Trametes suaveolens as ligninolytic enzyme producer

Species of the genus Trametes represent one of the most efficient lignin-degraders which can be attributed to a well developed ligninolytic enzyme system. Current trends are screening of ability of new species to produce these enzymes, as well as the optimization of conditions for their overproduction. Therefore, the aim of the study was to evaluate the potential of T. suaveolens to synthesize laccase and Mn-oxidizing peroxidases during fermentation of the selected plant raw materials. Level of enzyme activities was measured on 7, 10 and 14th day of submersion, as well as the solid-state fermentation of wheat straw and oak sawdust in the presence of NH4NO3 in previously determined optimal nitrogen concentration of 25 mM. The enzyme activity was determined spectrophotometrically using ABTS and phenol red as the substrates. The highest level of laccase activity (1087.1 U/L) was noted after 7 days of wheat straw solid-state fermentation, while during the submerged cultivation the production of the enzyme was not noted. Submerged cultivation in oak sawdust-enriched medium was the optimal for activity of Mn-dependent peroxidase (1767.7 U/L on day 14) and Mn-independent peroxidase (1113.7 U/L on day 7). Introduction of T. suaveolens to produce ligninolytic enzyme represented the base for further study, as well as the determination of relation between enzyme activity and rate of lignin degradation. It could lead to greater possibility of fungal species selection with high delignification capacity, which could take participation in sustainable production of food, feed, fibres, and energy, environmentally friendly pollution prevention, and bioremediation.

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Ligninolytic enzyme production by Lenzites betulinus on selected plant raw materials

Zbornik Matice srpske za prirodne nauke ◽

10.2298/zmspn1120333k ◽

2011 ◽

pp. 333-338

Author(s):

Aleksandar Knezevic ◽

Ivan Milovanovic ◽

Mirjana Stajic ◽

Jelena Vukojevic

Keyword(s):

Solid State ◽

Wheat Straw ◽

Solid State Fermentation ◽

Peroxidase Activity ◽

Submerged Fermentation ◽

Laccase Activity ◽

Raw Materials ◽

Carbon Sources ◽

Ligninolytic Enzyme ◽

Plant Residues

To get a better insight into the ligninolytic system of Lenzites betulinus, the effect of wheat straw and oak sawdust, as carbon sources, on production of Mn-oxidizing peroxidases and laccase, under solid-state and submerged fermentation, was studied. Obtained results revealed considerable differences related to the both factors affecting enzyme activities. Wheat straw was more favorable carbon source for Mn-oxidizing peroxidases and oak sawdust for laccase activity. Solid-state fermentation of wheat straw was optimal for Mn-dependent peroxidase activity (72.1 Ul-1). In contrary to this, submerged fermentation of the same residue gave the highest level of versatile peroxidase activity (25.4 Ul-1). The peak of laccase activity was noted during solid-state fermentation of oak sawdust (32.3 Ul-1), while this enzyme was not detected under submerged fermentation of any plant residues.

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Production of Manganese Peroxidase and Organic Acids and Mineralization of 14C-Labelled Lignin (14C-DHP) during Solid-State Fermentation of Wheat Straw with the White Rot Fungus Nematoloma frowardii

Applied and Environmental Microbiology ◽

10.1128/aem.65.5.1864-1870.1999 ◽

1999 ◽

Vol 65 (5) ◽

pp. 1864-1870 ◽

Cited By ~ 99

Author(s):

Martin Hofrichter ◽

Tamara Vares ◽

Mika Kalsi ◽

Sari Galkin ◽

Katrin Scheibner ◽

...

Keyword(s):

Solid State ◽

Organic Acids ◽

Wheat Straw ◽

Solid State Fermentation ◽

Manganese Peroxidase ◽

Ligninolytic Enzyme ◽

Water Soluble ◽

White Rot ◽

White Rot Fungus ◽

Free System

ABSTRACT The basidiomycetous fungus Nematoloma frowardiiproduced manganese peroxidase (MnP) as the predominant ligninolytic enzyme during solid-state fermentation (SSF) of wheat straw. The purified enzyme had a molecular mass of 50 kDa and an isoelectric point of 3.2. In addition to MnP, low levels of laccase and lignin peroxidase were detected. Synthetic 14C-ring-labelled lignin (14C-DHP) was efficiently degraded during SSF. Approximately 75% of the initial radioactivity was released as14CO2, while only 6% was associated with the residual straw material, including the well-developed fungal biomass. On the basis of this finding we concluded that at least partial extracellular mineralization of lignin may have occurred. This conclusion was supported by the fact that we detected high levels of organic acids in the fermented straw (the maximum concentrations in the water phases of the straw cultures were 45 mM malate, 3.5 mM fumarate, and 10 mM oxalate), which rendered MnP effective and therefore made partial direct mineralization of lignin possible. Experiments performed in a cell-free system, which simulated the conditions in the straw cultures, revealed that MnP in fact converted part of the14C-DHP to 14CO2 (which accounted for up to 8% of the initial radioactivity added) and14C-labelled water-soluble products (which accounted for 43% of the initial radioactivity) in the presence of natural levels of organic acids (30 mM malate, 5 mM fumarate).

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Fibre degradation of wheat straw by Pleurotus erygnii under low moisture conditions during solid-state fermentation

Letters in Applied Microbiology ◽

10.1111/lam.13104 ◽

2019 ◽

Vol 68 (2) ◽

pp. 182-187 ◽

Cited By ~ 1

Author(s):

P.W. Baker ◽

A. Charlton ◽

M.D.C. Hale

Keyword(s):

Solid State ◽

Wheat Straw ◽

Solid State Fermentation ◽

Fibre Degradation ◽

Moisture Conditions

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Ligninolytic enzyme production in Pleurotus eryngii depending on the medium composition and cultivation conditions

Zbornik Matice srpske za prirodne nauke ◽

10.2298/zmspn0508269s ◽

2005 ◽

pp. 269-276

Author(s):

Mirjana Stajic ◽

Sonja Duletic-Lausevic ◽

Jelena Vukojevic

Keyword(s):

Nitrogen Concentration ◽

Nitrogen Sources ◽

Ligninolytic Enzyme ◽

Medium Composition ◽

Pleurotus Eryngii ◽

Phenol Red ◽

Cultivation Conditions ◽

Carbon And Nitrogen Sources ◽

Carbon And Nitrogen ◽

Two Peaks

Pleurotus eryngii produced laccase (Lac) both under conditions of submerged fermentation (SF) and solid-state fermentation (SSF) using all of the investigated carbon and nitrogen sources, while significant peroxidases production occurred only under SSF conditions. The highest levels of Lac activity were found under SF conditions of dry ground mandarine peels (999.5 U/l). After purification of extracellular crude enzyme mixture of P. eryngii which was grown under SF conditions with dry ground mandarine peels it was revealed two peaks of Lac activity and one peak of activity against phenol red in absence of external Mn2+ which was very low (1.4 U/l). Results obtained by purification also showed that the levels of phenol red oxidation in absence of external Mn2+ were higher than phenol red oxidation levels in presence of external Mn2+. In the medium with the best carbon source for Lac production (dry ground mandarine peels), (NH4)2SO4, with a nitrogen concentration of 20 mM, was the most optimum nitrogen source among 8 investigated sources.

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