Novel Scheme for Biosynthesis of Aryl Metabolites from l-Phenylalanine in the FungusBjerkandera adusta

ABSTRACT Aryl metabolite biosynthesis was studied in the white rot fungusBjerkandera adusta cultivated in a liquid medium supplemented with l-phenylalanine. Aromatic compounds were analyzed by gas chromatography-mass spectrometry following addition of labelled precursors (14C- and 13C-labelledl-phenylalanine), which did not interfere with fungal metabolism. The major aromatic compounds identified were benzyl alcohol, benzaldehyde (bitter almond aroma), and benzoic acid. Hydroxy- and methoxybenzylic compounds (alcohols, aldehydes, and acids) were also found in fungal cultures. Intracellular enzymatic activities (phenylalanine ammonia lyase, aryl-alcohol oxidase, aryl-alcohol dehydrogenase, aryl-aldehyde dehydrogenase, lignin peroxidase) and extracellular enzymatic activities (aryl-alcohol oxidase, lignin peroxidase), as well as aromatic compounds, were detected in B. adusta cultures. Metabolite formation required de novo protein biosynthesis. Our results show that l-phenylalanine was deaminated to trans-cinnamic acid by a phenylalanine ammonia lyase and trans-cinnamic acid was in turn converted to aromatic acids (phenylpyruvic, phenylacetic, mandelic, and benzoylformic acids); benzaldehyde was a metabolic intermediate. These acids were transformed into benzaldehyde, benzyl alcohol, and benzoic acid. Our findings support the hypothesis that all of these compounds are intermediates in the biosynthetic pathway froml-phenylalanine to aryl metabolites. Additionally,trans-cinnamic acid can also be transformed via β-oxidation to benzoic acid. This was confirmed by the presence of acetophenone as a β-oxidation degradation intermediate. To our knowledge, this is the first time that a β-oxidation sequence leading to benzoic acid synthesis has been found in a white rot fungus. A novel metabolic scheme for biosynthesis of aryl metabolites froml-phenylalanine is proposed.

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Aryl-alcohol oxidase and lignin peroxidase from the white-rot fungus Bjerkandera adusta

Journal of Biotechnology ◽

10.1016/0168-1656(90)90101-g ◽

1990 ◽

Vol 13 (2-3) ◽

pp. 159-167 ◽

Cited By ~ 40

Author(s):

Andreas Muheim ◽

Matti S.A. Leisola ◽

Hans E. Schoemaker

Keyword(s):

Lignin Peroxidase ◽

Alcohol Oxidase ◽

White Rot ◽

White Rot Fungus ◽

Bjerkandera Adusta

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The Onset of Lignin-Modifying Enzymes, Decrease of AOX and Color Removal by White-Rot Fungi Grown on Bleach Plant Effluents

Water Science & Technology ◽

10.2166/wst.1991.0475 ◽

1991 ◽

Vol 24 (3-4) ◽

pp. 189-198 ◽

Cited By ~ 37

Author(s):

V. P. Lankinen ◽

M. M. Inkeröinen ◽

J. Pellinen ◽

A. I. Hatakka

Keyword(s):

Lignin Peroxidase ◽

Active Form ◽

White Rot Fungi ◽

Pulp Mill ◽

Color Removal ◽

Effluent Treatment ◽

White Rot ◽

White Rot Fungus ◽

Lignin Peroxidases ◽

Pulp Mill Effluents

Decrease of adsorbable organic chlorine (AOX) is becoming the most important criterion for the efficiency of pulp mill effluent treatment in the 1990s. Two methods, designated MYCOR and MYCOPOR which utilize the white-rot fungus Phanerochaete chrysosporium have earlier been developed for the color removal of pulp mill effluents, but the processes have also a capacity to decrease the amount of chlorinated organic compounds. Lignin peroxidases (ligninases) produced by P. chrvsosporium may dechlorinate chlorinated phenols. In this work possibilities to use selected white-rot fungi in the treatment of E1-stage bleach plant effluent were studied. Phlebia radiata. Phanerochaete chrvsosporium and Merulius (Phlebia) tremellosus were compared in shake flasks for their ability to produce laccase, lignin peroxidase(s) and manganese-dependent peroxidase(s) and to remove color from a medium containing effluent. Softwood bleaching effluents were treated by carrier-immobilized P. radiata in 2 1 bioreactors and a 10 1 BiostatR -fermentor. Dechlorination was followed using Cl ion and AOX determinations. All fungi removed the color of the effluent. In P. radiata cultivations AOX decrease was ca. 4 mg l−1 in one day. Apparent lignin peroxidase activities as determined by veratryl alcohol oxidation method were negligible or zero in a medium with AOX content of ca. 60 mg l−1, prepared using about 20 % (v/v) of softwood effluent. However, the purification of extracellular enzymes implied that large amounts of lignin peroxidases were present in the medium and, after the purification, in active form. Enzyme proteins were separated using anion exchange chromatography, and they were further characterized by electrophoresis (SDS-PAGE) to reveal the kind of enzymes that were present during AOX decrease and color removal. The most characteristic lignin peroxidase isoenzymes in effluent media were LiP2 and LiP3.

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Identification of white rot fungus CP9 and its potential application in biopulping

Vietnam Journal of Biotechnology ◽

10.15625/1811-4989/14/4/12306 ◽

2018 ◽

Vol 14 (4) ◽

pp. 721-726

Author(s):

Nguyen Thi Hong Lien ◽

Nguyen Van Hieu ◽

Luong Thi Hong ◽

Hy Tuan Anh ◽

Phan Thi Hong Thao

Keyword(s):

Rice Straw ◽

Lignin Peroxidase ◽

Paper Industry ◽

Morphological Characteristics ◽

White Rot Fungi ◽

White Rot ◽

White Rot Fungus ◽

Wood Block ◽

New Production ◽

Cellulosic Fibers

Wood-rotting fungi represent an important component of forest ecosystems. Among them, white-rot fungi are the most efficient lignin degraders. Biopulping using white-rot fungi in pretreatment of the materials, is one of the solutions to overcome disadvantages of traditional production methods. Today, the isolation and screening of lignin degrading fungi capable for application in biopulping are of keen interest in Vietnam. The use of non–wood, plant fibres in pulp and paper industry, special, agricultural residuces such as rice and wheat straw, sugarcane baggase, cornstalks etc is the new production toward, potential, serving sustainable development. The fungus CP9, which possessed high ligninolytic activity, was identified and studied in pretreatment of rice straw for biopulping. The fruiting bodies of strain CP9 were effuse on trunk. The hymenium was porous and brown white with short tubes, the white mycelia penetrated wood block. The colony was off-white, blossom, irregularly circular. The mycelia were thick and closely bound together. Beside lignin, this fungus could degrade other substrates such as casein, carboxymethyl cellulose and starch. Biological and morphological characteristics of the fungus CP9 suggested its placement in subdivision Basidiomycota. Combined with the results of phylogenetic analysis, which showed 99% similarity of the fungus with species Leiotrametes lactinea, our strain was named as Leiotrametes lactinea CP9. This fungus could grow well on rice straw under solid state fermentation. Pretreatment of rice straw using L. lactinea CP9 was based on the activity of fungal lignin peroxidase and laccase. After 20 days, the residual enzyme activity was of 21.6 and 18.4 nkat/g material for lignin peroxidase and laccase, respectively. Pretreatment significantly improved the quality of straw, as lignin loss of 38% while cellulosic fibers were comparatively well preserved.

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