTS system (LMS) showed an intense depolymerization, accompanied by a sizeable loss in G units and a decrease in the methyl and ethyl side-chain phenolic compounds. These results provide conclusive evidence of a rapid initial attack of the industrial lignin by laccase and notable modifications in the KL after longer incubation periods with laccase or LMS.

Benzothiazoles↗

PubMed2005

Does lignin modification affect feeding preference or growth performance of insect herbivores in transgenic silver birch (Betula pendula Roth)?

Transgenic silver birch (Betula pendula Roth) lines were produced in order to modify lignin biosynthesis. These lines carry COMT (caffeate/5-hydroxyferulate O-methyltransferase) gene from Populus tremuloides driven by constitutive promoter 35S CaMV (cauliflower mosaic virus) or UbB1 (ubiquitin promoter from sunflower). The decreased syringyl/guaiacyl (S/G) ratio was found in stem and leaf lignin of 35S CaMV-PtCOMT transgenic silver birch lines when compared to non-transformed control or UbB1-PtCOMT lines. In controlled feeding experiments the leaves of transgenic birch lines as well as controls were fed to insect herbivores common in boreal environment, i.e., larvae of Aethalura punctulata, Cleora cinctaria and Trichopteryx carpinata (Lepidoptera: Geometridae) as well as the adults of birch leaf-feeding beetles Agelastica alni (Coleoptera: Chrysomelidae) and Phyllobius spp. (Coleoptera: Curculionidae). The feeding preferences of these herbivores differed in some cases among the tested birch lines, but these differences could not be directly associated to lignin modification. They could as well be explained by other characteristics of leaves, either natural or caused by transgene site effects. Growth performance of lepidopteran larvae fed on transgenic or control leaves did not differ significantly.

Animals↗

PubMed2006

Degradation of lignin-containing materials by xylanase in biopreparation of cotton.

Solubilization of lignin and carbohydrates from the lignin-holocellulose structure of cotton seed-coat fragments was investigated by UV/VIS spectrometry. Xylanase (Pulpzyme HC) pre-treatment partially destroyed the lignocellulosic structure of the seed-coat fragments, producing reducing sugars and soluble lignin in the supernatant. Furthermore, the pre-treatment by enzyme enhanced the delignification in the subsequent alkaline scouring process and increased the lightness of the substrate.

Biotechnology↗

PubMed1991

Isoelectric focusing electrophoresis of lignin.

Isoelectric focusing is introduced as a technique for the analysis of macromolecular lignin. The analysis is performed in a pH gradient from 3.5 to 10. Separated lignin fragments are visualized under uv light or by silver staining. The method can be used to distinguish between differently processed lignin preparations and to identify their components. Even the slight modification resulting from attack by ligninolytic enzymes could be detected.

Electrophoresis, Polyacrylamide Gel↗

PubMed1983

An extracellular H2O2-requiring enzyme preparation involved in lignin biodegradation by the white rot basidiomycete Phanerochaete chrysosporium.

An H2O2-requiring enzyme system was found in the extracellular medium of ligninolytic cultures of Phanerochaete chrysosporium. The enzyme system generated ethylene from 2-keto-4-thiomethyl butyric acid (KTBA), and oxidized a variety of lignin model compounds including the diarylpropane 1-(4'-ethoxy-3'-methoxyphenyl) 1,3-dihydroxy-2-(4"-methoxyphenyl)propane (I), a beta-ether dimer 1-(4'-ethoxy-3'-methoxyphenyl)glycerol-beta-guaiacyl ether (IV) and an olefin 1-(4'-ethoxy-3'-methoxyphenyl)1,2-propene (VI). The products found were equivalent to the metabolic products previously isolated from intact ligninolytic cultures. In addition, the enzyme system partially degraded 14C-ring labeled lignin. The enzyme was not found in high nitrogen (N) cultures, nor in cultures of a ligninolytic mutant strain which is incapable of metabolizing lignin.

Basidiomycota↗

PubMed1984

The C-C bond cleavage of a lignin model compound, 1,2-diarylpropane-1,3-diol, with a heme-enzyme model catalyst tetraphenylporphyrinatoiron(III)chloride in the presence of tert-butylhydroperoxide.

