scholarly journals Symbiotic Fungi Produce Laccases Potentially Involved in Phenol Degradation in Fungus Combs of Fungus-Growing Termites in Thailand

2005 ◽  
Vol 71 (12) ◽  
pp. 7696-7704 ◽  
Author(s):  
Yaovapa Taprab ◽  
Toru Johjima ◽  
Yoshimasa Maeda ◽  
Shigeharu Moriya ◽  
Savitr Trakulnaleamsai ◽  
...  
Keyword(s):  
Gene Product ◽  
Laccase Activity ◽  
Phenol Degradation ◽  
Plant Litter ◽  
Partial Purification ◽  
Copper Binding ◽  
Degenerate Primers ◽  
Fungus Combs ◽  
Fungus Comb ◽  
Symbiotic Fungi

ABSTRACT Fungus-growing termites efficiently decompose plant litter through their symbiotic relationship with basidiomycete fungi of the genus Termitomyces. Here, we investigated phenol-oxidizing enzymes in symbiotic fungi and fungus combs (a substrate used to cultivate symbiotic fungi) from termites belonging to the genera Macrotermes, Odontotermes, and Microtermes in Thailand, because these enzymes are potentially involved in the degradation of phenolic compounds during fungus comb aging. Laccase activity was detected in all the fungus combs examined as well as in the culture supernatants of isolated symbiotic fungi. Conversely, no peroxidase activity was detected in any of the fungus combs or the symbiotic fungal cultures. The laccase cDNA fragments were amplified directly from RNA extracted from fungus combs of five termite species and a fungal isolate using degenerate primers targeting conserved copper binding domains of basidiomycete laccases, resulting in a total of 13 putative laccase cDNA sequences being identified. The full-length sequences of the laccase cDNA and the corresponding gene, lcc1-2, were identified from the fungus comb of Macrotermes gilvus and a Termitomyces strain isolated from the same fungus comb, respectively. Partial purification of laccase from the fungus comb showed that the lcc1-2 gene product was a dominant laccase in the fungus comb. These findings indicate that the symbiotic fungus secretes laccase to the fungus comb. In addition to laccase, we report novel genes that showed a significant similarity with fungal laccases, but the gene product lacked laccase activity. Interestingly, these genes were highly expressed in symbiotic fungi of all the termite hosts examined.

scholarly journals Produksi dan karakterisasi lakase Omphalina sp. Production and characterization of Omphalina sp. laccase

2016 ◽  
Vol 75 (2) ◽  
Author(s):  
. SISWANTO ◽  
. SUHARYANTO ◽  
Rossy FITRIA
Keyword(s):  
Oil Palm ◽  
Laccase Activity ◽  
Research Result ◽  
White Rot Fungi ◽  
White Rot ◽  
Partial Purification ◽  
Empty Fruit Bunches ◽  
Optimum Ph ◽  
Laccase Enzyme

SummaryOmphalina sp. a white-rot fungi (WRF)originated from oil palm plantation has abilityto degrade empty fruit bunches of oil palm(EFBOP) so that it is expected to producelaccase with high activity. The ability ofOmphalina sp. to produce laccase enzyme onliquid fermentation will be studied. The enzymewill also be partially purified andcharacterized. The research result showed thatthe highest enzyme activity (1.162 U/mL) wasobtained using glucose malt yeast (GMY)medium at room temperature for four days.The addition of 2,5-xylidine as an inducerproduced laccase earlier i.e two days, but theactivity of laccase was less active afterprolonged incubation compared to that ofcontrol. The laccase produced on mediumcontaining 2% EFBOP reached optimumactivity as much as 0.38 U/mL after 10 th daysof incubation. Partial purification of laccaseon Sephacryl S-200 HR column resulted58.23% of yield recovery with twice purity thanbefore. The optimum pH of laccase was 4.5.Laccase activity was stable even after heatedon 50 o C for 30 minutes, but then decreasedwhen heated until 60 o C. The laccase has K Mand V max as much as 0.15 mM and 0.56 U/mLrespectively.RingkasanOmphalina sp., adalah fungi pelapuk putih(FPP) hasil isolasi dari kebun kelapa sawityang diketahui mampu mendegradasi tandankosong kelapa sawit (TKKS) dengan cepatsehingga diharapkan mampu menghasilkanlakase dengan aktivitas tinggi. KemampuanOmphalina sp. menghasilkan enzim lakasepada fermentasi cair akan dipelajari. Selain itu,lakase yang dihasilkan akan dimurnikan secaraparsial serta dilakukan karakterisasi pH, suhu,dan konsentrasi substrat optimum. Hasilpenelitian menunjukkan bahwa Omphalina sp.menghasilkan lakase dengan aktivitas tertinggi(1,162 U/mL) pada medium glucose malt yeast(GMY) yang diinkubasikan pada suhu ruangselama empat hari. Penambahan 2,5-xilidinsebagai induser mempercepat produksi lakaselebih awal yaitu dalam waktu dua hari, namunaktivitasnya masih lebih rendah dibandingkandengan kontrol pada inkubasi lebih lanjut.Lakase dari Omphalina sp. juga dapatdiproduksi pada medium yang mengandung2% TKKS dan aktivitasnya mencapai0,38 U/mL yang diinkubasi dalam suhu ruangselama 10 hari. Pemurnian parsial pada kolomSephacryl S-200 HR menghasilkan rendemensebesar 58,23% dengan kemurnian dua kalinya.Aktivitas lakase optimum pada pH 4,5 dantetap stabil setelah pemanasan selama 30 menitpada suhu ruang hingga 50 o C dan menuruntajam pada suhu 60 o C. Lakase Omphalina sp.menghasilkan nilai K M dan V maks masing-masing sebesar 0,15 mM dan 0,56 U/mL.

