scholarly journals Evaluation of Laccase Activities by Three Newly Isolated Fungal Species in Submerged Fermentation With Single or Mixed Lignocellulosic Wastes

2021 ◽  
Vol 12 ◽  
Author(s):  
Mei-Ling Han ◽  
Jing Yang ◽  
Ze-Yang Liu ◽  
Chun-Rui Wang ◽  
Si-Yu Chen ◽  
...  

Three newly isolated fungal species, namely, Cerrena unicolor Han 849, Lenzites betulina Han 851, and Schizophyllum commune Han 881, isolated from their native habitats in Wulingshan National Nature Reserve of Hebei Province of northern China, were screened for laccase production with single or mixed lignocellulosic wastes. C. unicolor Han 849 was found to express the highest levels of laccase with single or mixed lignocellulosic wastes compared with L. betulina Han 851 and S. commune Han 881. The highest laccase activity from the mixed fungal culture of C. unicolor Han 849 and S. commune Han 881 or L. betulina Han 851 on Firmiana platanifolia was 1,373.12 ± 55.93 and 1,144.85 ± 34.97 U/L, respectively, higher than that from other tested conditions. L. betulina Han 851 or S. commune Han 881 mixed with other species was also helpful for accelerating laccase secretion due to reach maximum enzyme activity quickly. The treatment of mixing different species, including the mixture of two or three species, was obviously conducive to the improvement of laccase activity on Firmiana platanifolia. These results revealed that the fungal co-culture and the mixed lignocellulosic wastes contribute to the improvement of laccase activities and enhance laccase activities within a short period. These findings would be helpful for providing a new method for rapid production of low-cost laccase and for optimization of integrated industrial laccase production.

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 9166-9179
Author(s):  
Qi An ◽  
Jie Qiao ◽  
Lu-Sen Bian ◽  
Mei-Ling Han ◽  
Xun-You Yan ◽  
...  

Different Pleurotus ostreatus and Flammulina velutipes species were compared relative to their ability to produce laccase in submerged fermentation of various lignocellulosic wastes. Fungi cultivation in identical culture conditions revealed wide differences among both species and strains of the same species. The laccase secretion ability of P. ostreatus strains was superior to F. velutipes strains. Maximum laccase production on cottonseed hull, corncob, and poplar wood was secreted by P. ostreatus CY 568, P. ostreatus CCEF 89, and P. ostreatus CY 568, respectively. The nature of lignocellulosic materials played an important role in determining the expression of laccase potential of fungi. The presence of cottonseed hull improved laccase activity and accelerated the rate of enzyme production. Maximum laccase production on cottonseed hull was nearly 1.29-fold and 1.53-fold higher than that on corncob and poplar wood, respectively. Laccase activity was detected in almost all tested strains on cottonseed hull on the first day, while only a few strains on poplar wood and corncob were detected on the first day. These findings will be helpful for selecting the appropriate strain in industrial applications and for optimization of integrated industrial laccase production.


2004 ◽  
Vol 70 (11) ◽  
pp. 6379-6384 ◽  
Author(s):  
Alexandra M. C. R. Alves ◽  
Eric Record ◽  
Anne Lomascolo ◽  
Karin Scholtmeijer ◽  
Marcel Asther ◽  
...  

ABSTRACT An efficient transformation and expression system was developed for the industrially relevant basidiomycete Pycnoporus cinnabarinus. This was used to transform a laccase-deficient monokaryotic strain with the homologous lac1 laccase gene placed under the regulation of its own promoter or that of the SC3 hydrophobin gene or the glyceraldehyde-3-phosphate dehydrogenase (GPD) gene of Schizophyllum commune. SC3-driven expression resulted in a maximal laccase activity of 107 nkat ml−1 in liquid shaken cultures. This value was about 1.4 and 1.6 times higher in the cases of the GPD and lac1 promoters, respectively. lac1-driven expression strongly increased when 25 g of ethanol liter−1 was added to the medium. Accordingly, laccase activity increased to 1,223 nkat ml−1. These findings agree with the fact that ethanol induces laccase gene expression in some fungi. Remarkably, lac1 mRNA accumulation and laccase activity also strongly increased in the presence of 25 g of ethanol liter−1 when lac1 was expressed behind the SC3 or GPD promoter. In the latter case, a maximal laccase activity of 1,393 nkat ml−1 (i.e., 360 mg liter−1) was obtained. Laccase production was further increased in transformants expressing lac1 behind its own promoter or that of GPD by growth in the presence of 40 g of ethanol liter−1. In this case, maximal activities were 3,900 and 4,660 nkat ml−1, respectively, corresponding to 1 and 1.2 g of laccase per liter and thus representing the highest laccase activities reported for recombinant fungal strains. These results suggest that P. cinnabarinus may be a host of choice for the production of other proteins as well.


