scholarly journals Production of Fungal Laccase under Solid State Bioprocessing of Agroindustrial Waste and Its Application in Decolourization of Synthetic Dyes

Author(s):  
Benjamin Vandelun Ado ◽  
Abiodun Anthony Onilude ◽  
Hyacinth Ocheigwu Apeh Oluma ◽  
Daniel Malo Mabitine

Fungal laccases are preferred due to high redox potentials and low substrate specificity to xenobiotics including synthetic dyes. For large-scale applications, low enzyme yield and high cost of production has remained the challenge. Agroindustrial waste such as saw-dust of Terminalia superba abounds locally and was utilized as low-cost alternative substrate for laccase production in Solid State Bioprocessing (SSB) using Trametes sp. isolate G31. The study optimized laccase production using various parameters. Optimal production of laccase was at pH 5.0 - 7.0 with 2356 U/mL - 2369 U/mL and 25°C (2336 U/mL). Among the sources of nitrogen and carbon tested, laccase production in ammonium sulphate and sucrose supplemented media were higher. The effect of activators on laccases production showed that Cu2+ and Ca2+induced high titres of laccase at 4 -5 mM and 2 - 4 mM respectively, while production of laccase by Mn2+ was significantly high at 40 mM. The effect of 2, 2-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), guaiacol and varatryl alcohol on laccase production was significantly different especially in glycerol. Optimum production for laccase was on day 14 with 2356 U/mL followed by steady declined up to day 34. The purified laccase had a specific activity of 5008 µmol/min/mg, purification factor of 3.85, and a molecular mass of ~40 kDa using N-PAGE. The potential of crude laccase to decolourize diverse dyes was tested. Phenol red achieved 40% decolourization for 1hr, while RBBR (93%), Crystal violet (60%), Methylene blue (53%) and Congo red (51%) for 24 hr, 72 hr, 48 hr and 120 hr respectively. Methyl red and Malachite green attained 42% (72 hr) and 32% (48 hr) decolourization. The enzyme ability to oxidize Phenol red and other synthetic dyes without mediators made it eco-friendly in treating dye wastewaters.

Author(s):  
Benjamin Vandelun Ado ◽  
Tivkaa Joseph Amande ◽  
Esther E. Ebah ◽  
Daniel Malo Mabitine

The search for efficient and green oxidation technologies has increased interest in utilization of laccases in non conventional methods. Laccases catalyze a wide range of substrates due to low substrate specificity and strong oxidative potentials. Challenges to large-scale enzyme utilization include, low enzyme activity and instability which restrict use in many areas of biotechnology. In the study, 59 fungi comprising Aspergillus niger (40%), Trichoderma harzianum (31%), Aspergillus flavus (9.0%), Trichoderma viride (5.0%), Fusarium oxysporum (5.0%), Rhizopus stolonifer (5.0%), Trametes sp. (3.0%) and Aspergillus nidulans (2.0%) were isolated and screened for laccase production. Plate screening test showed 57.5%, 34.0% and 8.5% of fungi were laccase-positive on ABTS, Guaiacol, and α-naphthol agar respectively. Isolates were further screened in liquid cultures, and the highest laccase producer identified molecularly. Trametes sp isolate B7 was selected for solid state fermentation (SSF). Laccase production in SSF was highest at pH 5.0 (2356 U/mL). The purified laccase showed high activity (pH 3.0 - 6.0) and stability (pH 3.0 - 8.5) using ABTS. It was active (20 - 80°C) and thermostable (30 - 80°C) with optimum stability at 70°C (100% for 1 hour). The percentage decolourization of Phenol red were 28% and 36% using 1000 U/mL and 2000 U/mL crude laccases respectively. Similarly, RBBR (100%), Congo red (75%) and Malachite green (62%), and 77.4%, 64% and 28% were decolourized using 1000 U/mL and 2000 U/mL crude laccases respectively. ABTS agar was very reliable in large-scale screening for laccase which possessed thermostable property and degraded synthetic dyes without use of enzyme mediators. These attribute made the enzyme suitable for application in industry and biotechnology.


