Aims: Laccase is a blue copper oxidase that catalyses four electron reduction of molecular oxygen to water. It is able to oxidise aromatic compounds with molecular oxygen as the terminal electron acceptor. The aim of this study was to screen for laccase producing basidiomycetes isolated from decaying woods and tree trunks around Kampar, Perak. Methodology and results: The isolated basidiomycetes were screened for their laccase activity on different agar plates supplemented with 2, 2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), guaiacol and Remazol Brillant Blue R (RBBR), respectively. In the presence of laccase, the colourless ABTS and guaiacol were oxidised to form blue-green and reddish-brown coloured zone around the fungal colony, respectively; whereas the blue RBBR was decolourised by the enzyme. Colour or colourless halo zones that are formed on the agar plates indicate the presence of ligninolytic enzyme activities. Isolates KA1 and TR9 indicated the highest enzymatic hydrolysis on ABTS plates with the halo zone ratio of 1.43  0.04 and 0.98  0.01, respectively. Based on the BLAST results from the amplicon of ITS1 and ITS4 primers, Isolates KA1 and TR9 were identified as Trametes lactinea and Pycnoporous coccineus, respectively. Under submerged fermentation, P. coccineus has higher laccase production (0.72 U/mL) compared with T. lactinea (0.16 U/mL). Conclusion, significance and impact of study: Both T. lactinea and P. coccineus are potential strains for laccase production which can be used for dye decolourisation and degradation. Future studies will focus on the application of the laccase in textile dye degradation.
Laccase

Pitch deposits have negative effects on product quality, machine performance and production line profitability during pulp and paper manufacture. As traditional pitch control technology cannot provide satisfactory solutions in the pitch deposits, the enzymatic treatment has been rapidly developed for its high efficiency and pollution-free property. In this review, the chemical composition and present form of the pitch in pulp is first introduced, followed by a description of the pitch control enzymes. The emphasis is on the current research on enzymatic solutions to pitch problems, including the reaction mechanism, technology, and the present main problems of lipase, sterol esterases, laccase and lipoxygenase. Finally, the technology prospects in this field are proposed.
Laccase ; Lipase ; Lipoxygenase ; Paper

Laccase is one of the most important oxidoreductase with industrialization potential. However, due to the high cost and catalytic toxicity of laccase synthetic mediator, the laccase-mediator-system still cannot achieve industrialization. Therefore, searching for high efficient, environment-friendly, and cheap natural mediator from small molecule precursors or intermediates and degradation products of lignin has been considered as a hot research topic. Therefore, we introduce the type and catalytic mechanism of laccase mediator, the composition and separation of natural laccase mediator from water washed solution of steam exploded straw, black liquor and lignocelluloses degradation products during the fermentation of white-rot fungi. We also provide the theoretical and technical direction for exploring of high reactive of laccase natural mediators and achieving the oriented high-value utilization of lignocellulose degradation products.
Basidiomycota ; Fermentation ; Laccase ; chemistry ; Lignin ; chemistry ; Steam

Two white rot fungi, Ceriporia sp. ZLY-2010 (CER) and Stereum hirsutum (STH) were used as biocatalysts for the biotransformation of (-)-alpha-pinene. After 96 hr, CER converted the bicyclic monoterpene hydrocarbon (-)-alpha-pinene into alpha-terpineol (yield, 0.05 g/L), a monocyclic monoterpene alcohol, in addition to, other minor products. Using STH, verbenone was identified as the major biotransformed product, and minor products were myrtenol, camphor, and isopinocarveol. We did not observe any inhibitory effects of substrate or transformed products on mycelial growth of the fungi. The activities of fungal manganese-dependent peroxidase and laccase were monitored for 15 days to determine the enzymatic pathways related to the biotransformation of (-)-alpha-pinene. We concluded that a complex of enzymes, including intra- and extracellular enzymes, were involved in terpenoid biotransformation by white rot fungi.
Biotransformation* ; Camphor ; Enzymes ; Fungi* ; Laccase ; Peroxidase

A newly isolated white rot fungal strain KU-RNW027 was identified as Trametes polyzona, based on an analysis of its morphological characteristics and phylogenetic data. Aeration and fungal morphology were important factors which drove strain KU-RNW027 to secrete two different ligninolytic enzymes as manganese peroxidase (MnP) and laccase. Highest activities of MnP and laccase were obtained in a continuous shaking culture at 8 and 47 times higher, respectively, than under static conditions. Strain KU-RNW027 existed as pellets and free form mycelial clumps in submerged cultivation with the pellet form producing more enzymes. Fungal biomass increased with increasing amounts of pellet inoculum while pellet diameter decreased. Strain KU-RNW027 formed terminal chlamydospore-like structures in cultures inoculated with 0.05 g/L as optimal pellet inoculum which resulted in highest enzyme production. Enzyme production efficiency of T. polyzona KU-RNW027 depended on fungal pellet morphology as size, porosity, and formation of chlamydospore-like structures.
Biomass ; Laccase ; Manganese ; Peroxidase ; Porosity ; Trametes*