The catalytic C-C bond cleavage of a lignin model compound was investigated by use of tetraphenylporphyrinatoiron(III)chloride as a model for enzymic degradation of lignin. The C-C bond of the lignin model compound 1,2-bis(4-ethoxy-3-methoxyphenyl) propane-1,3-diol was oxidatively cleaved by catalysis of iron-porphyrins in the presence of tert-butylhydroperoxide or iodosylbenzene at a room temperature. The products formed after complete oxidation of the substrate were identified as 4-O-ethylvanillin, alpha-hydroxy-4-ethoxy-3-methoxyacetophenone, 4-O-ethylvanillic acid, 4-ethoxy-3-methoxyphenylglycol, 4-ethoxy-3-methoxy-alpha-(4-ethoxy-3-methoxyphenyl)-beta-hydroxypropi ophenone and formaldehyde.

Chemical Phenomena↗

PubMed1990

Oxidation of non-phenolic substrates. An expanded role for laccase in lignin biodegradation.

In the presence of substrates such as Remazol Blue and 2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonate) (ABTS), laccases Coriolus (Trametes) versicolor can also oxidize non-phenolic lignin model compounds. Veratryl alcohol (I) and 1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)-propane-1,3-diol (III) were oxidized by laccase and mediator to give the alpha-carbonyl derivatives. The beta-1 lignin model dimer, 1-(3,4-dimethoxyphenyl)-2-phenoxy-ethane-1,2-diol (II) was cleaved by laccase in the presence of ABTS to give veratraldehyde and benzaldehyde. On the basis of these observations, we propose that laccase is capable of oxidizing both phenolic and non-phenolic moieties of lignin but that the latter is dependent on the co-presence of primary laccase substrates.

Benzyl Alcohols↗

PubMed2004

Growth of Azotobacter vinelandii in a solid-state fermentation of technical lignin.

Azotobacter vinelandii was cultured on technical lignin, derived from Kraft pulping processes, for biofertilizer production in solid-state fermentation. The effects of the ratio of technical lignin to corn straw, initial water content, and material bed depth on the microorganisms were studied in detail. At 30 degrees C, technical lignin to corn straw at the ratio of 1:0.75, the bed depth of 5 cm, and 67% moisture content, A. vinelandii was grown and reached 4.2 x 10(10) cfu g(-1) dry rot after 36 h.

Azotobacter vinelandii↗

PubMed2004

Evaluation of Argentinean white rot fungi for their ability to produce lignin-modifying enzymes and decolorize industrial dyes.

The decolorizing capacity of 26 white rot fungi from Argentina was investigated. Extracellular production of ligninolytic enzymes by mycelium growing on solid malt extract/glucose medium supplemented with different dyes (Malachite Green, Azure B, Poly R-478, Anthraquinone Blue, Congo Red and Xylidine), dye decolorization and the relationship between these two processes were studied. Only ten strains decolorized all the dyes, all ten strains produced laccase, lignin peroxidase and manganese peroxidase on solid medium. However, six of the strains could not decolorize any of the dyes; all six strains tested negative for lignin peroxidase, and produced less than 0.05 U/g agar of manganese peroxidase. Comparing the isolates with the well-known dye-degrader Phanerochaete chrysosporium, a new fungus was identified: Coriolus versicolor f. antarcticus, potentially a candidate for use in biodecoloration processes. Eighteen day-old cultures of this fungus were able to decolorize in an hour 28%, 30%, 43%, 88% and 98% of Xylidine (24 mg/l), Poly R-478 (75 mg/l), Remazol Brilliant Blue R (9 mg/l), Malachite Green (6 mg/l) and Indigo Carmine (23 mg/l), respectively. Laccase activity was 0.13 U/ml, but neither lignin peroxidase nor manganese peroxidase were detected in the extracellular fluids for that day of incubation.

Argentina↗

PubMed2006

Reactions, characterization and uptake of ammoxidized kraft lignin labeled with 15N.

Ammoxidation of kraft lignin was carried out in a Parr reactor using (15)NH(3) as the main nitrogen source. Reaction parameters were set up until a total nitrogen content of approximately 13 wt.% in lignin was achieved, in accordance with conditions of previous studies. Analytical tools such as FTIR, Py-GC/MS, and solid state NMR were used in this research. The nature of nitrogen bondings is discussed. The incorporation of the (15)N from ammoxidized lignin was followed in pumpkins (Zucchini cucurbita pepo L.) by means of (15)N emission spectroscopy.