2018 ◽  
Vol 8 (02) ◽  
pp. 77
Author(s):  
Hendro Risdianto ◽  
Elis Sofianti ◽  
Suraya Suraya ◽  
Sri Harjati Suhardi ◽  
Tjandra Setiadi

Lakase merupakan salah satu enzim ligninolitik yang memiliki kemampuan mendegradasi lignin. Lakase telah diproduksi menggunakan jamur pelapuk putih Marasmius sp. dalam Fermentasi Kultur Padat (FKP) menggunakan jerami padi sebagai media pertumbuhan. Pengaruh sumber karbon yaitu glukosa, gliserol, dan molase dalam medium produksi lakase digunakan dalam penelitian ini. Konsentrasi 0,5%; 1,0%; dan 2,0% digunakan untuk tiap jenis sumber karbon. Hasil menunjukkan bahwa aktivitas tertinggi lakase diperoleh pada kultivasi hari ke 6-10  dengan masing-masing aktivitas (872,0 U/L (hari ke-6), 1516,67 U/L (hari ke-9) dan 1270,69 U/L (hari ke-10). Aktivitas lakase tertinggi diperoleh pada penggunaan medium gliserol dan molase masing-masing adalah 1422,36 U/L (pada konsentrasi 1%, hari ke-7) dan 113,19 U/L (pada konsentrasi 2%, hari ke-8). Aktivitas tertinggi tersebut sebanding dengan penggunaan medium glukosa. Oleh karena itu, gliserol dan molase dapat digunakan sebagai alternatif sumber karbon untuk produksi lakase dengan fermentasi kultur padat.Kata kunci: glukosa, gliserol, lakase, molase, Marasmius sp., fermentasi kultur padat Influence of Carbon Sources on Laccase Production by White Rot Fungus Marasmius sp. in Solid State FermentationAbstractLaccase is an one of the ligninolytic enzymes that capable to degrade lignin in biomass. Laccase has been produced by white rot fungus Marasmius sp. in Solid State Fermentation (SSF) using rice straw as the solid support media. The influence of carbon sources, i.e. glucose, glycerol and molasses in medium of laccase production were studied in this paper. The concentration of 0.5%, 1.0% and 2.0% were used for each carbon sources. The results showed that the highest lacase activity was obtained within 6-10 days of cultivation. Glucose concentration of 0.5%, 1.0% and 2.0% gave the highest laccase activity were 872.0 U/L (day 6), 1516.67 U/L (day 9) and 1270.69 U/L (day 10) respectively. The highest laccase activity on using glycerol and molasses was 1422.36 U/L (at concentration of 1 % on day 7th) and 1113.19 U/L (at concentration of 2% on day 8th), respectively. This activity was comparable to that of glucose substrate. Therefore, glycerol and molasses gave a potential chance as carbon sources for the strategy on low cost laccase production in solid state fermentation.Keywords: glucose, glycerol, laccase, molasses, Marasmius sp., solid state fermentation. 


2020 ◽  
Author(s):  
Caroline Henn ◽  
Diego Alves Monteiro ◽  
Mauricio Boscolo ◽  
Roberto da Silva ◽  
Eleni Gomes

Abstract Atrazine is one of the most widespread chlorinated herbicides, leaving large bulks in soils and groundwater. Some bacterial strains can degrade atrazine, but little is known if fungal species have the same ability. Thus, we investigated the toxicity and degradation of atrazine by 13 basidiomycete strains. In liquid medium, P. cubensis SXS320, Gloelophyllum striatum MCA7, and Agaricales MCA17 removed 30, 37, and 38%, respectively, of initial 25 mg.L-1 of herbicide within 20 days. Deficiency of nitrogen drove atrazine degradation by Pluteus cubensis SXS320 and also induced synthesis and secretion of extracellular laccases by Datronia caperata MCA5, Pycnoporus sanguineus MCA16, and P. tenuiculus MCA11. Enzyme levels in contaminated medium of P. tenuiculus MCA11 were 13.3 fold superior than in control. However, we found no relationship between laccase production and the ability to metabolize atrazine. Laccase from P. tenuiculus MCA11 was incubated under optimal physico-chemical conditions for catalysis (pH 2.5 and 40º C), with an atrazine solution. Although 88% of initial laccase activity remained after 6h, no evidence of in vitro degradation was observed, even though ABTS was present as mediator.


