• Journal of the Korean Wood Science and Technology
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• v.23 no.4
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• pp.108-116
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• 1995

This experiment was conducted to screen a superior wood-rotting fungi for lignin degradation and ligninolytic enzyme production by evaluation of red colored zone width on potato-dextrose agar medium and oak woodmeal medium complimented guaiacol. Relationship between the red colored zone width on GU-WA medium and klason lignin loss on woodmeal medium showed the positive correlation. Thus, the potential ligninolytic activity of wood rotting fungi which are not elucidated yet may be estimated to some extent by the evaluation of the red colored zone width on GU-WA medium. Of the isolates screened from fruit bodies and decayed woods. LKY-12, LKY-7 and C. versicolor-13 isolates having preferential lignin degradation and laccase activity were selected. These isolates exhibited characteristics of superior wood-rotting fungi as Klason lignin loss ranged from 30% to 35% and ligninolytic enzyme activity of these isolates on glucose-peptone broth was higher than that of other isolates. And then, these isolates were considered to be able to use in biological pulping and bleaching and ligninolytic enzyme production.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.38 no.5 s.118
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• pp.1-8
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• 2006

This study was performed to evaluate extensive electrochemical characteristics of 23 commercially available mediators for laccase. Electrochemical properties, interactions with laccases, and ability to degrade lignin were compared for selected mediators. Among them, NNDS has very similar electrochemical properties in terms of reversibility and redox potential (about 470 mV vs. Ag/AgCl at pH=7) compared to ABTS which is a well-known mediator. Specific activity of purified laccase from Cerrena unicolor was determined by both 2,2'-azino-bis-(3-ethylbenz-thiazoline-6-sulfonic acid) (ABTS) and 1-nitroso-2-naphthol -3,6-disulfonic acid (NNDS). The specific activity of the laccase was 23.2 units/mg with ABTS and 21.2 units/mg with NNDS. The electron exchange rate for NNDS with laccase was very similar to that for ABTS, which meant that NNDS had similar mediating capability to ABTS. Determining methanol concentration after reacting with laccase compared to lignin degradation capabilities of both ARTS and NNDS. ARTS or NNDS alone cannot degrade lignin, but in the presence of laccase enhanced the rate of lignin degradation. ABTS showed better activity in the beginning, and the reaction rate of NNDS with lignin was about a half of that of ABTS at 10 minute, but the final concentration of methanol produced in 1 hour was very similar each other. The reason for similar methanol concentration for both ABTS and NNDS can be interpreted as the initial activity of ABTS was better than that of NNDS, but ABTS would be inhibited laccase activity more during the incubation.

• Environmental Engineering Research
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• v.23 no.3
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• pp.294-300
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• 2018

Cometabolism technology was employed to degrade lignin wastewater in Sequencing Batch Biofilm Reactor. Cometabolic system (with glucose and lignin in inflow) and the control group (only lignin in inflow) were established to do a comparative study. In contrast with the control group, the average removal rates of lignin increased by 14.7% and total oarganic carbon increased by 32% in the cometabolic system with glucose as growth substrate, under the condition of 5 mg/L DO, $0.2kgCOD/(m^3{\cdot}d)$ lignin and glucose $1.0kgCOD/(m^3{\cdot}d)$. Functional groups of lignin are degraded effectively in cometabolic system proved by fourier transform infrared spectroscopy and Gas Chromatography-Mass Spectrometer, and the degradation products were amides (mainly including acetamide, N-ethylacetamide and N, N-diethylacetamide), alcohols (mainly including glycerol and ethylene glycol) and acids. Meanwhile, results of Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis showed great differences in microbial population richness between cometabolic system and the control group. The Margalef's richness index and Shannon-Wiener's diversity index of microorganism in cometabolic system were 3.075 and 2.61, respectively. The results showed that extra addition of glucose, with a concentration of 943 mg/L, was beneficial to lignin biodegradation in cometabolic system.

• Journal of the Korean Wood Science and Technology
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• v.31 no.6
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• pp.31-39
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• 2003

The enzymatic isolation of residual lignins obtained from spruce and beech pulps (obtained by sulfite, kraft, ASAM and soda/AQ/MeOH pulping processes) and their characterization was described in previous publications. Here, the residual lignins have been submitted to potassium permanganate oxidation (KMnO₄ degradation), and 9 aromatic carboxylic acids (3 of them are dimeric) were identified after methylation with diazomethane by GC/MS. The analytical challenge during qantification by the internal standard methods was the partly high protein content of the samples, which resulted in elevated anisic acid yields in the degradation mixture of sulfite residual lignins. The results are compared with the KMnO₄ degradation of the corresponding MWLs and discussed in terms of S/G ratios and degrees of condensation. The latter was calculated as a quotient between the aromatic carboxylic acids derived from condensed and non-condensed lignin structures. Typical degradation patterns for the various processes have been observed. Among other parameter, the relative compositions between iso-hemipinic acid (which is for condensation in pos. 5 of the aromatic ring) and meta-hemipinic acid and 3,4,5-trimethoxyphthalic acid (both are for condensation in pos. 6 of the aromatic ring) was found to be process specific. Kraft and soda/AQ/MeOH residual lignins yielded higher amounts of iso-hemipinic acid. In contrast, the relative yields of meta-hemipinic acid and 3,4,5-trimethoxyphthalic acid (the latter in beech lignins) are higher in sulfite and particularly in ASAM residual lignin. In case of beech residual lignins the amount of acids originated from non-condensed syringyl type lignin units was surprisingly high. The condensation degree of residual lignins was shown to be generally higher than that of MWLs. This was especially true for the G units. ASAM residual lignin exhibited very high S/G ratios and degrees of polymerization. Causality between condensation degree and total yield of degradation products was demonstrated.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.473-476
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• 2002