Ammonia↗

PubMed2005

Size-exclusion chromatography of technical lignins in dimethyl sulfoxide/water and dimethylacetamide.

Well defined spent sulfite liquor samples and lignosulfonate fractions obtained by ultrafiltration were analyzed using size-exclusion chromatography. Two different eluent systems (dimethyl sulfoxide/water/lithium bromide; dimethylacetamide/lithium chloride) were compared regarding their suitability for lignin analysis. The differences of the elution profiles and calculated molar masses were discussed using conventional and universal calibration. For further validation four technical lignins from a Round Robin test were included into the study. The results indicated that both analytical systems under investigation were well suited for the analysis of technical lignins.

Acetamides↗

PubMed2005

Incomplete processing of peroxidase transcripts in the lignin degrading fungus Phanerochaete chrysosporium.

Phanerochaete chrysosporium has been thoroughly studied as a microbial model for lignin degradation. The enzymes lignin peroxidase (LiP) and manganese peroxidase (MnP), both encoded by several genes, play the main role in the cleavage of different lignin substructures. In this work, the expression of specific LiP and MnP transcripts in liquid medium and in a wood-containing soil system was studied by reverse transcription-PCR and subsequent cloning and sequencing of the products obtained. Splice variants of different LiP and MnP transcripts were observed in wood-containing soil incubations and in liquid cultures. The processed transcripts contained different numbers of complete introns. Since the presence of stop codons in several of these introns would prevent the synthesis of active enzyme, we propose that these transcripts arise as a result of incomplete processing rather than alternative splicing. Interestingly, analysis of splice variants from mnp genes led to the identification of a fourth actively transcribed gene coding for MnP in P. chrysosporium.

Codon, Terminator↗

PubMed2005

Two isolates of Fusarium proliferatum from different habitats and global locations have similar abilities to degrade lignin.

Two isolates of Fusarium proliferatum from different global locations and habitats mineralized several natural and synthetic lignins. MUCL 31970 was isolated from a forest soil whereas the second strain, NRRL 31071, was a wheat endophyte causing disease in stressed seedlings. Onset and the fastest rate of lignin mineralization occurred during logarithmic and early stationary-phase of culture. Reduction of glucose in the medium shortened log-growth phase and advanced the onset of mineralization for both isolates. Mineralization correlated with the detection of extracellular laccase and aryl alcohol oxidase activities. The carbon-nitrogen ratio in the medium influenced laccase isozyme production and secretion by both strains. These studies suggest that both F. proliferatum strains degrade lignin via comparable routes, despite their different habitats and saprophytic or endophytic strategies.

Alcohol Oxidoreductases↗

PubMed2005

Molecular requirements of lignin-carbohydrate complexes for expression of unique biological activities.

Lignins are major cell wall components formed by the dehydrogenative polymerization of three monolignols, p-coumaryl, coniferyl and sinapyl alcohols. We prepared lignin-carbohydrate complexes (Fr. VI and Fr. VII) from pine cones by acid and ethanol precipitation, and investigated which part of these molecules is essential for expression of biological activities. They showed potent antiviral activity upon direct interaction with the virus. The antiviral activity of Frs. VI and VII required the higher-order structure of polyphenols without polysaccharides. Pretreatment of mice with Fr. VI or VII induced higher antiparasite activity than those of natural and chemically modified antitumor polysaccharides. Fr. VI or VII at higher concentrations enhanced the radical intensity and cytotoxic activity of vitamin C, whereas tannins counteracted the effect of vitamin C. Fr. VI at lower concentrations enhanced the O2(-)-scavenging activity of vitamin C. Frs. VI and VII stimulated mouse macrophage-like cells Raw 264.7 to produce nitric oxide (NO), citrulline (CIT) and asparagine (ASN), via the enhanced expression of iNOS and ASN synthetase, whereas phenylpropenoid monomers and polymers inhibited NO/CIT/ASN production. These data suggest that the polymerized structure of phenylpropenoids in lignin-carbohydrate complexes is required for the induction of antiviral activity, and that the higher-order structure of phenylpropenoid polymers and polysaccharides is required for immunopotentiation, including macrophage activation.

Animals↗