BMC Biology ◽  
2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Amrita Srivathsan ◽  
Emily Hartop ◽  
Jayanthi Puniamoorthy ◽  
Wan Ting Lee ◽  
Sujatha Narayanan Kutty ◽  
...  

Abstract Background More than 80% of all animal species remain unknown to science. Most of these species live in the tropics and belong to animal taxa that combine small body size with high specimen abundance and large species richness. For such clades, using morphology for species discovery is slow because large numbers of specimens must be sorted based on detailed microscopic investigations. Fortunately, species discovery could be greatly accelerated if DNA sequences could be used for sorting specimens to species. Morphological verification of such “molecular operational taxonomic units” (mOTUs) could then be based on dissection of a small subset of specimens. However, this approach requires cost-effective and low-tech DNA barcoding techniques because well-equipped, well-funded molecular laboratories are not readily available in many biodiverse countries. Results We here document how MinION sequencing can be used for large-scale species discovery in a specimen- and species-rich taxon like the hyperdiverse fly family Phoridae (Diptera). We sequenced 7059 specimens collected in a single Malaise trap in Kibale National Park, Uganda, over the short period of 8 weeks. We discovered > 650 species which exceeds the number of phorid species currently described for the entire Afrotropical region. The barcodes were obtained using an improved low-cost MinION pipeline that increased the barcoding capacity sevenfold from 500 to 3500 barcodes per flowcell. This was achieved by adopting 1D sequencing, resequencing weak amplicons on a used flowcell, and improving demultiplexing. Comparison with Illumina data revealed that the MinION barcodes were very accurate (99.99% accuracy, 0.46% Ns) and thus yielded very similar species units (match ratio 0.991). Morphological examination of 100 mOTUs also confirmed good congruence with morphology (93% of mOTUs; > 99% of specimens) and revealed that 90% of the putative species belong to the neglected, megadiverse genus Megaselia. We demonstrate for one Megaselia species how the molecular data can guide the description of a new species (Megaselia sepsioides sp. nov.). Conclusions We document that one field site in Africa can be home to an estimated 1000 species of phorids and speculate that the Afrotropical diversity could exceed 200,000 species. We furthermore conclude that low-cost MinION sequencers are very suitable for reliable, rapid, and large-scale species discovery in hyperdiverse taxa. MinION sequencing could quickly reveal the extent of the unknown diversity and is especially suitable for biodiverse countries with limited access to capital-intensive sequencing facilities.


2021 ◽  
Vol 22 (3) ◽  
pp. 1157
Author(s):  
Pablo Aza ◽  
Felipe de Salas ◽  
Gonzalo Molpeceres ◽  
David Rodríguez-Escribano ◽  
Iñigo de la Fuente ◽  
...  

Laccases secreted by saprotrophic basidiomycete fungi are versatile biocatalysts able to oxidize a wide range of aromatic compounds using oxygen as the sole requirement. Saccharomyces cerevisiae is a preferred host for engineering fungal laccases. To assist the difficult secretion of active enzymes by yeast, the native signal peptide is usually replaced by the preproleader of S. cerevisiae alfa mating factor (MFα1). However, in most cases, only basal enzyme levels are obtained. During directed evolution in S. cerevisiae of laccases fused to the α-factor preproleader, we demonstrated that mutations accumulated in the signal peptide notably raised enzyme secretion. Here we describe different protein engineering approaches carried out to enhance the laccase activity detected in the liquid extracts of S. cerevisiae cultures. We demonstrate the improved secretion of native and engineered laccases by using the fittest mutated α-factor preproleader obtained through successive laccase evolution campaigns in our lab. Special attention is also paid to the role of protein N-glycosylation in laccase production and properties, and to the introduction of conserved amino acids through consensus design enabling the expression of certain laccases otherwise not produced by the yeast. Finally, we revise the contribution of mutations accumulated in laccase coding sequence (CDS) during previous directed evolution campaigns that facilitate enzyme production.


2021 ◽  
Vol 6 (1) ◽  
pp. 91-98
Author(s):  
A. Bello ◽  
◽  
J. B. Ameh ◽  
D. A. Machido ◽  
A. I. Mohammed-Dabo