Components separation is the key technology in biorefinery. Combination of steam explosion and laccase was used, and synergistic effect of the combined pretreatment was evaluated in terms of physical structure, chemical components and extraction of lignin. The results showed that steam explosion can destroy the rigid structure and increase the specific surface area of straw, which facilitated the laccase pretreatment. The laccase pretreatment can modify the lignin structure based on the Fourier transform infrared test, as a result the delignification of straw was enhanced. Nuclei Growth model with a time dependent rate constant can describe the delignification, and the kinetics parameters indicated that the combined pretreatment improved the reaction sites and made the delignification reaction more sensitive to temperature. The combined pretreatment enhanced delignification, and can be a promising technology as an alternative to the existing pretreatment.
Biotechnology ; methods ; Laccase ; chemistry ; Lignin ; chemistry ; Plant Stems ; chemistry ; Steam

Laccase activity of Pleurotus ostreatus is significantly increased by the addition of apple pomace. Among various conditions, the best concentration of apple pomace and cultivation time for the production of laccase by P. ostreatus was 2.5% and 9 days, respectively. Reverse transcription polymerase chain reaction analyses of laccase isoenzyme genes, including pox1, pox3, pox4, poxc, poxa3, and poxa1b, revealed a clear effect of apple pomace on transcription induction. Our findings reveal that the use of apple pomace can be a model for the valuable addition of similar wastes and for the development of a solid-state fermenter and commercial production of oyster mushroom P. ostreatus.
Fungi* ; Laccase* ; Pleurotus* ; Polymerase Chain Reaction ; Reverse Transcription

The laccase (PpLAC) gene family members in peach fruit were identified and the relationship between their expression pattern and chilling induced browning were investigated. The study was performed using two varieties of peaches with different chilling tolerance, treated with or without exogenous γ-aminobutyric acid (GABA) during cold storage. Twenty-six genes were screened from the peach fruit genome. These genes were distributed on 6 chromosomes and each contained 5-7 exons. The PpLAC gene family members shared relatively similar gene structure and conserved motifs, and they were classified into 7 subgroups based on the cluster analysis. Transcriptome sequencing revealed that the expression levels of PpLAC7 and PpLAC9 exhibited an increasing pattern under low temperature storage, and displayed a similar trend with the browning index of peach fruit. Notably, GABA treatment reduced the degree of browning and inhibited the expression of PpLAC7 and PpLAC9. These results suggested that PpLAC7 and PpLAC9 might be involved in the browning of peach fruit during cold storage.
Food Storage ; Fruit/genetics* ; Laccase/genetics* ; Prunus persica/genetics*

In this study, the relationship between mycelium morphology and laccase production was studied. The results indicated that the morphology of P. ferulae pellets was changed when glass beads were added. Laccase production showed higher with spherical mycelium than with filamentous or flocculent mycelium. In addition, the spherical mycelium with a diameter of 0.2-0.4 mm highly affected laccase production. Effect of the composition of culture medium on pellets was investigated and results indicated that various concentrations of glucose, corn meal and wheat bran were important to the formation of pellets in diameter of 0.2-0.4 mm. Besides nutrients, the addition of non-nutritional substrates influenced the distribution of P. ferulae pellets. However, the production of laccase was not promoted by non-nutritional substrates.
Culture Media ; Fermentation ; Glass ; chemistry ; Industrial Microbiology ; Laccase ; biosynthesis ; Mycelium ; cytology ; growth & development ; Pleurotus ; cytology ; enzymology

Laccases (benzenediol: oxygen oxidoreductases; EC 1.10.3.2) are copper-containing polyphenol oxidases that can oxidize a wide range of aromatic compounds, concomitantly with the transfer of four electrons and the reduction of molecular oxygen to water. The progress on the research of laccases structure and function is reviewed. Their three-dimensional structures and catalytic mechanism, as well as their applications in different fields are emphasized.
Catalysis ; Hydrocarbons, Aromatic ; isolation & purification ; metabolism ; Laccase ; chemistry ; metabolism ; Oxidation-Reduction