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*

Two manganese peroxidases (MnPs), MnP1 and MnP2, and a laccase, Lac1, were purified from Trametes polyzona KU-RNW027. Both MnPs showed high stability in organic solvents which triggered their activities. Metal ions activated both MnPs at certain concentrations. The two MnPs and Lac1, played important roles in dye degradation and pharmaceutical products deactivation in a redox mediator-free system. They completely degraded Remazol brilliant blue (25 mg/L) in 10–30 min and showed high degradation activities to Remazol navy blue and Remazol brilliant yellow, while Lac1 could remove 75% of Remazol red. These three purified enzymes effectively deactivated tetracycline, doxycycline, amoxicillin, and ciprofloxacin. Optimal reaction conditions were 50 °C and pH 4.5. The two MnPs were activated by organic solvents and metal ions, indicating the efficacy of using T. polyzona KU-RNW027 for bioremediation of aromatic compounds in environments polluted with organic solvents and metal ions with no need for redox mediator supplements.
Amoxicillin ; Biodegradation, Environmental ; Ciprofloxacin ; Doxycycline ; Hydrogen-Ion Concentration ; Ions ; Laccase ; Manganese ; Oxidation-Reduction ; Peroxidases ; Pharmaceutical Preparations ; Solvents ; Tetracycline ; Trametes

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

Azo dyes containing effluents from different industries pose threats to the environment. Though there are physico-chemical methods to treat such effluents, bioremediation is considered to be the best eco-compatible technique. In this communication, we discuss the decolorization potentiality of five azo dyes by Podoscypha elegans (G. Mey.) Pat., a macro-fungus, found growing on the leaf-litter layer of Bethuadahari Wildlife Sanctuary in West Bengal, India. The fungus exhibited high laccase and very low manganese peroxidase activities under different culture conditions. Decolorization of five high-molecular weight azo dyes, viz., Orange G, Congo Red, Direct Blue 15, Rose Bengal and Direct Yellow 27 by the fungus was found to be positive in all cases. Maximum and minimum mean decolorization percentages were recorded in Rose Bengal (70.41%) and Direct Blue 15 (24.8%), respectively. This is the first record of lignolytic study and dye decolorization by P. elegans.
Azo Compounds ; Biodegradation, Environmental ; Citrus sinensis ; Congo Red ; Fungi ; India ; Laccase* ; Manganese ; Peroxidase ; Rose Bengal

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*

Temperature is an important environmental factor that can greatly influence the cultivation of Auricularia cornea. In this study, lignin peroxidase, laccase, manganese peroxidase, and cellulose in A. cornea fruiting bodies were tested under five different temperatures (20 °C, 25 °C, 30 °C, 35 °C, and 40 °C) in three different culture periods (10 days, 20 days and 30 days). In addition, the V4 region of bacterial 16S rRNA genes in the substrate of A. cornea cultivated for 30 days at different temperatures were sequenced using next-generation sequencing technology to explore the structure and diversity of bacterial communities in the substrate. Temperature and culture days had a significant effect on the activities of the four enzymes, and changes in activity were not synchronized with changes in temperature and culture days. Overall, we obtained 487,694 sequences from 15 samples and assigned them to 16 bacterial phyla. Bacterial community composition and structure in the substrate changed when the temperature was above 35 °C. The relative abundances of some bacteria were significantly affected by temperature. A total of 35 genera at five temperatures in the substrate were correlated, and 41 functional pathways were predicted in the study. Bacterial genes associated with the membrane transport pathway had the highest average abundance (16.16%), and this increased at 35 °C and 40 °C. Generally, different temperatures had impacts on the physiological activity of A. cornea and the bacterial community in the substrate; therefore, the data presented herein should facilitate cultivation of A. cornea.
Bacteria ; Cellulose ; Cornea* ; Fruit ; Genes, Bacterial ; Genes, rRNA ; Laccase ; Lignin ; Manganese ; Membranes ; Peroxidase

In mating of Lentinula edodes, dikaryotic strains generated from certain monokaryotic strains such as the B2 used in this study tend to show better quality of fruiting bodies regardless of the mated monokaryotic strains. Unlike B2, dikaryotic strains generated from B16 generally show low yields, with deformed or underdeveloped fruiting bodies. This indicates that the two nuclei in the cytoplasm do not contribute equally to the physiology of dikaryotic L. edodes, suggesting an expression bias in the allelic genes of the two nuclei. To understand the role of each nucleus in dikaryotic strains, we investigated single nucleotide polymorphisms (SNPs) in laccase genes of monokaryotic strains to reveal nuclear origin of the expressed mRNAs in dikaryotic strain. We performed reverse transcription PCR (RT-PCR) analysis using total RNAs extracted from dikaryotic strains (A5B2, A18B2, and A2B16) as well as from compatible monokaryotic strains (A5, A18, and B2 for A5B2 and A18B2; A2 and B16 for A2B16). RT-PCR results revealed that Lcc1, Lcc2, Lcc4, Lcc7, and Lcc10 were the mainly expressed laccase genes in the L. edodes genome. To determine the nuclear origin of these laccase genes, the genomic DNA sequences in monokaryotic strains were analyzed, thereby revealing five SNPs in Lcc4 and two in Lcc7. Subsequent sequence analysis of laccase mRNAs expressed in dikaryotic strains revealed that these were almost exclusively expressed from B2-originated nuclei in A5B2 and A18B2 whereas B16 nucleus did not contribute to laccase expression in A2B16 strain. This suggests that B2 nucleus dominates the expression of allelic genes, thereby governing the physiology of dikaryons.
Base Sequence ; Bias (Epidemiology) ; Cytoplasm ; Fruit ; Genome ; Laccase* ; Lentinula* ; Physiology ; Polymerase Chain Reaction ; Polymorphism, Single Nucleotide ; Reverse Transcription ; RNA ; RNA, Messenger ; Sequence Analysis ; Shiitake Mushrooms*

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

Regulation of alkaline-resistant laccase from Perenniporia tephropora KU-Alk4 was proved to be controlled by several factors. One important factor was the initial pH, which drove the fungus to produce different kinds of ligninolytic enzymes. P. tephropora KU-Alk4 could grow at pH 4.5, 7.0, and 8.0. The fungus produced laccase and MnP at pH 7.0, but only laccase at pH 8.0. The specific activity of laccase in the pH 8.0 culture was higher than that in the pH 7.0 culture. At pH 8.0, glucose was the best carbon source for laccase production but growth was better with lactose. Low concentrations of glucose at 0.1% to 1.0% enhanced laccase production, while concentrations over 1% gave contradictory results. Veratryl alcohol induced the production of laccase. A trace concentration of copper ions was required for laccase production. Biomass increased with an increasing rate of aeration of shaking flasks from 100 to 140 rpm; however, shaking at over 120 rpm decreased laccase quantity. Highest amount of laccase produced by KU-Alk4, 360 U/mL, was at pH 8.0 with 1% glucose and 0.2 mM copper sulfate, unshaken for the first 3 days, followed by addition of 0.85 mM veratryl alcohol and shaking at 120 rpm. The crude enzyme was significantly stable in alkaline pH 8.0~10.0 for 24 hr. After treating the pulp mill effluent with the KU-Alk4 system for 3 days, pH decreased from 9.6 to 6.8, with reduction of color and chemical oxygen demand at 83.2% and 81%, respectively. Laccase was detectable during the biotreatment process.
Biological Oxygen Demand Analysis ; Biomass ; Carbon ; Copper ; Copper Sulfate ; Fungi ; Glucose ; Hydrogen-Ion Concentration ; Ions ; Laccase* ; Lactose ; Physiology

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