scholarly journals cumA Multicopper Oxidase Genes from Diverse Mn(II)-Oxidizing and Non-Mn(II)-OxidizingPseudomonas Strains

2001 ◽  
Vol 67 (9) ◽  
pp. 4272-4278 ◽  
Author(s):  
Chris A. Francis ◽  
Bradley M. Tebo
Keyword(s):  
Phylogenetic Analysis ◽  
16S Rrna ◽  
Multicopper Oxidase ◽  
Copper Binding ◽  
Gene Sequences ◽  
Degenerate Primers ◽  
Oxidase Gene ◽  
Alternative Function ◽  
Rrna Sequences ◽  
16S Rrna Sequences

ABSTRACT A multicopper oxidase gene, cumA, required for Mn(II) oxidation was recently identified in Pseudomonas putida strain GB-1. In the present study, degenerate primers based on the putative copper-binding regions of the cumAgene product were used to PCR amplify cumA gene sequences from a variety of Pseudomonas strains, including both Mn(II)-oxidizing and non-Mn(II)-oxidizing strains. The presence of highly conserved cumA gene sequences in several apparently non-Mn(II)-oxidizing Pseudomonasstrains suggests that this gene may not be expressed, may not be sufficient alone to confer the ability to oxidize Mn(II), or may have an alternative function in these organisms. Phylogenetic analysis of both CumA and 16S rRNA sequences revealed similar topologies between the respective trees, including the presence of several distinct phylogenetic clusters. Overall, our results indicate that both thecumA gene and the capacity to oxidize Mn(II) occur in phylogenetically diverse Pseudomonas strains.

scholarly journals Improvement of laccase activity by silencing PacC in Ganoderma lucidum

2021 ◽  
Author(s):  
Mingwen Zhao ◽  
Jing Zhu ◽  
Shuqi Song ◽  
Lindan Lian ◽  
Liang Shi ◽  
...  
Keyword(s):  
Ganoderma Lucidum ◽  
Laccase Activity ◽  
Ph Value ◽  
Fold Increase ◽  
White Rot ◽  
White Rot Fungus ◽  
Copper Binding ◽  
Multicopper Oxidases ◽  
Binding Domains ◽  
Laccase Genes

Abstract Ganoderma lucidum is a representative white-rot fungus that has great potential to degrade lignocellulose biomass. Laccase is recognized as a class of the most important lignin-degrading enzymes in G. lucidum. However, the comprehensive regulatory mechanisms of laccase are still lacking. Based on the genome sequence of G. lucidum, 15 laccase genes were identified and their encoding proteins were analyzed in this study. All of the laccase proteins are predicted to be multicopper oxidases with conserved copper-binding domains. Most laccase proteins were secreted enzymes in addition to Lac14 in which the signal peptide could not be predicted. The activity of all laccases showed the highest level at pH 3.0 or pH 7.0, with total laccase activity of approximately 200 U/mg protein. Silencing PacC resulted in a 5.2 fold increase in laccase activity compared with WT. Five laccase genes (lac1, lac6, lac9, lac10 and lac14) showed an increased transcription levels (approximately 1.5-5.6 fold) in the PacC-silenced strains versus that in WT, while other laccase genes were downregulated or unchanged. The extracellular pH value was about 3.1, which was more acidic in the PacC-silenced strains than in the WT (pH 3.5). Moreover, maintaining the fermentation pH resulted in a downregulation of laccase activity which is induced by silencing PacC Our findings indicate that in addition to its function in acidification of environmental pH, PacC plays an important role in regulating laccase activity in fungi.