2020 ◽  
Vol 42 ◽  
pp. e52699 ◽  
Author(s):  
Alex Graça Contato ◽  
Fabíola Dorneles In´ácio ◽  
Tatiane Brugnari ◽  
Caroline Aparecida Vaz de Araújo ◽  
Giselle Maria Maciel ◽  
...  

Laccases are oxidoreductase enzymes that have the ability to oxidize phenolic substrates. Its biotechnological potential has been greatly explored in many areas as biotechnology industry, bioremediation of dyes, food industry and environmental microbiology. The aim of this study was maximize the laccase production by Pleurotus pulmonarius (Fr.) Quélet in solid-state fermentation (SSF) using orange waste as substrate. After optimization the capability of the crude laccase to decolorize dyes was analyzed. The fermentation medium in the solid-state was optimized by applying a factorial design. After statistics optimization, laccase activity increased two times. The laccase activity appears to be correlated with the ability of crude extract to decolorize some industrial dyes. The optimized laccase was characterized with respect to optimum pH, influence of temperature and salts. Our results demonstrate that P. pulmonarius was an efficient producer of an important industrial enzyme, laccase, in a cheap solid-state system using orange waste as substrate.


2020 ◽  
Vol 31 (1) ◽  
Author(s):  
Tran Thi Kim Chi ◽  
Bui Thi Thu Hien ◽  
Hoang Nhu Thanh ◽  
Trinh Duc Thien ◽  
Pham Nguyen Hai

We report the large-scale synthesis of highly luminescent ZnSe nanocrystals (NCs) by a simple and low-cost hydrothermal method. XRD (X-ray Diffraction) and HR-TEM (High Resolution Transmission Microscopy) characterization studies confirmed the formation of as-synthesized ZnSe NCs in cubic structure. The optical property of ZnSe NCs were tunable via controlling the Zn:Se molar precursor ratio (0.5:1–1.5:1), reaction temperature (150–200 0C), and reaction time (5–30 h). The resulting ZnSe NCs with the Zn:Se precursor ratio of 1:1, hydrothermally treated at 190 0C for 20 h exhibited the highest photoluminescence quantum yield obtained by PL spectra with the 355 nm excitation. The current–voltage (I–V) characteristics of the ZnSe NCs show its promising application in the solid-state lighting.


2021 ◽  
Author(s):  
Dineshkumar Sengottuvelu ◽  
Abdul Kalam Shaik ◽  
Satish Mishra ◽  
Mahsa Abbaszadeh ◽  
Nathan Hammer ◽  
...  

Carbon quantum dots (CQDs) are fascinating luminous materials from the carbonaceous family and are increasingly being investigated in many optoelectronic applications due to their unique photoluminescence (PL) characteristics. Herein, we report the synthesis of nitrogen-doped carbon quantum dots (NCQDs) from citric acid and m-phenylenediamine using a one-pot hydrothermal approach. The environment-dependent emission changes of NCQDs were extensively investigated in various solvents, in solid-state, and in physically assembled PMMA-PnBA-PMMA copolymer gels in 2-ethyl hexanol. The NCQDs display bright emission in various solvents as well as in solid-state and a temperature-dependent enhanced emission in gels. In detail, these NCQDs exhibit multicolor PL emission across the visible region and its enhancement upon changing the environment (solutions and polymer matrices). The NCQDs also exhibit excitation-dependent PL and solvatochromism, which are rarely observed in CQDs. Most CQDs are non-emissive in the aggregated or solid-state due to the aggregation-caused quenching (ACQ) effect, limiting their solid-state applications. However, these NCQDs display a strong solid-state emission centered at 568 nm ascribed to the presence of abundant surface functional groups, which helps to prevent the - interaction between the NCQDs and to overcome the ACQ effect in the solid-state. Interestingly, the NCQD containing gels display a significant fluorescence enhancement than the NCQDs in 2-ethyl hexanol solution because of the interaction between the polar PMMA blocks and NCQDs. This research opens up the development of large-scale, low-cost multicolor phosphor for the fabrication of optoelectronic devices, sensing, and bioimaging applications.