Laccases are oxidases with broad substrate specificity and ability to oxidize various phenolic and non-phenolic compounds. This study was carried out to isolate and characterizes laccase producing fungi from environment samples. Soil and decaying wood samples were collected from different locations within Ahmadu Bello University, Zaria Main campus. Suspensions of the samples (1 g in 10 mL sterile distilled water) were serially diluted, inoculated onto Potato Dextrose Agar (PDA) containing 0.01% Chloramphenicol and incubated for 7 days at 30oC.The fungal isolates were characterized macroscopically and microscopically with the aid of an atlas. The identified fungal isolates were screened for laccase production by inoculating onto PDA containing 0.02% Guaiacol, 1mM ABTS (2 2’-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) and 0.5% Tannic acid as indicator compounds and incubated at 250C for 7 days. The laccase producing isolates were confirmed molecularly by ITS rDNA sequence analysis using the FASTA algorithm with the Fungus database from the European Bioinformatics Institute (EBI).A total of 25 fungal species (11 from soil and 14 from decaying wood samples) were isolated. Two isolates from the soil origin identified as Curvularia lunata SSI7 (Accession No. QIE06317.1) and Fusarium clade VII SSI3 (Accession No. GQ505677) were found to produce laccase where Curvularia lunata SSI7 was able to oxidize all the indicator compounds used for the screening. Fusarium clade VII SSI3 was able to oxidize only 0.5% Tannic acid. Laccase producing Curvularia lunata and Fusarium clade VII were isolated from soil samples collected from ABU Zaria Main Campus. Keywords: laccase, fungi, soil, decaying wood


Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7919
Author(s):  
Sjoerd van Ratingen ◽  
Jan Vonk ◽  
Christa Blokhuis ◽  
Joost Wesseling ◽  
Erik Tielemans ◽  
...  

Low-cost sensor technology has been available for several years and has the potential to complement official monitoring networks. The current generation of nitrogen dioxide (NO2) sensors suffers from various technical problems. This study explores the added value of calibration models based on (multiple) linear regression including cross terms on the performance of an electrochemical NO2 sensor, the B43F manufactured by Alphasense. Sensor data were collected in duplicate at four reference sites in the Netherlands over a period of one year. It is shown that a calibration, using O3 and temperature in addition to a reference NO2 measurement, improves the prediction in terms of R2 from less than 0.5 to 0.69–0.84. The uncertainty of the calibrated sensors meets the Data Quality Objective for indicative methods specified by the EU directive in some cases and it was verified that the sensor signal itself remains an important predictor in the multilinear regressions. In practice, these sensors are likely to be calibrated over a period (much) shorter than one year. This study shows the dependence of the quality of the calibrated signal on the choice of these short (monthly) calibration and validation periods. This information will be valuable for determining short-period calibration strategies.


2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Diah Irawati Dwi Arini ◽  
Margaretta Christita ◽  
Julianus Kinho

Tangale Nature reserve is a conservation area located in Gorontalo that have the biodiversity typical of Wallacea bioregion including macroscopic fungi. The purpose of this study was to identify the fungal species diversity found in the Tangale Nature reserve as well as its potential use, considering that the information on species diversity of fungi in the Wallacea region is very limited. This research was conducted using the cruise method by identifying macroscopic fungi along the hiking trail of Tangale Nature Reserve. The macroscopic fungi were observed for its morphological characteristic include the colour, diameter, surface of the veil, the shape of the stem, the length and diameter of the stem, the lamella, including ring and pore, type of lamella and the type of volva. The research recorded the substrates and the location where the fungus was found. Data were analyzed descriptively qualitative. The results of the research identified 28 species of macroscopic fungi that included to the division Ascomycota and Basidiomycota. It belongs to 16 families and 8 orders  are Pezizales, Agaricales, Auriculariales, Boletales, Cantharellales, Gomphales, Polyporales, dan Russulales. Based on place to grow as much as 57,14% were found growing on decaying wood and 42,86% found growing in the soil/litter. Based on the potential of use, it has identified four species of mushrooms potentially as edible mushroom are Pleurotus ostreatus,  Auricularia auricula, Ramaria formosa, and Polyporus arcularius. 11 species of mushrooms potentially as medicinal mushroom are Calvatia craniiformis, Scleroderma citrinum, Lenzites betulina, Microporus flabelliformis, Coriolus versicolor, Microporus xanthopus, and Albatrellus confluens.  


2012 ◽  
Vol 2012 ◽  
pp. 1-9
Author(s):  
Francisco Miranda

In the last years the small satellites have played an important role in the technological development. The attractive short period of design and low cost of them and the capacity to solve problems that are usually considered as problems to big and expensive spacecrafts lead us to study the control problem of these satellites. Active three-axis magnetic attitude stabilization of a low Earth orbit satellite is considered in this work. The control is created by interaction between the magnetic moment generated by magnetorquers mounted on the satellite body and the geomagnetic field. This problem is quite complex and difficult to solve. To overcome this difficulty guidance control is considered, where we use ε-strategies introduced by Pontryagin in the frame of differential games theory. Qualitative analysis and results of numerical simulation are presented.


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