scholarly journals Caste-specific nutritional differences define carbon and nitrogen fluxes within symbiotic food webs in African termite mounds

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Risto Vesala ◽  
Laura Arppe ◽  
Jouko Rikkinen
Keyword(s):  
Stable Isotopes ◽  
General Mechanism ◽  
Food Chains ◽  
Fungal Mycelium ◽  
Termite Mounds ◽  
Carbon And Nitrogen ◽  
Plant Matter ◽  
Stable Isotope Signatures ◽  
Fungus Comb ◽  
Symbiotic Fungi

Abstract Fungus-growing termites of the genus Macrotermes cultivate symbiotic fungi (Termitomyces) in their underground nest chambers to degrade plant matter collected from the environment. Although the general mechanism of food processing is relatively well-known, it has remained unclear whether the termites get their nutrition primarily from the fungal mycelium or from plant tissues partly decomposed by the fungus. To elucidate the flows of carbon and nitrogen in the complicated food-chains within the nests of fungus-growing termites, we determined the stable isotope signatures of different materials sampled from four Macrotermes colonies in southern Kenya. Stable isotopes of carbon revealed that the termite queen and the young larvae are largely sustained by the fungal mycelium. Conversely, all adult workers and soldiers seem to feed predominantly on plant and/or fungus comb material, demonstrating that the fungal symbiont plays a different nutritional role for different termite castes. Nitrogen stable isotopes indicated additional differences between castes and revealed intriguing patterns in colony nitrogen cycling. Nitrogen is effectively recycled within the colonies, but also a presently unspecified nitrogen source, most likely symbiotic nitrogen-fixing bacteria, seems to contribute to nitrogen supply. Our results indicate that the gut microbiota of the termite queen might be largely responsible for the proposed nitrogen fixation.

Production of metabolic gases by nests of the termite Macrotermes jeanneli in Kenya

1997 ◽  
Vol 13 (4) ◽  
pp. 491-510 ◽  
Author(s):  
J. P. E. C. Darlington ◽  
P. R. Zimmerman ◽  
J. Greenberg ◽  
C. Westberg ◽  
P. Bakwin
Keyword(s):  
Carbon Dioxide ◽  
Water Loss ◽  
Population Data ◽  
Gas Production ◽  
Nest Size ◽  
Tree Roots ◽  
Excess Carbon ◽  
Fungus Combs ◽  
Direct Observations ◽  
Fungus Comb

ABSTRACTNests of a fungus-growing termite Macrotermes jeanneli discharge all their metabolic gases through a single outlet to the atmosphere. This made it possible to measure the production of metabolic gases, and the rates of water loss, for intact nests in the field. Rates of production of carbon dioxide and methane from isolated nest components (different termite castes and intact fungus combs) were measured. Using previously published nest population data and fungus comb weights in relation to nest size, the expected gas production rates for intact nests were calculated. These estimates were compared with direct observations of the gaseous outflow from intact nests. The rates were in reasonable agreement, but some nests emitted excess carbon dioxide, probably produced by respiration of tree roots and non-termite soil organisms. Large nests may have a total gas outflow of 100,000 to 400,000 1 d–1 including 800 to 1500 1 d–1 of CO2 and 0.5 to 1.3 1 d–1 of CH4. Nests lose water at the rate of up, to 13 1 d–1 gross, but allowing for ambient humidity the net water loss was up to about 5 1 d–1. Some of this is metabolic water, but the larger proportion comes from the soil. Area-based estimates of gas production were made for this and two other species of Macrotermes, but they are not accurate because the field distribution and mound density are not adequately known.

scholarly journals Substrate Preference Determines Macrofungal Biogeography in the Greater Mekong Sub-Region

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 824 ◽  
Author(s):  
Ye ◽  
Li ◽  
Mortimer ◽  
Xu ◽  
Gui ◽  
...  
Keyword(s):  
Taxonomic Diversity ◽  
Plant Litter ◽  
Substrate Preference ◽  
Secondary Forests ◽  
Saprotrophic Fungi ◽  
Multiple Substrates ◽  
Substrate Preferences ◽  
Symbiotic Fungi ◽  
Greater Mekong Subregion