Author(s):  
William C. Leighty

Alaska village survival is threatened by the high cost of imported fuels for heating, electricity generation, and vehicles. During Winter 2007–8, the price per gallon of heating oil and diesel generation fuel exceeded $8 in many villages. Many villagers were forced to move to Anchorage or Fairbanks. Although indigenous renewable energy (RE) resources may be adequate to supply a community’s total annual energy needs, the innate intermittent and seasonal output of the renewables — except geothermal, where available, which may be considered “baseload” — requires large-scale, low-cost energy storage to provide an annually-firm energy supply. Anhydrous ammonia, NH3, is the most attractive, carbon-free fuel for this purpose at Alaska village scale, because of its 17.8% mass hydrogen content and its high energy density as a low-pressure liquid, suitable for storage in inexpensive mild steel tanks. NH3 may be synthesized directly from renewable-source electricity, water, and atmospheric nitrogen (N2) via solid state ammonia synthesis (SSAS), a new process to be pioneered in Alaska.


2020 ◽  
Vol 50 ◽  
pp. 2060003
Author(s):  
N. Zaitseva ◽  
A. Glenn ◽  
A. Mabe ◽  
L. Carman ◽  
S. Payne

Detection of special nuclear materials (SNM) requires instruments that can detect and characterize uranium and plutonium isotopes, having at the same time the ability to discriminate among different types of radiation. For many decades, neutron detection has been based on 3He proportional counters sensitive primarily to thermal neutrons. The most common methods for detection of fast neutrons have been based on liquid scintillators with pulse shape discrimination (PSD). The shortage of 3He and handling issues with liquid scintillators stimulated a search for efficient solid-state PSD materials. Recent studies conducted at LLNL led to development of new materials, among which are organic crystals with excellent PSD and first PSD plastics for fast neutron detection. More advantages are introduced by plastics doped with neutron capture agents, such as 10B and 6Li, that can be used without moderation for combined detection of both thermal and fast neutrons, offering, in addition, a unique “triple” PSD for signal separation between fast neutrons, thermal neutrons, and gamma-rays. More recent studies have been focused on development of deuterated scintillators that can be used for neutron spectroscopy without time-of-flight (ToF). Among commercially produced materials are large-scale (>10 cm) stilbene crystals grown by the inexpensive solution technique, and different types of PSD plastics that, due to the deployment advantages and ease of fabrication, create a basis for the widespread use of solid-state scintillators as large-volume and low-cost neutron detectors.


BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5287-5300
Author(s):  
Qi An ◽  
Cong-Sheng Li ◽  
Jing Yang ◽  
Si-Yu Chen ◽  
Kai-Yue Ma ◽  
...  

Pleurotus ostreatus and a newly isolated Ganoderma lingzhi strain were evaluated for their laccase secretion capacity by solid-state fermentation with different agricultural and forestry residues. There was a significant difference among fungi for biosynthetic potential. In principle, the laccase secretion capacity of P. ostreatus CY 568 was stronger than that from G. lingzhi Han 500. Different species of fungi had a preference for agricultural and forestry residues. The presence of cottonseed hull and Populus beijingensis were helpful for accelerating the rate of laccase enzyme production of P. ostreatus CY 568. Cottonseed hull and corncob were useful for improving the production of laccase from G. lingzhi Han 500. Continuous and stable laccase production was found on cottonseed hull by P. ostreatus CY 568 and G. lingzhi Han 500. Maximum laccase activity obtained from P. ostreatus CY 568 on Toona sinensis, Sophora japonica, Salix babylonica, Populus beijingensis, corncob, cottonseed hull, and straw of Oryza sativa was higher than that from G. lingzhi Han 500, and was nearly 1.16-fold, 1.59-fold, 3.32-fold, 1.39-fold, 1.08-fold, 1.08-fold, and 1.36-fold, respectively. These findings will be helpful for developing new productive strains and expanding more species for industrial application to obtain efficient and low-cost laccase.


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. 


Author(s):  
James Dawson ◽  
Theodosios Famprikis ◽  
Karen E Johnston

Current commercial batteries cannot meet the requirements of next-generation technologies, meaning that the creation of new high-performance batteries at low cost is essential for the electrification of transport and large-scale...


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