A lignin degradation bacteria, symbiotic bacteria was isolated from the gut of Sympetrum depressiusculum and tested for its lignin degrading activity using lignin model compounds and related aromatic compounds. The strain was identified as Serratia marcescens HY-5 based on the 165 rDNA, cellular fatty acid composition, biochemical and physiological characteristics. S. marcescens showed 40-50% lignin degrading activity in the media that contained vaillin, guaiacol and dealkaline lignin. S. marcescens showed three ligninase activities [Jaccase, lignin peroxidase(LiP) and Manganase peroxidase(MnP)]. Addition of dealkaline lignin to the basal media increased about 6fold of laccase activity. Vanillic acid or vanillin increase 1.3fold of MnP activity and p-coumaric acid increased 12fold of LiP activity which added to the basal medium.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.5
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• pp.1-11
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• 1999

Wood components, cellulose and lignin, are degraded simultaneously and the general outline for the complementary character of carbohydrates and lignin decomposition as well as the existence of enzymatic systems combining these processes is still valid. The degradatiion of free cellulose or hemicellulose into monosaccharides has long been known to be relatively simple, but the mechanism of lignin degradatiion wasn ot solved very clearly yet. Anyway the biodegradation of woold constituents is understood at present as an enzymatic process. Kigninolytic activity has been correlated with lignin and manganese peroxidases. At present the attention is paid to laccase. Laccase oxidizes lignin molecule to phenoxy radicals and quinones . This oxidation can lead to the cleavageo f C-C or C-O bonds in the lignin phenyl-propane subunits, resulting either in degradation of both side chains and aromatic rings, or in demethylation processes. The role of laccase lies in the "activation" of some low molecular weight mediators and radicals produced by fungal cultures. Such activated factors produced also in cooperation with other enzymes are probably exported to the wood environment where they work in degradation processes as the ' enzyme messengers." It is worth mentioning that only fungi possessing laccase show demethylating activity. Thus demethylation, the process important for ligninolysis, is probably caused exclusively by laccase. Under natural conditions laccase seems to work with other fungal enzymes , mediators and mediating radicals. It has shown the possibility of direct Bjrkman lignin depolymerization by cooperative activity of laccase and glucose oxidase.

• Journal of the Korea Organic Resources Recycling Association
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• v.15 no.4
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• pp.131-137
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• 2007

In this study, the biodegradation test on lignocellulose under sulfate reducing conditions was carried out. In particular, the interaction between cellulose and lignin was investigated with various g-cellulose/g-lignin (C/L) ratios: 42.15, 4.59, 2.51, 1.14 and 0.7. It was shown that the rate of cellulose degradation decreased in proportion to the lignin content. Assuming first order degradation kinetics, the consequences of competitive inhibition were graphically shown for different C/L ratios. The relation between cellulose reduction rate and C/L ratio was expressed by logarithm function with a determination coefficient of 0.97. Lignocellulose reduction rate was also described as a logarithm function of C/L ratio showing a inhibition effect by lignin. In the mean time, the rate of lignin decomposition was higher at C/L ratio of 2.51 and 1.14 compared with C/L ratios of 4.59 and 0.7, indicating that excessive extra carbon source is not appropriate for lignin biodegradation.

• Journal of Life Science
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• v.12 no.4
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• pp.392-398
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• 2002

38 strains were isolated in order to utilize lignin degrading ability from soil and compost. A organism having high lignin degrading ability of the isolated strains determined morphologcal and biochemical characteristics. Enrichment technique yielded a lignin degrading bacterium characterized as Pseudomonas sp. LC-2. This strain was able to degrade lignin which are the true representatives of native lignin and transform lignin to a lot of aromatic compounds as HPLC analysis of culture. By polyacrylamide gel analysis, it was determined that peroxidase consisted of three enzymes, with only one, the lignin peroxidase having high activity.

• Environmental Engineering Research
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• v.24 no.4
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• pp.670-679
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• 2019

Lignin complexity molecule makes its biodegradation difficult during lignocellulosic wastes composting. So, the improvement of its biodegradation has usually been considered as an objective. This study aimed to determine the impact of Trametes trogii inoculation on organic matter and particularly on lignin and cellulose during green wastes co-composting with olive mill waste water sludge and coffee grounds. Three types of heaps (H1, H2 and H3) were investigated during 180 d. H3 and H2 were inoculated at the beginning of the process (t₀) and 120 d later (t₁₂₀), respectively while H1 was the control. Results showed the absence of pH stabilization in H3 during the first month. Also, in this period we observed a faster degradation of some easily available organic matter in H3 than in the other heaps. After 120 d, a better cellulose decomposition (25.28%) was noticed in H3 than in H1 and H2 (16%). Inoculation during the second fermentation phase induced supplementary lignin degradation in H2 with a percentage of 35% against 23 and 26% for H1 and H3, respectively. For all the runs, a Fourier Transform Infrared analysis showed aliphatic groups' decrease, OH groups' increase and lignin structural modification.

• KSBB Journal
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• v.13 no.3
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• pp.223-230
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• 1998

Experiments for lignin peroxidase production have been conducted by aerobic fermentation of Phanerochaete chrysosporium under low shear rate and enriched oxygen environment. The result of flask cultures of white rot fungus indicated that high oxygen concentration and low shear force were essential for enhancement of lignin peroxidase production. Pentachlorophenol was readily degraded by lignin peroxidase produced in nutrient limited flask cultures. Polyurethane foam was fond to be an effective immobilization matrix of P. chrysosporium.