The availability and the quality of substrates are important drivers of macrofungal biogeography, and thus macrofungal species occurrence is potentially dependent on the availability of different substrates. However, few studies have explored the properties of macrofungal substrates and assessed the relationship between macrofungal diversity and substrate diversity at a landscape level. To address this issue, we conducted a landscape-scale survey of basidiocarp substrates in the Greater Mekong Subregion (GMS). A total of 957 macrofungal species distributed across 73 families and 189 genera were collected. Substrates of these macrofungi were categorized into four main groups (namely, litter, soil, root, and rare substrates) and referenced into 14 sub-substrate types (such as branches, leaves, and fruit). The results revealed that 50% of the observed macrofungal species were symbiotrophs living in ectomycorrhizal association with plant hosts, 30% were saprotrophs decomposing plant litter, 15% lived in soil organic matter, and 5% lived in rare substrates. The most abundant root symbiotic fungi were members of Russula, whereas most litter saprotrophic fungi belonged to Marasmius. Macrofungi commonly favored a single substrate. This specificity was not affected by changes in vegetation or climate. Less than 1% of macrofungi (e.g., Marasmius aff. maximus) could live on multiple substrates. Most of these unusual macrofungi were characterized as highly mobile and were generally found in successional areas. In secondary forests, our survey indicated that significant correlations exist between substrate preference and taxonomic diversity, reflected as higher substrate diversity generally accompanied by higher macrofungal diversity. In conclusion, substrate preference is an important factor driving macrofungal composition and distribution in the GMS. Macrofungi that thrive on multiple substrates constitute pioneer groups that have an important role in establishing macrofungal communities in new habitats. These observations have furthered our understanding of how substrate preferences could explain macrofungal biogeography.

scholarly journals Produksi dan karakterisasi lakase Omphalina sp. Production and characterization of Omphalina sp. laccase

2016 ◽  
Vol 75 (2) ◽  
Author(s):  
. SISWANTO ◽  
. SUHARYANTO ◽  
Rossy FITRIA
Keyword(s):  
Oil Palm ◽  
Laccase Activity ◽  
Research Result ◽  
White Rot Fungi ◽  
White Rot ◽  
Partial Purification ◽  
Empty Fruit Bunches ◽  
Optimum Ph ◽  
Laccase Enzyme

SummaryOmphalina sp. a white-rot fungi (WRF)originated from oil palm plantation has abilityto degrade empty fruit bunches of oil palm(EFBOP) so that it is expected to producelaccase with high activity. The ability ofOmphalina sp. to produce laccase enzyme onliquid fermentation will be studied. The enzymewill also be partially purified andcharacterized. The research result showed thatthe highest enzyme activity (1.162 U/mL) wasobtained using glucose malt yeast (GMY)medium at room temperature for four days.The addition of 2,5-xylidine as an inducerproduced laccase earlier i.e two days, but theactivity of laccase was less active afterprolonged incubation compared to that ofcontrol. The laccase produced on mediumcontaining 2% EFBOP reached optimumactivity as much as 0.38 U/mL after 10 th daysof incubation. Partial purification of laccaseon Sephacryl S-200 HR column resulted58.23% of yield recovery with twice purity thanbefore. The optimum pH of laccase was 4.5.Laccase activity was stable even after heatedon 50 o C for 30 minutes, but then decreasedwhen heated until 60 o C. The laccase has K Mand V max as much as 0.15 mM and 0.56 U/mLrespectively.RingkasanOmphalina sp., adalah fungi pelapuk putih(FPP) hasil isolasi dari kebun kelapa sawityang diketahui mampu mendegradasi tandankosong kelapa sawit (TKKS) dengan cepatsehingga diharapkan mampu menghasilkanlakase dengan aktivitas tinggi. KemampuanOmphalina sp. menghasilkan enzim lakasepada fermentasi cair akan dipelajari. Selain itu,lakase yang dihasilkan akan dimurnikan secaraparsial serta dilakukan karakterisasi pH, suhu,dan konsentrasi substrat optimum. Hasilpenelitian menunjukkan bahwa Omphalina sp.menghasilkan lakase dengan aktivitas tertinggi(1,162 U/mL) pada medium glucose malt yeast(GMY) yang diinkubasikan pada suhu ruangselama empat hari. Penambahan 2,5-xilidinsebagai induser mempercepat produksi lakaselebih awal yaitu dalam waktu dua hari, namunaktivitasnya masih lebih rendah dibandingkandengan kontrol pada inkubasi lebih lanjut.Lakase dari Omphalina sp. juga dapatdiproduksi pada medium yang mengandung2% TKKS dan aktivitasnya mencapai0,38 U/mL yang diinkubasi dalam suhu ruangselama 10 hari. Pemurnian parsial pada kolomSephacryl S-200 HR menghasilkan rendemensebesar 58,23% dengan kemurnian dua kalinya.Aktivitas lakase optimum pada pH 4,5 dantetap stabil setelah pemanasan selama 30 menitpada suhu ruang hingga 50 o C dan menuruntajam pada suhu 60 o C. Lakase Omphalina sp.menghasilkan nilai K M dan V maks masing-masing sebesar 0,15 mM dan 0,56 U/mL.

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